principles of ecology.pdf

8/10/2019 Principles of Ecology.pdf

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University of EdinburghSchool of GeoSciences

PRINCIPLES

OF ECOLOGYThe Distribution andAbundance of Organisms

Course Information

2011/2012

Course OrganiserDr Gail JacksonInstitute of Atmospheric & Environmental SciencesRoom 217a Crew Building

Email: [email protected]

Course SecretaryHelen McKeatingRoom 211, Crew BuildingTel.: 0131 650 5430

Email: [email protected]

PRINCIPLES

OF

ECOLOGY


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TABLE OF CONTENTS

INTRODUCTION TO THE COURSE 3WELCOME 3COURSE SYNOPSIS 3ENTRY REQUIREMENTS 3

AIMS AND OBJECTIVES 3COURSE STRUCTURE 3PRACTICAL PROJECTS 4STAFF 4SYLVA 4TIMING 5LOCATIONS 5ASSESSMENT 6BOOK LIST 9

TIMETABLE 10/11

PRACTICAL PROJECTS 12TITLES 12

PREPARING PRACTICAL PROJECT REPORTS 12PROJECT MARK SHEET 14

SYNOPSES OF PRACTICAL PROJECTS 15PROJECT 1. THE EFFECT OF GORSE BURNING ON THE CARBON STOCK OF BLACKFORD HILL 15PROJECT 2. GERMINATION AND ESTABLISHMENT OF GORSE ULEX EUROPAEAON BLACKFORD HILL17PROJECT 3. NATURAL REGENERATION IN HERMITAGE WOOD 20PROJECT 4. THE IMPORTANCE OF EPILITHIC ALGAE FOR STREAM INVERTEBRATES 22PROJECT 5. VARIATION IN THE ABUNDANCE OF TAR SPOT INFECTION ON SYCAMORE LEAVES 24PROJECT 6. DISTRIBUTION OF SNAILS IN THE HERMITAGE OF BRAID 26PROJECT 7. RELATIONSHIPS BETWEEN BRYOPHYTE GROWTH FORM AND HABITAT 28PROJECT 8. DISTRIBUTION AND DIVERSITY OF SPECIES IN RELATION TO RABBIT GRAZING

ON BLACKFORD HILL 30

PROJECT 9. LEAF BREAKDOWN AND INVERTEBRATE COLONISATION IN STREAMS 32PROJECT 10. DISTRIBUTION OF SEEDS UNDER DISTURBANCE IN THE HERMITAGE OF BRAID 34

CODE OF PRACTICE FOR FIELD STUDIES 36GENERAL BEHAVIOUR 36YOUR RESPONSIBILITIES FOR SAFETY 36SAFETY PRECAUTIONS APPLYING TO ALL FIELD TRIPS 37CLOTHING,FOOTWEAR &SAFETY GEAR 37OCCUPATIONAL DISEASES 38EMERGENCY PROCEDURES: FIRST AID 38EMERGENCY PROCEDURES: WHEN LOST 39EXPOSURE (HYPOTHERMIA) 40GOING INTO THE FIELD ALONE 40

AFEW GUIDELINES ON EXPERIMENTAL DESIGN AND STATISTICAL ANALYSIS 41

GENERAL POINTS 41SAMPLING 41CONFOUNDING FACTORS AND EXPERIMENTAL BIAS 41INTERPRETATION 41DESCRIPTIVE STATISTICS 42

STATISTICS FOR HYPOTHESIS TESTING 43

APPENDIX 1. EXAMPLES OF FORMER EXAM PAPERS 46-58APPENDIX II. MAPS 59OWN WORK DECLARATION FORM 54


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Practical Projects

Practicals will be based in Ashworth teaching laboratory number 1 and the KB Centre Level 3 PC lab. Most ofthe practical work will take place in the Hermitage of Braid, a local Nature Reserve near to the King's Buildings.Practicals are held on Mondays from 2pm 5pm and are devoted to nine-week projects carried out in smallgroups. Statistics sessions will be run on some Mondays to support the project work see the timetable fordetails of dates. The practical work will be organised and run by demonstrators who will also mark your final

report.

In week 10 (Monday 21st November) parallel project presentations will be held from 2-5pm in: (i) the CrewAnnexe room 4 and (ii) room 302 of the Crew Building. Each project group will give a short (15 minute) verbalpresentation of the results and conclusions of the projects to colleagues and staff. Please check the WebCTAnnouncements or the Principles of Ecology notice board in the Crew Building during week 9 to find out whereeach project team will be making their presentation.

A hard copy of the project must be submitted to Helen McKeating, Undergraduate Office, room 211,

Crew Building by 12 noon on Friday 25th November. Projects should also be submitted via WebCT bythe same deadline.

NB. The "Practical Projects" section includes detailed instructions on how the final report should bewritten. Be sure to read them carefully.

Staff

Dr Gail Jackson,GeoSciences (Course Organiser). Room 217, Crew Building, 505436; [email protected]

Dr Patrick Walsh,Biological Sciences. Room 407, Ashworth Building, 505474; [email protected] Richard Ennos,Biological Sciences. Room 1.57, Ashworth Building, 505411; [email protected]

Dr Caroline Nichol, GeoSciences, The Crew Building, 507729; [email protected]

Prof Maurizio Mencuccini,GeoSciences, Room 216, The Crew Building: 505432; [email protected]

Dr Chris Ellis, The Royal Botanic Gardens Edinburgh 0131 248 2993; [email protected]

SYLVASylva was established in 1919, as part of the Universitys

Forestry and Natural Resources Department. It was publishedby the student society of the department and ran for 61 issuesuntil 1998. This year, the student science journal Sylva wasresurrected with the 2010 edition (No.63). As students ofecology and other natural sciences, you will find yourselvescompleting numerous pieces of work throughout the year on

various topics within this field of study. Why not submit your work for the nextedition of Sylva? This provides you with a great opportunity to get your workpublished in a peer-reviewed journal great for your own experience as well as

your CV. For more information, please contact us via e-mail:[email protected]. We look forward to your submissions,The Sylva Editorial Committee


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Timing

Lectures

Monday 0900-0950 Lecture Theatre 100, Joseph Black Building

Thursday 1000-1050 Lecture Theatre 201, Grant Institute

Friday 1305-1355 Lecture Theatre 201, Grant Institute

Locations

Lecture theatres are in the Joseph Black Building (Building 6, below) and Grant Institute (Building 9, below),labs are in the Ashworth laboratories (Building 13, below), and the Course Organiser and Secretary are locatedin the Crew Building (Building 5 below). Practical projects are in the Hermitage of Braid.

Important dates

Friday 25th Nov 2011 Deadline for practical report. Hand in by 12 noon to Helen McKeating,Undergraduate Office, room 211, Crew Building.

The exam date is not yet set. Check WebCT and/or Principles of Ecology notice board.

JCMB

Crew

N


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PlagiarismThe University has formal procedures for investigating and taking action on plagiarism, collusion (submitting apiece of work produced jointly with another student as though it were entirely your own work) and other forms ofcheating, at whatever stage of a candidates course, whether discovered before or after graduation(www.aaps.ed.ac.uk/regulations/Plagiarism/Intro.htm). If after investigation it is established that work submittedfor assessment has been plagiarised to a significant extent, that will be permanently noted on the candidatesrecord and zero marks will be awarded. The full text of the Universitys policy, and a statement of the steps

which the University may take in cases where a candidate uses, or is thought to have used, the work of anotherperson or persons in his/her work, is given in the Examination Regulations and Guidelines 2007-2008.Experience has shown that there are many more cases of poor scholarship (with consequent reduced marks)than intentions to deceive. Hence, the project report should be accompanied by a completed plagiarism form asat the back of this Handbook as a reminder and will ask you to confirm that you have:

Clearly referenced/listed all sources as appropriate Referenced and put in inverted commas all quoted text (from books, web, etc.) Given the sources of all pictures, figures, tables, data, etc. that are not your own Not made any use of the report(s) or essay(s) of any other student(s) either past or present Not sought or used the help of any external professional agencies for the work Acknowledged in appropriate places any help that you have received from others (e.g. fellow

students, technicians, statisticians, external sources)

Complied with any other plagiarism criteria specified in the course booklet

Copies of the form will be available from Helen McKeating so you dont have to tear pages out of this booklet.All project reports should be submitted electronically to Helen McKeating ([email protected]) and as ahard copy by the deadline set. The electronic copy will be passed through the plagiarism detection softwareused by the University: Turnitin.com

Appeals1) Course workIf you wish to appeal against a mark that you have been given for course work, you should contact the CourseOrganiser as soon as possible.

