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REGENERATION DYNAMICS OF

FOREST TREES IN PERMANENT FIELD

LABORATORY AREAS AT MT.

MAKILING FOREST RESERVE

by

A.C. Luna, N.M. Pampolina & B.A. Punzalan

PFLAs in Mt. Makiling Forest Reserve

Established as venues for gathering data in order that the dynamics of forest ecosystem may be better understood

Gathered data from PFLAs will help the College become more effective in forest and natural resources instruction, research and management

PFLAs is a realization of the long-term objective of the College to use MFR as a training laboratory for graduates of forest and natural resources management

As envisioned, appropriate laboratory exercises will be conducted in these PFLAs

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Mt Makiling

Forest ReserveLuzon Island

4,244 hectares

Established 1910

Average annual rainfall of 239.7 cm

Temperature is 25.5oC to 27.5oC

Climate is tropical monsoon, two pronounced seasons, wet from May to December and dry from January to April.

Soil is clay loam, derived from basalt and andesite

• located 14°08 N, 121° 11 E

• 65 km southeast of M.M.

• highest peak at 1090 m asl

Mt. Makiling Forest

Reserve

Molawin

Saran

DampalitPansol

Tigbi

Puting

Lupa

Sipit

Maitim

Cambantoc

PangawKabaong

Salusan

PFLA 1

PFLA 2

PFLA 3

MCME

CFNR Admin.

Location of Permanent Field Laboratory Area (PFLA) in MFR

CFNR Campus

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Objectives of the project

General Objective:

Monitor the forest dynamics of PFLA in Mt. Makiling Forest Reserve, including the demographic characterization of major component tree species.

Specific Objectives:

Characterize the structure, composition, and mechanisms that explain the species diversity in PFLA.

Analyze regeneration traits of major component tree species by studying survival of wildlings and sapling.

Evaluate micro-environmental factors that affects regeneration and successional patterns in PFLA; and

Recommends ecological and silvicultural approaches for sustainable management of PFLA.

Materials and Methods

Site selection and identification of main component trees

Criteria: maturity of the stand, topography, elevation, and accessibility

Main component trees are those of which importance values (IV) belongs to top ten highest values

Species were already matured and produced regenerations in the area

Described in term of species, height, diameter at breast height (DBH), plant diversity, and phenology (eg. flowering and fruiting)

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Establishments of sampling plots and regeneration plots

A permanent plot of three 1-ha was surveyed and gridded

For the investigation on seedling demography, 12 regeneration quadrats (2m x 3m) were established, seedlings were identified and measured for height and root collar diameter

Succession of regenerants on the forest floor was monitored, including their growth and survival

Comparative description of the PFLAs in MFR

PLFA Size of

Initial

Plot

Watersh

ed Area

Toporaphy Elevation

(m asl)

Vegetation Accessibility

1 1 ha. Molawin Steep slope 160 natural

secondary

forest

5 minute walk from CFNR

Forest Science Building

2 1 ha. Maitim Moderate to

steep

260-265 natural

secondary

forest

15 to 20 minute walk from

PFLA No.1

3 1 ha. Maitim rolling

topography

270 core area is

a 70-year old

mahogany

plantation

100 m away from PFLA No. 2

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PFLA 1

PFLA 2PFLA 3

MFR

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Litterfall collection and production

Litter was collected at interval of one month from August 2006 to July 2007 using 0.5 m2 traps

Sampled litters were sorted separately into leaf and non-leaf part and then placed in properly labeled paper bags and oven-dried for 48 hours at 700C

Total litter was obtained by adding their weights and expressed in g m2

Litter decomposition

The litter bag technique was used

to monitor the rate of leaf litter

decomposition, using a 20 x 20 cm

litter bag with mesh of 1.5 mm

Approximately 15 grams of leaf

litter were placed in every bag

The rate of decomposition was

expressed as percent loss in initial

weight over oven-dry weight

Monthly change in weight was

monitored and determined

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Monitoring of microclimate

Environmental factors like, light intensity, relative humidity, and air temperature were quarterly measured and recorded.

The amount of light intensity in lux was determined using a light meter.

The digital thermohygrometer was used to measure the relative humidity and air temperature.

These environmental factors will be correlated with the possible influence on seedling growth, survival of the regenerations, and volume of litterfall.

Results and Discussion

Basic structure and composition

4231

38

97

63

78

122

8796

0

20

40

60

80

100

120

140

PFLA 1 PFLA 2 PFLA 3

PFLA

Nu

mb

er Family

Genera

Species

PFLA site- dominated by Celtidaceae, Meliaceae and Tiliaceae

Tallest trees recorded is narra (49.8m) and biggest dbh in kanapai (171 cm)

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Population structure dynamics of main component trees in PFLA 1

SpeciesMean

DBH

Density

(ha-1)

BA

(m2 ha-1)

RD

(%)

Rdom

(%)

RF

(%)

IV

(%)

Celtis luzonica 9.7 108 0.79 11.0 3.2 11.0 25.2

Swietenia macrophylla 11.2 103 1.02 10.5 4.1 10.5 25.1

Parashorea malanonan 33.9 24 2.16 2.4 8.7 2.4 13.6

Triplaris cumingianus 5.5 71 0.17 7.2 .7 7.2 15.1

Pometia pinnata 20.3 33 1.07 3.4 4.3 3.4 11.0

Pterocarpus indicus 28.4 23 1.46 2.3 5.9 2.3 10.6

Strombosia philippense 11.0 37 0.35 3.8 1.4 3.8 9.0

Diplodiscus paniculatus 19.4 27 0.79 2.7 3.2 2.7 8.7

Pouteria duclitan 16.2 28 0.57 2.9 2.3 2.9 8.0

Knema glomerata 11.0 32 0.30 3.3 1.2 3.3 7.7

Stand density (ha-1) 984

Total basal area (m2 ha-1) 24.9

IV provide an overall estimate of the influence or importance of tree species in a community