2) Exam

The procedure for appealing against a decision made by a Board of Examiners is set out in the UniversityDRPS and in the Programme of the College of Science and Engineering. You are strongly advised to consultyour Director of Studies before making an appeal, because he or she can approach the examiners on yourbehalf to investigate the circumstances, but this is not essential. You may appeal against a decision of theBoard of Examiners (a) on the grounds of substantial information which for good reason was not available to theexaminers when their decision was taken, or (b) on the grounds of alleged improper conduct of the examination

Staff-Student LiaisonA number of students will be elected to a Staff-Student Liaison Committee in the first few weeks of the first term.This committee will meet on two occasions to discuss all aspects of the course. The first meeting will be duringweek 6 of semester 1. The second meeting will be after the course has been completed, in week 6 or semester2. You should take your comments, criticisms, complaints and compliments to the student representatives. Allconstructive feedback is welcome. The staff are keen to take whatever action is reasonable and appropriate toensure student satisfaction with the course. In addition, a formal Course Questionnaire will be placed onWebCT at the end of the course. This is an integral part of the University's teaching quality assessment and it isimportant that all students respond.


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Students with Special NeedsAny student with special needs, e.g. dyslexia, may identify him/herself privately to the Course Organiser, so thatappropriate arrangements can be made. You may choose not to identify yourself, and this we respect.

Disabled StudentsWe welcome disabled students (including those with specific learning difficulties such as dyslexia) and areworking to make all our courses accessible. If you wish to talk to a member of academic staff about the course

requirements and your particular needs please contact Sarah McAllister (Manager of the GeoSciencesTeaching Organisation), GeoSciences, The Crew Building, Tel. 0131 650 4917, or email:[email protected].

You can also contact the Student Disability Service, 6 - 8 South College Street, Telephone 0131 650 6828 oremail [email protected] and an Advisor will be happy to meet with you. The Advisor can discusspossible adjustments and specific examination arrangements with you, assist you with an application forDisabled Students' Allowance, give you information about available technology and personal assistance such asnote takers, proof readers or dyslexia tutors, and prepare a Learning Profile for your School which outlinesrecommended adjustments. You will be expected to provide the Student Disability Service with evidence ofdisability - either a letter from your GP or specialist, or evidence of specific learning difficulty. For dyslexia ordyspraxia this evidence must be a recent Chartered Educational Psychologist's assessment. If you do not havethis, the Disability Office can put you in touch with an independent Educational Psychologist.

Further informationFurther class information, including provisional marks for the practical project reports, will be posted on WebCTand on the Principles of Ecology notice board (opposite the Undergraduate Office in the Crew Building, room211). Announcements may also be made from time to time by email. Please check your email and WebCTfrequently.

FeedbackFeedback on the various component of the course will be provided in the following ways:

Project presentations:Immediately after the presentation has finished the member of staff supervising the presentations will give aninitial response to the work and the quality of the presentation. In addition the presentations will be assessed byyour peers. Each student audience member will be asked to fill in a tick box sheet assessing the variousstrengths and weaknesses of the presentation. Written constructive comments will also be requested. Thesesheets will be collated by the project demonstrator, who will pass them to the Course Organiser to mount onWebCT. This will be done as quickly as possible, so they can be used to inform the project write-up.

Project reports:Your project demonstrators will mark your practical report. The demonstrator will each provide detailed writtenfeedback on each report. If you feel this is unclear or insufficient, in the first instance please approach yourdemonstrator for clarification and if you are still unclear, please contact the course organiser.

Exam feedback:The examination will occur sometime in December. In January a feedback session will be organised when

students are able to look at their exam paper and ask the lecturers any questions they may have. The examscripts cannot be taken from the room.

Course ChangesLast year the project hand-in date was set for two days after the project presentation session. In response tocomments made on Course Evaluation forms the hand-in date this year has been set for four days after theproject presentation date.


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Book List

Textbooks provide essential background reading and backup for your lecture notes and course handouts.There is no single book list for this course, nor is there any single book which is adequate as a 'course text'.However, we recommend Begon, M., Townsend, C. R. & Harper, J. L.(2006) Ecology(4th edn.) as the bestand most up-to-date Ecology text book available.

Each member of staff contributing to the course will provide an additional reading list including books andjournal material. Problems can quickly arise with a large class and limited library resources - please do nothoard books. Essential texts will be put onto the Temporary Reserve shelf in the Darwin Library.

The following are generally useful as sources of first reference on many topics. They cost 20-35 each.

Begon, M., Townsend, C. R. & Harper, J. L. (2006). Ecology (4th edn). Blackwell Science, Oxford. (Therecommended text for this course)

Townsend, C.R., Begon, M. and Harper, J.L. (2006). Essentials of Ecology (2nd

Edition). Blackwell Publishing.(Highly recommended).

Colinvaux, P. (1993). Ecology 2. Wiley, New York. (Readable and very good on some aspects)

Krebs, C. J. (1994 & 2001). Ecology. (4th & 5th edns). Harper Collins, New York. (Good on animalpopulations)

Ricklefs, R. E. & Miller, G. L. (1999). Ecology. (4th edn). Freeman, New York.

The following will be useful for particular parts of the course:

Patrick Walshs lectures: Animal ecophysiology

Willmer, P, Stone, G. & Johnston, I. (2004). Environmental Physiology of Animals. WileyBlackwell

Schmidt-Nielsen, K. (1984). Scaling: why is animal size so important? Cambridge University Press,Cambridge.

Eckert. Animal Physiology.

Caroline Nichols lectures: Plant ecophysiology

Taiz, L. & Zeiger, E. (2002). Plant Physiology(3rd edn). Sunderland, Mass.

Larcher, W. (2003). Physiological Plant Physiology(4th edn). Springer, Berlin

Schulze, E. D., Beck, E., & Mller-Hohenstein, K. (2005). Plant Ecology. Berlin/Heidelberg: Springer.

Chris Ellis lectures: The ecological niche

Tokeshi, M. (1999) Species Coexistence. Blackwell Science, Oxford.

Chase & Liebold (2003) Ecological Niches. University of Chicago Press, Chicago.

Krebs (2001) Ecology. Benjamin Cummings, San Francisco.

Gail Jacksons lectures: Vegetation history and succession

Ingrouille, M. (1995). Historical Ecology of the British Flora. Chapman & Hall, London.


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Maurizio Mencuccinis lectures: Changing abundance and distribution

E. I. Newman (2000). Applied Ecology and Environmental Management. Blackwell Science.

The European Nitrogen Assessment. Sources, Effects and Policy Perspectives. Edited by M Sutton et al., 2011.Cambridge University Press.

Richard Ennos statistics sessions and the practical project:

Fowler, J. Cohen, L. & Jarvis, P. (1998) Practical Statistics for Field Biology. 2nd Edition. John Wiley,Chichester.

Ennos, R. (2007) Statistical and Data Handling Skills in Biology. Pearson, Harlow.

Grafen, A & Hails, R (2002) Modern statistics for the life sciences. Oxford University Press, Oxford. 22.99

Sokal, R. R. & Rohlf, F. J. (1969) Biometry. Freeman, San Fransisco.

Ruxton, G. D. & Colegrave, N. (2006) Experimental Design for the Life Sciences. 2nd Edition. Oxford University

Press, Oxford.

Some more general books worth reading:

The Ages of Gaia by James Lovelock

Guns, Germs and Steel by Jared Diamond

The voyage of the Beagle by Charles Darwin


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PRACTICAL PROJECTSThe practical projects will be selected from the following list. No more than 12 people will be allowed to do anyone project and projects with fewer than 3 people will be cancelled. Groups containing 7 or more people will besplit into 2 groups. Please select your choice of project in WebCT.

1. The effect of gorse burning on the carbon stock of Blackford Hill2. Germination and establishment of gorse on Blackford Hill

3. Natural regeneration of trees in Hermitage Wood4. Importance of epilithic algae as food for stream invertebrates5. Variation in the abundance of tar spot infection on sycamore leaves6. Distribution of snails in woodland leaf litter7. Relationship between growth form and habitat in bryophytes8. Distribution and diversity of species in relation to rabbit grazing on Blackford Hill9. Leaf breakdown and invertebrate colonisation in streams10. Distribution of seeds under disturbance in the Hermitage of Braid

Preparing Practical Project Reports

Reports on practical work serve several functions:

1. Practice in scientific writing of the style found in research journals, i.e. concise and exact2. Practice in describing and illustrating methods, results and analyses clearly and unambiguously3. Providing notes for later revision to remind you about the exercise4. Enabling the Course Organiser to ensure that you have understood the exercise, and to contribute a

mark for your continuous assessment

Any report on practical scientific work should be divided into the following main sections which must be strictlyadhered to, though further division into sub-sections may be appropriate. This system (with only minorvariations) is used by nearly all scientific journals. Marks will be given separatelyfor each section of the report.

1. IntroductionThis should clearly state the aims of the exercise, and provide the background information necessary tointroduce the topic and explain the purpose of the exercise. You will need to refer to published work of a similarnature in order to set the context for your research. Cite references. By the end of the Introduction your readershould know what the project is about, what questions you are going to answer, what approach you are going totake and why those questions are important and interesting.

2. MethodsConcise descriptions (with diagrams if necessary) of the Study Area, the Materials and the Methodsused.These should be adequate to enable a reader to know precisely what you did and to enable him/her to repeatthe exercise exactly if he/she so wishes. Describe the conditions under which experiments were carried out,noting any circumstances which could conceivably alter your results or their interpretation. Do not

include trivial information that has no direct importance to the exercise.

3. ResultsA brief written descriptionof the results which draws particular attention to the most important and interestingfeatures of the data. The Results must be descriptivebut must NOT include any "discussion", "opinions" or"interpretation" of the observations; give only a factual account of what you actually observed. Thedescription must refer to data in numbered tables, graphs, and figures presented separately.

You will not yet have done much statistics, but you are expected to be able to demonstrate that your results aremeaningful and do not just represent chance events or random sampling error. Discuss the analysis of resultswith the demonstrators and staff. You should, at least by the end of this year, understand the statistical testingof hypotheses, and know how to use chi-squared, correlation, regression and t-tests where appropriate. If youknow how to use Minitab for analysing your data, then do so. If you do not feel confident of data analysis youshould discuss methods with the demonstrators.


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Style of writingUse the style of writing that you see in the scientific journals. Avoid unnecessary jargon. Make sentences clearand concise. Avoid a journalistic style or flowery language which tends to overstate the case and exaggeratewith metaphors. Your reader wants to get the maximum precise information for minimal effort; she/he is notreading just for idle entertainment.There is no word limit but, above all, be brief and concise. Exclude all irrelevant or trivial material. Include allessential material that may influence the interpretation of your results. Use the minimum words compatible with

including all the essential information. You should clearly separate indisputable fact (Results) from yoursubjective interpretation of those facts (Discussion). Give sufficient discussion to demonstrate that youunderstand the purpose of the exercise and the full significance of the results

MarkingSee the timetable for hand-in deadlines. Late submission of the report will result in penalties. Extenuatingcircumstances will only be considered if supported by a letter from your Director of Studies.With group projects it is inevitable that the methods and data tables will have a lot in common. Please note that,for assessment purposes, the Introduction, descriptions of Results and Discussion sections must be entirelyyour own work. Plagiarism is a serious offence. Please do not lend your report to other team members, asthis encourages plagiarism and can risk your implication in any plagiarism case that arises.

See the section on Plagiarism

The markers will be guided by a form when marking your work. You should use this form as a guide to writingthe report if you want to score high marks.

Project mark sheet

0 1 2 3 4 5

Title Informative but concise

Introduction Statement of objectives

Background information necessary to set the scene

Methods Site descriptionMaterials used (where this is critical to the method)

Methods described adequately

Results Statement summarising the main features of the data

Use of tables, graphs and figures

Self-explanatory legend to tables, graphs and figures

Assessment of errors

Statistical validation of results

Discussion Interpretation of the results

Clear statement of conclusions

Comparison of results with expectations/published theories

Discussion of practical consequences of conclusions

Criticism of experimental design

Suggestions for further study

References Adequate use of literatureCorrect citation in text

Correct listing at end of report

Overallpresentation Concise style of writing

Neatness

Avoidance of trivial detail

Final mark (NB. This is nota simple mean of the above marks)


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Verbal Presentation of Practicals

At the end of the project each group will be asked to make a short verbal presentation of its findings to thelecturers and to the rest of the class. You will need to prepare a 15 minute talk and consider how you willdisplay the results. Every member of the group should give a short section of the talk but all members of the

group should be prepared to answer questions concerning any aspect of the project. These presentations willbe assessed by your peers.

SYNOPSES OF PRACTICAL PROJECTS

Project 1. The effect of gorse burning on the carbon stock of Blackford Hill

IntroductionGorse (Ulex europaeus) is a spiny bush, and is a member of the pea family (subfamily Fabaceae). It is verywell adapted to stand-replacing fires, and is highly flammable. The plant grows rapidly with 1 year old stands

capable of producing around 1.2 tonnes of dry biomass per hectare per year. Stem diameters may increase byas much as 5 mm per year, with a height increase of 20 cm per year.

With such rapid growth, gorse is often managed by burning, usually on a 10-15 year cycle. This maintainshabitat for nesting birds, by diversifying the age structure. When stands are burnt, some proportion of the totalaboveground biomass is lost to the atmosphere as CO2. Stand rapidly recover from fires, as they have anumber of adaptations to exploit such disturbances: Seed pods are opened by fires, and there is strongevidence that germination is triggered by the heat.

This project aims to quantify the potential carbon losses from burnt gorse stands on Blackford Hill, and toexamine if managed stands represent a source or sink of carbon in the long term.

QuestionsConsider some of the following questions

1. How much carbon is stored in the existing gorse stands on Blackford Hill?2. What proportion of this carbon is lost on burning?3. Given the rapid regeneration of gorse stands after fires, does management by burning constitute a long

term source or sink of carbon?

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer will bedescriptive, try and express each question and answer in terms of a Null Hypothesis(H0).

For example, your H0might be that the long term emissions due to a gorse burning are zero, as the release is

balanced by new growth.

What sort of data do you need to collect in order to answer your question and test the null hypothesis? Will it bepossible to collect the required data?

Think about your question and the potential outcomes in terms of underlying ecological explanations.

MethodsFamiliarise yourself with the available habitat and decide on the null hypothesis you wish to examine. Thenidentify suitable sites for the study and devise an appropriate sampling scheme.

An estimate of the carbon content ot the gorse bushes can be made by calculating the biomass of the bushes.This is achieved by calculating the volume of the bush and multiplying by the dry density of the gorse. An

accurate measurement of the carbon lost on burning can be made by combustion in a furnace.


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You should consider how to obtain a representative sample of gorse bushes on Blackford Hill, the size of thesample, and how samples should be selected and distributed. How many bushes will be measured? How willbushes be selected? Ideally they should form an unbiased representation of the population (i.e. all the busheson Blackford Hill, about which we wish to draw conclusions from the data). You must also devise a way tostandardise your sampling procedure.

Points to Consider

1. If you estimate a parameter, such as dry density, how will you indicate the precision of your estimate?2. How do I proceed with sampling, and what do I need to measure?3. How do I choose which bushes to sample?4. How can I scale up from the bushes sampled to the whole of Blackford Hill?5. What is the appropriate plot size and what sort of sampling scheme should I follow?

What you will learn aboutMethods of estimating biomass and carbon storage of a habitatThe role of fire in the carbon cycleRegeneration of gorse patchesThe design of sampling surveys and experiments

The statistical analysis of results

Suggested EquipmentNotebooks and pencils30 m measuring tapesCallipersSecateursFoil traysPrecision balanceDrying ovenHeat proof mats

Methylated spiritsMatches

BibliographyEgunjobi, J. K. (1971). Ecosystem Processes in a Stand of Ulex Europaeus L.: I. Dry Matter Production, Litter

Fall and Efficiency of Solar Energy Utilization. Journal of Ecology, 59: 31 - 38Jacobson, M. Z. (2004). The short-term cooling but long-term global warming due to biomass burning. Journal

of Climate, 17: 2909 - 2926MAFF (1992). The heather and grass burning code. Available online.Zouhar, K. (2005). Ulex europaeus. In: Fire Effects Information System, [Online]. U.S. Department of

Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).

Available: www.fs.fed.us/database/feis/(2006, April 21).


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Project 2. Germination and establishment of gorse Ulex europaeaon Blackford Hill

IntroductionGorse Ulex europaeais a vigorous plant of waste land, but may also become a pernicious weed of agriculturalland. It occurs in patches over most of the Edinburgh hills. These patches are frequently burned, either

accidentally, deliberately, or maliciously. Following moderate fires gorse normally re-grows rapidly both fromseeds and from buds at the bases of the charred stems where litter has protected the stem bases from the heatof the fire. Does fire control gorse, or cause the gorse to spread and become even more of a pest?

Gorse, like several other plant species in fire-prone habitats may produce a very large bank of seeds lyingdormant in the soil. The establishment of large seed banks allows a plant not only to distribute itself spatiallybut also temporally. Large quantities of seeds are held in the soil and may germinate in the future followingdisturbance. A dense carpet of seedlings can often be seen soon after a fire, but what is it that breaks thedormancy and causes them to germinate so quickly? Fire severity describes the impact of a fire and theconsumption and heating of litter and soil can interact with seed bank size and viability to determine how wellgorse regenerates following burning.