Summary of survival rate by species of regenerants in PFLA 2

Species

# of

seedlings

8/1/2006

# of

seedlings

12/1/2006

Survival

rate (%)

Celtis luzonica 33 31 93.94

Strombosia philippinensis 27 24 88.89

Diplodiscus paniculatus 5 5 100.00

Swietenia macrophylla 2 2 100.00

Papulathia lanceolata 2 1 50.00

Aglaia iloilo 1 1 100.00

Nephelium mutabile 1 1 100.00

Palaquium philippense 1 1 100.00

Aglaia diffusa 1 1 100.00

Drypetes maquilingesis 1 1 100.00

Total 82 85 92.39

Mortality of old regenerations was compensated by the number of new

regenerations although not of the same species.

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Summary of survival rate by species of regenerants in PFLA 3

Species

# of

seedlings

8/1/2006

# of

seedlings

12/1/2006

Survival

rate (%)

Swietenia macrophylla 240 162 67.50

Strombosia philippinensis 33 30 90.91

Artocarpus ovata 5 5 100.00

Diospyros pilosanthera 3 3 100.00

Streblus asper 2 2 100.00

Garcinia biunucao 2 2 100.00

Parashorea malaanonan 2 2 100.00

Ficus nota 1 1 100.00

Aglaia diffusa 1 1 100.00

Neotrewia cumingii 1 1 100.00

Artocarpus blancoi 1 1 100.00

Spathodea campanulata 1 1 100.00

Total 293 212 72.35

Mahogany seedling were present in all PFLA sites because nearest potential mother trees

were located in all plots. Mahogany seeds are wind dispersed thus they can travel several

meters before reaching the ground for germination

0-50 50-100 1-300 above 300

0

50

100

150

200

250

300

Distribution of seedling height of PFLA sites in Mt. Makiling.

PFLA1

PFLA2

PFLA3

Height (cm)

Nu

mb

er

Most of seedling height were distributed from 0-50cm. Showed

typical reverse-J-shape

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1-10mm 10-20mm 20-30mm above 30mm

0

50

100

150

200

250

300

Distibution of seedling root collar diameter of PFLA sites in Mt. Makiling.

PFLA1

PFLA2

PFLA3

Diameter (mm)

Num

ber

Seedling root collar diameters concentrated on 1-10 mm. Pattern

showed typical reverse-J-shape.

Litterfall production in the PFLA sites

(Values in italics represent percentages of each litter components)

SiteLeaf

(g m2 yr-1)

Non-Leaf

(g m2 yr-1)

Total

(g m2 yr-1)

PFLA 1 992 (75.95) 314 (24.04) 1306

PFLA 2 1254 (80.49) 304 (19.51) 1558

PFLA 3 981 (75.57) 317 (24.42) 1298

Leaf litter constituted 76%-80%, while non-leaf ranged from 19-24% of the total

litterfall.

Non-leaf part was higher PFLA 3 maybe because of bigger biomass prod’n of

mahogany plantation.

In contrast of Cuevas and Sajise that mature trees produced 3 x more than the

young trees.

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August, 2006

September

October

November

December

January, 2007

February

March

April

May

June

July

0

50

100

150

200

250

300

PFLA 1

PFLA 2

PFLA 3

Month

Lit

terf

all (

g/m

2/y

r)

Seasonal variation in leaf litterfall in the PFLA sites in Mt. Makiling.Two peaks of litterfall, dry season (Jan-April) and start rainy season (September),

much higher in dry season.

Highest in Feb/March for PFLA 3 because trees shed their leaves and maybe due

to water stress and maturity of leaves.

August, 2006

September

October

November

December

January, 2007

February

March

April

May

June

July

0

10

20

30

40

50

60

70

80

90

100

PFLA 1

PFLA 2

PFLA 3

Month

Lit

terf

all

(g

/m2/y

r)

Seasonal variation in non-leaf litterfall in the PFLA sites in

Mt. Makiling.

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August, 2006

September

October

November

December

January, 2007

February

March

April

May

June

July

0

50

100

150

200

250

300

350

PFLA 1

PFLA 2

PFLA 3

Month

Lit

terf

all (

g/m

2/y

r)

Seasonal variation in total litterfall in the PFLA sites in

Mt. Makiling.

Litter decomposition (remaining weights in litter bag)

September, 2006

October

November

December

January, 2007

February

March

April

May

June

July

August

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

PFLA 1

PFLA 2

PFLA 3

Month

Weig

ht

loss (

g)

Litter loss weight continuously as it stays longer on the soil.

Analysis will be conducted whether the rate of litter decay varied in PFLA sites.

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Problem encountered and recommendations

1. Frequent loss of littertaps.

2. There are certain tree species whose seedlings are difficult to identify in the field.

3. Regeneration surveys should be conducted annually for several years following any type of treatment to closely monitor changes in population structure.

4. If seedling densities continue to drop or productivity declines or trees start to dies, some form of remedial treatment should be initiated:

* enrichment planting for enhancing the seedling abundance of a valuable species

* selective weeding to increased survival and growth of young plants and decreases the competition at ground level

*cutting and removing woody vines from the crowns of adult trees

Acknowledgments

UP Los Baños - College of Forestry and Natural Resources

Commission on Higher Education (CHED)

Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD)

UPLB Basic Research Program

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