QuestionsThere are several questions one might ask about the way gorse responds to fire.

1. Why do gorse seedlings appear to be so abundant just after a fire? Is the germination of seedsstimulated by fire? If so, then what feature of the fire is important to break the seed dormancy? How doseeds respond to raised temperatures and how does this vary with exposure time? Do seeds respondto the increase in light levels at the soil surface? Do the seeds actually germinate in large numberseverywhere, but are only conspicuous on the bare ground exposed by fire?

2. Can the history of gorse areas be determined by examining the depth and size of seed banks atdifferent levels within the soil? Is there evidence that areas currently covered in grass were oncedominated by gorse? How well are gorse seeds distributed in the soil, how does the viability of the soilseed bank change over time and what is likely to be the significance of this in relation to a fire event?

3. Do the young sprouts from burnt stem bases originate from a particular type of stem? What is thediameter (age) of stems which sprout most vigorously? Do the sprouts only come from stems protectedfrom the fire by a particular depth of litter? Could the regeneration of gorse be manipulated bycontrolled burning or gorse at a particular age, or in young stands with relatively little protective litter?

4. Are the patches of gorse expanding on the hills of Edinburgh? Can aerial photographs be used todetermine changes in the number and size of gorse patches over the last 40 years?

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer will bedescriptive, try and express each question and answer in terms of a Null Hypothesis(H0).

For example, your H0might be that germination success of gorse seeds from the litter layer is the same as thesuccess of older seeds buried deeper in the soil.

What sort of data do you need to collect in order to answer your question and test the null hypothesis? Will it bepossible to collect the required data?

Think about your question and the potential outcomes in terms of underlying ecological explanations. Is it possible to devise a survey of the distribution of gorse seedlings on Blackford Hill to test any of the aboveideas? Can you devise simple laboratory or glasshouse experiments to test whether fire stimulatesgermination? Can you recommend particular ways to control gorse by determining the age, or stage ofdevelopment of stands at which it should be burnt?

MethodsHaving decided on the hypotheses you wish to examine, devise an appropriate sampling scheme orexperimental setup. If sampling, you must identify suitable study locations. Will 'controls' will be necessaryagainst which to compare the effects of experimental treatments?


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Some simple designs could be: a) aim to get two columns of numbers representing some measured variable intwo situations. These might, for example, represent seedling density within several quadrats in both burned andunburned habitat. b) aim to get a table showing number of observations in different categories for one or moresituation. For example, the numbers of germinated and ungerminated seeds after exposure to differenttreatments. Many other designs are possible.

You must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Considering the example H0above: will a sampling unit be anindividual seed or a pot of seeds; will number of replicates be number of seeds or number of pots?; how willthe seeds be chosen - ideally they should be an unbiased representation of the population (i.e. all the seeds wewish to draw conclusions about from our results). You must also decide on a way to standardise your samplingprocedure.

Gorse seeds are fairly large and can be extracted from soil by sieving. Seedlings are easy to identify from thelarge size of the cotyledon leaves, though note that the early true leaves are quite different in appearance fromthose on mature plants.

You are unlikely to be able to do experiments on germination out of doors at this time of year. You could,

however, bring seeds or soil into the laboratory where some germination should occur in an incubator withinabout three or four weeks. To simulate the temperature effect of a passing fire, you could bake moist soil in amuffle furnace for a couple of minutes, or heat loose seeds in an oven at, say, 60 - 90 degrees.

Points to consider

1. As germination may take several weeks, any experiments on germination will have to be set up veryearly in the project - field observations can be done later. Germination trials should use more than 100seeds in each treatment.

2. How will you show that your results represent 'significant' effects and not just chance effects due tosampling error? If you have a Null hypothesis, can you test it statistically?

3. If you estimate a parameter such as average stem thickness, how will you indicate the precision of yourestimate?

4. Does the number of seedlings present at any site reflect the dispersal of seed, the survival of seed inthe soil once dispersed, the conditions stimulating germination, the survival of seedlings, or your abilityto find seedlings amongst other vegetation?

5. Young shoots of gorse are very palatable to rabbits and other herbivores.

What you will learn aboutSeed ecology and biology of germinationThe importance of microsite and seedling establishment in vegetation dynamicsEcology of fireExperimental designTesting of null hypotheses

Suggested Equipment

Note book, pencilQuadrat (10 x 10 cm, 25 x 25 cm, 50 x 50 cm or 1 x 1 m)Marker pen for labelling samplesSmall seed trays with potting compost, or Petri dishes and filter paper for germination testsMetal trays for use in muffle furnaceAluminium foil for enclosing Petri dishes in dark germination experimentSoil thermometer for measuring soil temperaturespH meter, buffers, sample tubes, deionised waterRange of soil sieves


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BibliographyFenner, M.(1985). Seed Ecology. Chapman & Hall, London.Rolston, M. P. & Talbot J. (1980). Soil temperature and regrowth of gorse burnt after treatment with

herbicides. New Zealand Journal of Experimental Agriculture, 8, 55-61.Ivens, G. W. (1983). The influence of temperature on germination of gorse (Ulex europaeus L.). Weed

Research, 23, 207-216.De Luis M., Baeza M. J., Raventos J. & Gonzalez-Hidalgo J. C. (2004): Fuel characteristics and fire behaviour

in mature Mediterranean gorse shrublands. International Journal of Wildland Fire, 13, 79-87.De Luis M., Garcia-Cano M. P., Cortina J. et al. (2001): Climatic trends, disturbances and short-term vegetation

dynamics in a Mediterranean shrubland. Forest Ecology and Management, 147, 25-37.Neary D. G., Klopatek C. C., DeBano L. F. & Ffolliott P. F. (1999): Fire effects on belowground sustainability: a

review and synthesis. Forest Ecology and Management, 122, 51-71.Legg, C. J. (1995). Heathland dynamics: a matter of scale. (Eds Thompson, D. B. A., Hester A. J. and Usher M.

B.) Heaths and Moorlands: Cultural Landscapes, 117-134. HMSO, Edinburgh.Lee W. G., Allen R. B. & Johnson P. N. (1986): Succession and dynamics of gorse (Ulex europaeus L.)

communities in the Dunedin Ecological District South Island, New Zealand. New Zealand Journal of Botany,24, 279-292.


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Project 3. Natural Regeneration in Hermitage Wood

IntroductionTrees may produce abundant seeds yet fail to reproduce themselves. Often, seedlings fail to develop in theshade of the parent trees such that when one tree falls over it will be replaced by a seedling of a different

species. Possible reasons for failure include (i) infertile seeds, (ii) seed predation, (iii) germination in anunfavourable microsite, (iv) predation of seedlings and browsing of saplings.

You will investigate regeneration of tree species in the wood and try to identify causes for failure ofregeneration. Species investigated should include oak, ash, beech, elm and sycamore. Attempt to identifypatterns of change in the species composition that would occur if the woodland were left unmanaged.

QuestionsConsider some of the following questions:

1. What is the age structure of the tree population? Is there any evidence of successful regeneration inthe past?

2. What is the density of seeds / nuts / fruits on the ground under different canopy species? What is thedensity of different seedling species under different canopy species?

3. Is seedling or sapling density related to the openness of the site? Seedling/sapling success may beinfluenced by available light intensity and competition with ground vegetation.

4. Can you determine which species is likely to replace any particular canopy tree should it fall down? Ifso, then knowing the numbers of each species of canopy tree at present, can you predict thecomposition of the woodland in the next generation?

Research ObjectivesDecide on specific question(s) that you would like to answer. Although part of your answer may be descriptive,try and express each question in the form of a testable Null Hypothesis(H0).

For example, your H0might be that seedling density under oak canopy does not differ from that under beechcanopy.

What sort of data do you need to collect in order to answer your question? Is it possible to devise a survey ofseeds, seedlings, saplings or trees to test any of the above ideas?


MethodsHaving decided on the hypotheses you wish to examine, find a suitable location for the study and devise anappropriate sampling scheme.

Some simple designs could be: a) aim to get two (or more) columns of numbers representing some measuredvariable in two (or more) situations. These might, for example, represent seedling density under different

canopy types. b) aim to get two columns of numbers representing two variables measured for each samplingunit. For example, the seedling density and % canopy cover at several sampling locations. Many other designsare possible.

You must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Considering the example H0above: if a sampling unit was to bea quadrat, what size should it be; how many quadrats would you sample under each canopy type; how will thequadrats be distributed under the canopy types - ideally they should be an unbiased representation of thepopulation (i.e. all the canopy area we wish to draw conclusions about from our results). You must also decideon a way to standardise your sampling procedure.

Tree girth, measured with girth tapes, can be used as a surrogate for age. Light intensity can be measured witha light meter.


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Points to consider


2. If you estimate a parameter such as average seedling density, how will you indicate the precision ofyour estimate?

3. How will you define a canopy tree, a sapling, a seedling? How will you identify the seedlings of trees(note that some may have lost all their leaves before you finish)? How will you identify the seeds ofdifferent tree species?

4. How will you obtain meaningful measures of the light environment in a wood when the light intensityoutside the wood is changing by the minute with changing cloud cover?

What you will learn about The identification of tree species Natural regeneration in forests Seed ecology Simple models of succession The design of sampling surveys and experiments The statistical analysis of results

Suggested Equipment Notebooks, pencils, hand lens 30 m measuring tapes Tree girth tapes 1 m x 1 m quadrats Light meter Soil sieves of a selection of sizes Books for tree identification

Bibliography

Cousens, J.(1974). An Introduction to Woodland Ecology. Oliver & Boyd, Edinburgh.Horn, H. S.(1975). Forest Succession. Scientific American, 232, 90 - 98Horn, H. S. (1975). Markovian properties of forest succession. Ecology and Evolution of Communities (ed.

Cody, M. L. & Diamond, J. M.) Harvard University Press, Cambridge, Mass.


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Project 4. The importance of epilithic algae for stream invertebrates

IntroductionThe surface of stones in many streams are covered with a layer of epilithic algae (epi = upon; lithos= stone).This algal layer is an important food source for many aquatic invertebrates that graze on stone surfaces. Any

environmental factors that influence the growth of algae, such as light, will also influence the distribution ofgrazing invertebrates. The Braid Burn, as it flows through the Hermitage, passes first through a narrow valleythat is well shaded by numerous tall trees and then through a much more open area.

This project aims to determine which invertebrate groups are commonly associated with epilithic algae and toinvestigate the effect of different light levels on algal growth and, consequently, the density and diversity ofinvertebrates using this resource.

QuestionsThere are many questions one might ask regarding epilithic algae and invertebrates, such as:

1. Is algal abundance and growth rate influenced by light levels?2. Which invertebrate groups are commonly associated with epilithic algae?3. Is abundance and composition of stream fauna related to algal abundance?4. Are there differences in stream fauna between shaded and open areas of the valley?5. How long does it take for algae and animals to recolonise bare surfaces?

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer will bedescriptive, try and express each question in the form of a testable Null Hypothesis(H0).

For example, your H0might be that algal growth rate is not related to light intensity.

What sort of data do you need to collect in order to answer your question? Will it be possible to collect therequired data? Is it possible to conduct a survey of epilithic algae and/or aquatic invertebrates to test any of the

above ideas? Can you devise simple experimental manipulations to examine the relationships betweensunlight, algae and invertebrates?


MethodsMany stream invertebrates that are commonly found on stone surfaces have well developed escape behavioursto avoid predators. Once disturbed, these animals usually move around to the underside of stones making itvirtually impossible to observe them feeding. It is possible, however, to sample these animals by placing a netdownstream of a target stone and gently rubbing all the animals off the entire stone and into the net. You maywant samples of the entire stream fauna, not just that on stone surfaces, and these can be collected by kicksampling. Many of the animals can be identified to a fairly detailed level whilst still alive; only a representativefew need to be preserved for identification. Respect the animals and return as many as possible to the stream.

The entire algal covering of a stone can be removed by scrubbing with a wire brush. By scrubbing a largenumber of stones and sampling them for animals over a long time period, you can observe the rate at whichalgae recolonise the stone and animals return to feed. Stones can also be 'transplanted' from shaded areas ofthe stream to more open areas, and vice versa. Measuring algal abundance directly is difficult. One way toestimate algal growth in various parts of the stream and over various time intervals is to put clean microscopeslides in the water and examine the intensity of 'colour' after some time.

Having decided on the hypotheses you wish to examine, find a suitable location for the study and devise anappropriate sampling scheme or experimental setup. Will 'controls' will be necessary against which to comparethe effects of experimental treatments?

Some simple designs could be: a) aim to get two (or more) columns of numbers representing some measured

variable in two (or more) situations. These might, for example, represent epilithic algal abundance in 'open' and'shaded' locations. b) aim to get two columns of numbers representing two variables measured for eachsampling unit. For example, the algal abundance and light intensity at several sampling locations. Many otherdesigns are also possible.


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You must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Considering the example H0 above: if a sampling unit was tobe a stone, should stone size be kept constant and what size should this be?; how many stones would yousample; how would the stones be distributed in the stream - ideally sampling units should be an unbiasedrepresentation of the population (i.e. all the stones we wish to draw conclusions about from our results). Youmust also decide on a way to standardise your sampling procedure?

Points to consider


2. If you estimate a parameter such as average algal abundance, how will you indicate the precision ofyour estimate?

3. How big is a stone? Very small stones are unstable and can get turned over even during small rainshowers. Very big stones can cause back problems. Experimental stones should all be of a similarsize, but you should also estimate the surface area of each one - particularly the upper surface. Howdo you measure surface area of an irregular shaped object?

4. How do you measure light intensity in two (or more) different places when it changes almost continuallywith cloud cover, time of day, etc.?

5. How long does it take for algae and animals to recolonise surfaces? During warm weather and long

hours of sunshine this can be very fast (1 day), in which case it may be necessary to sample at lessthan one-week intervals. In colder, dull weather recolonisation may be slow and you may need tomonitor over a few weeks.

6. Are all the animals in the stream likely to occur on stone surfaces or only some? How can you tellwhich ones?

7. How do you mark or label stones in a stream so that they can be located later?

HEALTH WARNING: The Braid Burn is not a very clean stream, so be careful to wash your hands thoroughlywith soap after working in the stream to avoid picking up any diseases. Health risks are minimal if simplehygiene procedures such as this are observed, so do not be put off working there.

Suggested EquipmentWellingtons or wadersWire brush to scrub stonesLight meterPond netPlastic bags to transport samples from the stream to the lab.White trays for sortingForcepsWide-mouthed pipettes, sample tubes, Petri dishesAlcohol for preservationMicroscopeKeys for identification

What you will learn aboutExperimental design and hypothesis testing.The importance of epilithic algae to stream communities.Identification and classification of aquatic invertebrates.The importance of light to stream communities.

BibliographyAllan, J. D.(1995). Stream Ecology. Chapman & Hall, London.Croft, P. S.(1986). A key to the major groups of British freshwater invertebrates. Field Studies6, 531-579.


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Project 5. Variation in the abundance of tar spot infection on sycamore leaves

IntroductionSycamore leaves at the end of the summer are commonly covered on their lower side with black 'tarspots'.These are caused by infection by the ascomycete fungus Rhytimsa acerinum. After leaf fall, the black spots

develop into sexual fruiting bodies or sclerotia. In April and May sexual ascospores are released from thesclerotia present in the leaf litter and infect expanding leaves of sycamore. The success of infection determinesthe number of tar spots seen the following autumn. Infection by R. acerinum is thought to hasten thesenescence of sycamore leaves so that infected leaves fall earlier than uninfected leaves. Wide variation isfound in the extent of infection between different areas, and between different trees within these areas.

Questions1. How is the extent of leaf spot infection affected by various factors? Some of these factors might be:

Extent of leaf litter retained beneath tree Height of leaves from the ground (source of spores). Amount of air pollution. Density of sycamore trees.

2. Is there a relationship between tar spot infection and time of leaf fall?3. Are there significant differences in infection between urban and rural sites?4. Are there significant differences in infection between different trees within the same site?

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer may bedescriptive, try and express each question in the form of a testable Null Hypothesis(H0). For example, your H0might be that number of tar spots per leaf in rural sites does not differ from that in urban sites.

What sort of data do you need to collect in order to answer your question? Will it be possible to collect therequired data?



Some simple sampling designs could be: a) aim to get two (or more) columns of numbers representing somemeasured variable in two (or more) situations. These might, for example, represent infection prevalence inseveral trees from both urban and rural sites. b) aim to get two columns of numbers representing two variablesmeasured for each sampling unit. For example, the infection prevalence and litter depth for several samplinglocations. Many other designs are possible.

You must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Considering the example H0 above: is a sampling unit a leaf, anarea of leaf, a tree?; how many leaves, areas, trees or locations will you sample?; how will samples bedistributed, which leaves on a tree or trees in a site will you sample? - ideally sampling units should be anunbiased representation of the population (i.e. all the leaves, trees etc. that we wish to draw conclusions aboutfrom our results). You must also decide on a way to standardise your sampling procedure.

You must decide on the most appropriate measure of tar spot infection - spot number, spot area,presence/absence of spots? Perhaps sample a few leaves first to get an idea of what is appropriate.


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Points to consider


2. If you estimate a parameter such as tar spot abundance or average leaf height, how will you indicatethe precision of your estimate?

3. Will your tar spot index take into account the size of the leaves?4. Are other factors likely to be associated with tar spot infection? Could the effect of other factors

confound the results of your study?5. How would premature falling of infected leaves affect your estimate of abundance?

What you will learn aboutFungal biologyFactors affecting the abundance and distribution of parasitic fungiAssessing biological variability and its causesEffects of fungal infection on plants.Experimental designStatistical analysis

Suggested EquipmentPlastic bagsIndelible pensMetre ruleQuadratsLong handled pruners for sampling leaves to 3m.

BibliographyLeith, I. D. & Fowler, D.(1987). Urban distribution of Rhytisma acerinum(Pers.) Fries (tar spot) on sycamore.

New Phytologis, 108, 175-181.Sutherland, W.J. (1996). Ecological census techniques: a handbook. Cambridge University Press,

Cambridge.


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Project 6. Distribution of snails in woodland leaf litter

IntroductionLand snails (Mollusca) are distributed across a diverse array of habitats in woodland sites. They are readilysampled in such habitats by sieving leaf litter that forms the major part of their diet. The abundance andspecies composition of land mollusc communities is dependent upon a number of environmental factors. Themost important of these appear to be the level of calcium available to the snails for building their shells, the

moisture level, and the degree of 'shelter' offered by the habitat. Certain species are more tolerant of lowcalcium levels while others may be more tolerant of low moisture levels, and these differences in preferencemay alter the species composition in different microhabitats. This project will be concerned with investigatingthe abundance and species composition of land snail communities within different microhabitats in theHermitage of Braid.

QuestionsTo what extent is the abundance and species composition of snail communities related to:

1. origin of leaf litter (oak, beech, ash leaves for instance?)2. pH of soil (related to calcium levels)3. degree of 'shelter'4. moisture levels

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer may bedescriptive, try and express each question in the form of a testable Null Hypothesis(H0).

For example, your H0might be that the abundance of a particular species of snail in holly litter does not differfrom that in oak litter.

What sort of data do you need to collect in order to answer your question and test the Null hypothesis? Will itbe possible to collect the required data?



Some simple sampling designs could be: a) aim to get two (or more) columns of numbers representing somemeasured variable in two (or more) situations. These might, for example, represent snail densities in severallitter samples from oak litter and holly litter. b) aim to get two columns of numbers representing two variablesmeasured for each sampling unit. For example, the snail density and soil moisture level at several samplinglocations. Many other designs are possible.

You must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Perhaps take a few preliminary samples to get an idea of what

is appropriate. Considering the example H0 above: would a sampling unit be a quadrat, or a given volume oflitter, or something else, and what size would the sampling unit be?; how many sampling units would yousample; how would the samples be distributed within the woodland - ideally sampling units should be anunbiased representation of the population (i.e. all the litter we wish to draw conclusions about from our results).You must also decide on a way to standardise your sampling procedure?

Snails can be extracted from litter samples in the lab using a combination of sieving and separating techniquestogether with manual searching and removal. Your demonstrator can advise further. Moisture content of soil orlitter can be determined by collecting material, weighing, drying and weighing again. Instruments are availablefor measuring relevant environmental variables such as Ph.


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Points to consider


2. If you estimate a parameter such as average abundance, how will you indicate the precision of yourestimate?

3. Ensure that you know how to identify species of snails. The common species are much smaller thanyou may imagine. The key given in the references is very good.

4. Is there going to be a problem with confounding factors? Will this interfere with the interpretation of theresults? e.g. are all holly trees situated on drier sites than oak trees?

5. How is abundance best measured?

What you will learn aboutMollusc diversity and classificationMollusc biology and ecologyFactors affecting species distributionSampling methodsExperimental designTesting of null hypotheses

Suggested EquipmentNote book, pencilHand lensNylon mesh bags (for collecting leaf litter)Oven (for drying leaf litter)Sieves of various sizes for sorting snailsBinocular microscopeKeys for identificationInstruments for measuring relevant environmental factors e.g. pH meter

BibliographyBoycott, A. E.(1934). The habitats of land mollusca in Britain. Journal of Ecology22, 1-38.

Cameron, R. A. D.(1973). Some woodland mollusc faunas from Southern England. Malacologia14, 355-370.

Kerney, M.P. & Cameron, R.A.D.(1996). Land snails of Britain and north-west Europe. HarperCollins, London.

Tattersfield, P.(1990). Terrestrial mollusc faunas from some South Pennine woodlands. Journal of Conchology33, 355-374.

Southwood, T.R.E & Henderson, P.A.(2000). Ecological methods(3rd

ed.). Blackwell Science.


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Project 7. Relationships between bryophyte growth form and habitat

IntroductionBryophytes (mosses and liverworts) exhibit a very diverse array of growth forms. These may be classified intothe following broad categories:

Cushions: erect shoots radiating up to form a compact dome Turfs: parallel erect shoots forming dense smooth surface Canopies: systems with a raised leafy canopy Mats: interwoven stems spreading horizontally over a surface Wefts: loosely intertwined shoots, often ascending

The growth form adopted by a bryophyte is likely to be closely tied to the ecology of that species. Some growthforms will be better adapted for competition, others for protection against desiccation, etc. For this reason wemay anticipate that there will be relationships within a community between the abundance of particular growthforms of bryophytes and particular habitats within an area. This project will be concerned with detecting suchassociations between growth habit and habitat for the community of bryophytes in the Hermitage of Braid.

QuestionsHow is the distribution of different growth habits in bryophytes related to particular characteristics of the habitat?Important characteristics of the habitat might include:

1. humidity2. light intensity3. inclination of substrate (vertical/ horizontal)4. nature of the substrate (rock ,soil, bark, etc.)

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer will bedescriptive, try and express each question in the form of a testable Null Hypothesis(H0). For example, your H0might be that cushion-forming bryophytes are equally abundant on open rocks and heavily shaded rocks. What

sort of data do you need to collect in order to answer your question and test the Null hypothesis? Will it bepossible to collect the required data?


MethodsFamiliarise yourself with the available habitat and decide on the hypotheses you wish to examine. Then identifysuitable sites for the study and devise an appropriate sampling scheme. Some simple sampling designs couldbe: a) aim to get two (or more) columns of numbers representing some measured variable in two (or more)situations. These might, for example, be measures of abundance of cushion forming bryophytes on open rocksand in heavy shade. b) aim to get two columns of numbers representing two variables measured for eachsampling unit. For example, the abundance of cushion forming bryophytes and light intensity at severalsampling locations. Many other designs are also possible.

You must consider the size and nature of individual sample units, the size of the sample and how samplesshould be distributed. Considering the example H0 above: would a sampling unit be a whole rock or a quadratplaced on the rocks, what size should the rocks or quadrats, respectively, be?; how many rocks or quadratswould you sample?; how would you choose which rocks to sample, how would they be distributed and, if usingquadrats, would you sample more than one quadrat from the same rock? - ideally sampling units should be anunbiased representation of the population (i.e. all the rocks we wish to draw conclusions about from our results).You must also decide on a way to standardise your sampling procedure?

Instruments are available for measuring relevant environmental variables such as light intensity.


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Points to consider


2. If you estimate a parameter such as average abundance, how will you indicate the precision of yourestimate?

3. What classification scheme is going to be used for growth form? To what extent will it be necessary toidentify the species involved? (Consider the extra information that could be gained). Microscopes and keyswill be needed for identification.

4. Is there going to be a problem with confounding factors? Will this prevent you drawing reliable conclusionsfrom the results? E.g. are all open habitats liable to heavy trampling while those in heavy shade areundisturbed?

5. How is abundance best measured? What scale of sampling unit is most appropriate?

What you will learn aboutBryophyte diversity and classificationBryophyte biology and ecologyFactors affecting distribution of speciesExperimental design

Testing of null hypotheses

Suggested EquipmentNote book, pencilHand lensPlastic bags (for collecting specimens)MicroscopeSlidesKeys for identificationInstruments for measuring relevant environmental factors-light meter?

BibliographyBirse, E. M.(1958). IV. Growth form distribution in a deciduous wood. Journal of Ecology46, 29-42.

Gimingham, C. H. & Birse, E. M.(1957). Ecological studies on the growth form of Bryophytes. I. Correlationsbetween growth form and habitat. Journal of Ecology45, 533-545.

Jahns, H.M. (1983). Collins guide to the ferns mosses and lichens of Britain and North and Central Europe.Collins, London.

Watson, E. V.(1968). British Mosses and Liverworts. Cambridge University Press, Cambridge.


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Project 8: Distribution and diversity of species in relation to rabbit grazing onBlackford Hill

IntroductionThe European rabbit (Oryctolagos cuniculus) has become so successful that is considered a pest in many

areas. They were introduced to the UK by the Normans in the 12th century to provide meat and fur. They liveon heathland, open meadow, grassland, woodland, the fringes of agricultural land and dry sandy soil, includingsand dunes, but they avoid coniferous forests. Rabbits eat the leaves of a wide range of vegetation includingagricultural crops, cereals, young tree and cabbages. In winter, they eat grasses, bulbs and bark. They re-ingest their faeces for nutritional benefit. Rabbits have a burrow system known as a warren, and tunnels can be1-2m long. They use regular trails, which they scent mark with faecal pellets.

Rabbit grazing affects the stature and composition of vegetation throughout the year and the size of populationcan influence the numbers of plant species in an area. Continuous grazing by large numbers of rabbits leads toan increase in ground cover in some species (e.g. Anthoxanthum odoratum and Rumex acetosella and adecrease in others (e.g. Festuca rubra and Trifolium repens). They can pose serious threats to sensitivehabitats, yet conversely, rabbit grazing is essentially for the maintenance of other threatened habitats such ascalcareous grasslands and many invertebrate species are dependent on rabbit grazing for the maintenance of

their habitats, such as the large blue butterfly (Maculinea arion).

PollutionThere are several questions one might ask about the effects of rabbit grazing on the distribution and abundanceof species.

1. Do rabbits increase or decrease plant species richness on Blackford Hill?2. What are the characteristics of plant species that occur only near to or only far from rabbit burrows?3. Are some species particularly associated with soil distrurbance caused by rabbits?

Additional questions can be posed of invertebrate distribution and abundance.

Research Objectives

Decide on a specific question or questions that you would like to answer. Although part of your answer may bedescriptive, try and express each question or prediction in the form of a testable Null Hypothesis (H0). Forexample, your H0might be that grazing by rabbits does not affect the distribution of vascular plant species onBlackford Hill.

What sort of data do you need to collect in order to answer your question? Will it be possible to collect therequired data? How will you devise a method of surveying the the numbers of rabbits and/or distribution ofrabbit burrows on Blackford Hill? Can you find comparable areas of grassland, where the vegetation is heavilygrazed and lightly grazed, for example?


Methods

Having decided on the hypothesis you wish to examine, devise an appropriate sampling scheme orexperimental setup. If sampling, you must identify suitable study locations. Will 'controls' be necessary againstwhich to compare the effects of experimental treatments? Some simple designs could be:

a) aim to get two columns of numbers representing some measured variable in two situations. These might,for example, represent species diversity within several quadrats in both grazed and ungrazed habitat.

b) aim to get a table showing a number of observations in different categories for one or more situations. Forexample, the percentage cover of selected species in areas of heavy grazing, light grazing, and rabbitscrapes. Many other designs are possible.


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Identifying lichensYou must consider the size and nature of individual sample units, the size of the sample and how samples orexperimental treatments should be distributed. Considering the example H0above: will the sampling unit be aspecies or a quadrat? How will the size of quadrat be chosen? How will they be distributed? Ideally theyshould collect an unbiased representation of the population (i.e. all the vegetation types you wish to drawconclusions about from our results). You must also decide on a way to standardise your sampling procedure.

Points to consider

1. You will initially spend a great deal of time determining how the rabbits are distributed on the hill and itmay be two or three weeks before you begin to collect vegetation data. Practice your identification skillsin these weeks.

2. How will you show that your results represent 'significant' effects and not just chance effects due to asampling error? If you have a Null hypothesis, can you test it statistically?

3. If you estimate a parameter such as numbers of rabbits, how will you indicate the precision of yourestimate?

4. Does the number of species recorded reflect the dispersal of species on the hill, the resistance ofspecies to grazing, the variation in conditions on different parts of the hill (altitude, aspect, angle ofslope), or your ability to identify species?

What you will learn about Grassland species diversity and identification The effect of grazing on individual species The grazing behaviour of rabbits Ecology of grazing Experimental design Testing of null hypothesis

Suggested equipmentNote book, pencilQuadrats (10 x 10 cm, 25 x 25 cm, 50 x 50 cm, or 1 x 1 m)

Sample bagsMarker pen for labelling samplesidentification keys

Bibliography

Bullock, J.M., Franklin, J., Stevenson, M.J., Silvertown, J., Coulson, S.J., Gregory, S.J. & Tofts, R.(2001).

A plant trait analysis of responses to grazing in a long term experiment. Journal of Applied Ecology, 38,

253-267.

Kolb, H. H.(1991). Use of burrows and movements of wild rabbits (Oryctolagus cuniculus) in an area of hill

grazing and forestry. Journal of Applied Ecology, 28, 892-905.

Crawley, M. J. (1990). Rabbit grazing, plant competition and seedling recruitment in acid grassland. Journal of

Applied Ecology, 27, 803-820.

Myers, K. & Poole, W.E.(1963). A study of the biology of the wild rabbit, Oryctolagus cuniculus(L.), in

confined populations. Journal of Ecology, 51, 435-451.

Identification keys

Rose, F.(2006) The Wild Flower Key. How to identify wild flowers and shrubs in Britain and Ireland (revised

edition). Penguin Books, London

Chinery, M.(1993). Collins Field Guide: Insects of Britain and Northern Europe (3rd

Edition). Harper Collins

Publishers, London

Fitter, R., Fitter, A. & Farrer, A. (1984). Collins Pocket Guide: Grasses, Sedges, Rushes and Ferns of Britain

and Northern Europe. Collins, London

Hubbard, C.E. (1984). Grasses.A guide to their structure, identification, uses and distribution in the British Isles

(3rd

Edition). Penguin Books, London


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Project 9: Leaf Breakdown and invertebrate colonisation in streams

IntroductionRiparian vegetation (i.e. plant communities on the fringes and adjacent to water bodies), through its input intostreams, provides an important habitat and food source for aquatic invertebrates. Leaves provide little

nutritional value when freshly fallen, but as they are being broken down by bacteria and fungi, they are quicklycolonized by invertebrates. However, not all kinds of leaves break down at the same rate, some being brokendown more rapidly (e.g. Fraxinus excelsior) than others (e.g. Salix spp.) and not all leaves have the samenutritional value and palatability.

This project aims to investigate the relationship between the abundance, richness, diversity and distribution ofaquatic invertebrates within the Braid Burn, and the presence/absence and type of leaves in this stream.

You will be sampling aquatic invertebrates in different areas of the Braid Burn (e.g. under forest cover or openareas; in areas where leaves accumulate or areas without leaves), as well as in leaf packs (bags containingleaves from different tree species) submerged in the stream and recovered every week for analysis.

QuestionsMany questions may be asked regarding leaf breakdown, leaf palatability and invertebrate diversity anddistribution in the stream, such as:

1. Are the abundance, richness and diversity of aquatic invertebrates affected by the presence of leafpacks in the stream? Why?

2. Are different species of aquatic invertebrates associated with different kinds of leaves (from differenttree species)? Why?

3. How long does it take for invertebrates to colonize leaf packs and does the diversity and composition ofinvertebrates evolve over time?

4. Which leaf species are broken down more rapidly? How can differences in breakdown rate beexplained?

5. Does light, temperature or flow velocity influence invertebrate distribution within the stream? How?

Research ObjectivesDecide on a specific question or questions that you would like to answer. Although part of your answer will bedescriptive, try and express each question or prediction in the form of a testable Null Hypothesis (H0). Forexample, your H0might be: "there is no difference in invertebrate diversity between leaf packs containing leavesfrom different tree species". Your alternative hypothesis H1would then be: "there is a difference in invertebratediversity between leaf packs containing leaves from different tree species".

What sort of data do you need to collect in order to answer your question? Will it be possible to collect therequired data during the period dedicated to the project?

MethodsMost leaves in streams gather in small groups called leaf packs. In order to stimulate this process, you will build

mesh bags (e.g. 1 cm x 1 cm mesh), fill them with leaves and place them in the stream. You should choose thetree species you want to investigate and pick up fresh leaves collected from several trees to avoid damagingone particular tree. Place the leaves in comparable mesh bags (e.g. 20 cm x 20 cm) and secure them to thestream bed so that they don't wash away easily. You should choose carefully the number of bags you want toput in the stream (e.g. you should be able to recover each week 2 or 3 replicates for each kind of leaf), the sizeof the bags and the quantity of leaves, and the area of the stream where you want to place them (lookingcarefully at flow velocity, natural obstacles, light intensity, etc.).

Each week, collect a given number of mesh bags with a net held downstream to catch any invertebrates thatmay have been disturbed into the water column. Place these bags (and the content of the nets) into largeplastic bags for transportation back to the laboratory. To count and identify invertebrates present in each leafpack, place small amounts of leaves in white trays with 1 or 2 cm of tap water. Use spoons, brushes, andforceps to separate invertebrates from the leaves. Invertebrates should be separated from the rest of the

material as soon as possible after retrieval from the stream, as sorting and identifying living animals is easier.Invertebrates collected can be stored in small vials with 70% ethanol, and should be counted and identified tofamily level. Most of the animals can be easily identified using a microscope and relevant keys (e.g. Croft,1986).


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Points to considerHaving decided on the hypotheses you wish to examine, find a suitable location for the study and devise anappropriate sampling scheme. How many leak packs will you need? How many times and how often will youcollect them? Where in the stream are you going to place them? Where are you going to do your kicksampling? Which method will you choose? Which parameters can you measure to describe your site. (e.g.temperature, water pH, flow velocity). How will you show that your results represent 'significant' effects and notjust chance effects due to sampling error? If you have a Null hypothesis, can you test it statistically? What kindof test can you use and why?

HEALTH WARNING: The Braid Burn is not a very clean stream, so be careful to wash your hands thoroughlywith soap after working in the stream to avoid picking up any diseases. Health risks are minimal if simplehygiene procedures such as this are observed, so do not be put off working there.

Suggested equipmentWellingtons or wadersPond netPlastic bags to transport samples from the stream to the lab.Wire or plastic meshWire or string

SievesWhite trays for sortingForcepsSample tubes, Petri dishesLabelsAlcohol for preservationMicroscope and x10 lensesKeys for identification of invertebrates and treesThermometerpH-meterLight-meter

What you will learn aboutThe importance of terrestrial inputs to stream communities and the implications for stream management.The factors influencing the distribution of invertebrates in the stream.Identification and classification of aquatic invertebrates.Identification of trees.Experimental design, hypothesis testing and report writing.

BibliographyBooks:

Allan, J. D.(1995). Stream Ecology: Structure and function of running waters. Chapman & Hall, London. 388 p.

Croft, P. S. (1986). A key to the major groups of British freshwater invertebrates. Field Studies Council,Taunton. 48 p.

Articles:

Parkyn, S. M., Winterbourn, M. J. (1997). Leaf breakdown and colonisation by invertebrates in a headwaterstream: comparison of native and introduced tree species. New Zealand Journal of Marine and FreshwaterResearch31: 301 - 312.

Richardson, J. S., Shaughnessy, C. R., Harrison, P. G. (2004). Litter breakdown and invertebrate associationwith three types of leaves in a temperate rainforest stream. Archiv fr Hydrobiologie159(3): 309-325.


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Project 10: Distribution of seeds under disturbance in the Hermitage of Braid

IntroductionNatural regeneration is one of the most common ways for trees to seed in natural woodlands and forests undercontinuous cover management schemes. In order for natural regeneration to occur, an appropriate seedbed is

needed on the forest floor, in combination with appropriate environmental conditions. However, naturaldisturbance (e.g. birds and animals) or human disturbances (e.g. thinning and pruning) can affect of how treesdisperse their seeds and the available seedbed for natural regeneration.

This project aims to quantify the effect of disturbance and explain possible reasons for the observed distributionof seeds in the Hermitage of Braid.

QuestionsThere are many questions one might ask. For example:

1. How does the distribution of seeds determined by "mother" tree and how does seed abundance changewith distance?

2. How does anthropogenic disturbance (e.g. thinning) affect the distribution the seeds?3. Is wind or the topography the most important factor controlling distribution patterns?

Research ObjectivesDecide on specific question(s) that you would like to answer. Although part of your answer may be descriptive,try and express each question or prediction in the form of a testable Null Hypothesis(H0).

For example, your H0might be that intensive management regimes increase the distribution of seeds from theseed productive trees.

What sort of data do you need to collect in order to answer your question? What should be the best way tocollect the data?

MethodsHaving decided the questions you are interested to answer and forming the major hypothesis you would like totest, choosing the appropriate site location is the next step. Sites must be chosen according to their disturbancehistory. Such information is available either in a management plan or by interviewing the local rangers. Youmight need to identify stands where animal activities are known to be present or stands where otheranthropogenic disturbance is taking place (e.g. dog walking).

Next, the appropriate sampling scheme should be selected considering always the main aim of the project,which is to investigate the distribution of seeds around a "mother" tree, taking under consideration thetopography of the site. Then a standardised sampling scheme should be chosen and applied throughout theduration of fieldwork. You need to consider: i) if you need to measure the numbers of seeds in total orseparately by species, ii) to measure the distance from a reference tree or iii) how far to sample and in whichdirection.

The final product should be a dataset of seeds numbers in groups by species and disturbance type. Thenstatistical testing might be needed to test the significance between the means of your samples in order toaccept or reject the hypothesis that heavily managed stands have an effect on the distribution of the seeds, andthus affect the possibilities for natural regeneration. Appropriate graph and chart presentation would beessential.


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Points to consider.1. What is the main hypothesis?2. How do I proceed with the design of the sampling and what are the variables I need to measure?3. Which are the criteria for choosing the appropriate stands to sample?4. How do I choose the "mother" tree?5. Which is the appropriate plot size and what sort of sampling scheme should I follow?6. What statistical analysis should I perform and how to present the results?

What you will learn aboutIdentifying trees and seedsDesigning of sampling scheme to fulfil certain needsSampling designPerforming basic statistical analysisPresenting results

Suggested equipmentNote book and pencilMeasuring tape

Books for tree and seed identificationSticks and tape for sampling plotsSmall quadrats

BibliographyFenner, M.(1985). Seed Ecology. Chapman & Hall, London.Mayer, A. M. & Poljakov-Mayber, A.(1975). The Germination of Seeds(2

ndEd.). Pergamon Press, London.


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Safety precautions applying to all field trips

Wear clothing and footwear suitable for the weather, the activity and terrain. You will not be allowed toparticipate in a field course if you are ill-equipped for the conditions. Section A4 gives general guidelines, andspecific activities may require additional items.

Stay with your group,except by clear arrangement with the course leader.

Meet as arranged at the completion of work. In particular, do not make your own way back home (or tolodgings, etc.) without express permission of the course leader.

Report illness, accident, incident affecting safety, or misbehaviour to the course leader.

Do not endanger yourself or others by fooling around; for example, by running down steep slopes, rollingstones down slopes, throwing objects around, flicking tree branches.

Never smoke or light fires in forests or on moorland. Conditions for the spread of undergrowth fires may bepresent in any season.

Show extra care on cliffs and steep slopes. Gusty winds can blow you over. Cliff edges may be crumbling.

Do not dislodge loose rocks. Grass verges may be very slippery.

Do not incur additional risksby e.g. climbing cliffs, walking on slippery rocks, or wading along rivers, unlessthese activities have been approved as an essential part of the course.

Do not touch machinery in forests, farms, factories, etc. unless it is a specific requirement of the course. Inparticular, you will never be allowed to use a chain saw without thorough training and specific permission.

Use potentially dangerous apparatus with care, and with due regard to the operating instructions.

Take care along roads, when you need to work beside the road (e.g. for surveying, sampling vegetation).Walk on the right hand side (i.e. facing oncoming traffic) and remember that a group walking along a road

represents a specific hazard. You are not allowed along motorways or railways.

Take care when leaving buses. Remember that this is dangerous when the bus stops at the roadside.

Familiarise yourselfwith the Forestry Safety Council leaflet 34: First Aid

Make sureyou carry the Personal First Aid and Emergency Kit described below

Clothing, footwear & safety gear

Minimum clothing: loose-fitting trousers, shirt, warm sweater, cagoul, warm socks.

Desirable additional clothing: Warm headgear (in addition to the hood of a cagoul), cagoul, waterproofovertrousers, extra sweater. (Remember that several thin layers are better than one heavy layer of clothing).Your cagoul should be brightly coloured.

Footwear: nailed boots or strong boots with rubber mountaineering soles, wear wellingtons only when shallowwading is anticipated.

Do not wear: shoes (as opposed to boots) especially sports shoes or light casual or dress shoes; a dress;jeans (highly undesirable as they absorb moisture and can cause exposure when wet and subjected to a coldwind).

Wear a safety helmetwhen this is provided for your safety when there is a danger from falling rocks or trees,or a danger of falling.


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Personal First Aid and emergency kit. You are advised to carry with you, as a matter of course on all fieldtrips, the following items in a plastic bag:

a loud whistle; the Forestry Safety Council Leaflet No.34: First Aid; 1 adhesive dressing;

1 plain lint wound dressing; 2 antiseptic wipes; Safety matches.

The best policy is to keep this kit in a cagoul

principles of ecology.pdf

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