Leave No TraceLeave No TraceOutdoor Skills and EthicsOutdoor Skills and Ethics

The Science behind the PracticesThe Science behind the Practices

TT22 TT33 TT55II22 II33 II44II11

TT44

II55

TT11 TT66

Soil LossSoil Loss

Presentation ObjectivesPresentation Objectives

Describe recreation ecology research and how it helps inform the development of Leave No Trace practices.

Highlight some of the more relevant research findings for each Leave No Trace principle.

LNT practices are science-based:

The LNT MessageThe LNT Message

Recreation ecology research tells us about recreation impacts and the relative influence of use-related, environmental, and managerial factors. This information helps us to develop effective Leave No Trace practices.

The LNT MessageThe LNT MessageSocial science research tells us about visitor attitudes, behaviors, social norms, and effective methods of communicating low impact practices.

Haleakala National ParkHaleakala National Park(Simulation - proliferation of informal trails)(Simulation - proliferation of informal trails)

Impact Indicators

Park ZonesDevelope

d(11.7 ha)

Threshold(16.2 ha)

Natural(235.1

ha)Aggregate Length (m) Formal Trails 1509 1844 10,288 Informal Trails 443 5532 5813Disturbance Area (m2) Formal Trails 3880 3349 24,970 Informal Trails 261 4335 5647Lineal Extent (m/ha) Formal Trail Length 129 114 44 Informal Trail Length 38 341 25Density (m2/ha) Formal Trails 2571 1816 2427 Informal Trails 589 784 971

Informal (Visitor-Informal (Visitor-Created) Trail ImpactsCreated) Trail Impacts

The Seven LNT PrinciplesThe Seven LNT Principles

1. Plan Ahead and Prepare2. Travel and Camp on Durable Surfaces3. Dispose of Waste Properly4. Leave What You Find5. Minimize Campfire Impacts6. Respect Wildlife7. Be Considerate of Other Visitors

1. Plan Ahead and Prepare1. Plan Ahead and Prepare

Schedule your trip to avoid times/areas of high use.

New campsites are often created on high use weekends. Even a few nights camping each year prevents their recovery.

The potential for social impacts (e.g., crowding and conflict) is far greater during high use periods.

1. Plan Ahead and Prepare1. Plan Ahead and Prepare

Schedule your trip to avoid times when resources are vulnerable.

Vegetation and soils are far more susceptible to impact when wet.

Wildlife are more sensitive to disturbance during mating, nesting/birthing, and winter seasons.

2. Travel and Camp on Durable 2. Travel and Camp on Durable SurfacesSurfaces

Experimental trampling studies reveal that trampling impacts can be avoided/minimized when you:

Best: Stick to rock and naturally barren substrates,

Best: Walk on the center of well-established trails or camp in the core barren portions of campsites,

Good: Confine traffic to non-vegetated organic litter,

OK: Confine traffic to dry grasses; avoid herbs.

1000 passes

Resistance and Resilience: Resistance and Resilience: ForbsForbs

0 passes

250 passes

1 mo. later

Forest forbs generallyhave low resistance and resilience.

1000 passesResistance and Resilience: GrassesResistance and Resilience: Grasses

0 passes

250 passes

1 mo. later

Grasses generallyhave high resistance and resilience.

Vegetation ImpactsVegetation ImpactsVegetation trampling

Reduction in height

Compositional change:Fragile to resistant

Native to non-native

Loss of vegetation cover

Soil ImpactsSoil ImpactsTrampling and

pulverization of organic litter

Loss of organic litter

Compaction of soil:Increased runoffDecreased soil

moisture

Use-Impact Relationships: Use-Impact Relationships: A Campsite ExampleA Campsite Example

0 10 20 30 40 50 60 70Nights/Year

0

20

40

60

80

100

Impa

ct (%

)

Vegetation Loss Soil Exposure Litter LossSeedling Loss Soil Density

The majority of most types of impact occur at low use levels

Rationale for Dispersal & Containment Rationale for Dispersal & Containment StrategiesStrategies

The Use/Impact Relationship

Amount of Use

Impa

ct

What are the implications of the curvilinear use/impact relationship for selecting a low-impact campsite?

Nights/Year

Impa

ct

15

a

.

.Consider an area where camping is unregulated with 3 sites that receive 15 nights/yr

Rationale for Dispersal & Containment Rationale for Dispersal & Containment StrategiesStrategies

The Use/Impact Relationship

Impa

ct

All permanent impact could be avoided if use from the 3 campsites could be dispersed to 45 sites, each with 1 night of camping/year.

Management experience has shown this level of dispersal to be exceedingly difficult to achieve.

Dis

pers

al

.1 Nights/Year

Rationale for Dispersal & Containment Rationale for Dispersal & Containment StrategiesStrategies

The Use/Impact Relationship

Impa

c t

ContainmentContainmentb

45

Close 2

campsites

.

.

15

a

.

.A containment policy is more effective. Use from 2 closed campsites is shifted to the 3rd. Cumulative impact is reduced from a (3 x a) amount of impact to a (1 x b) amount of impact.Nights/Year

Rationale for Dispersal & Containment Rationale for Dispersal & Containment StrategiesStrategies

The Use/Impact Relationship

Temporal Trends: Temporal Trends: Life-History of a Campsite or TrailLife-History of a Campsite or Trail

Impacts occur quickly; recovery can require up to 30 yrs.

Implications: Use only well-established sites & trails; avoid lightly impacted sites/trails to promote their recovery.

Establish

ment

Closure

Full Recovery

Impa

ct

Time1 yr 10-30 yrs

TravelingTraveling

Stay on designated or well-established trails whenever possible.

In popular areas:

Disperse traffic on the most resistant pristine surfaces if you must leave trails.

In pristine areas:

CampingCamping

Stay on designated or well-established campsites. Restrict activities to the most highly disturbed areas.

In popular areas:

Choose a pristine site with resistant surfaces. Disperse activities to avoid impact.

In pristine areas:

3. Dispose of Waste Properly3. Dispose of Waste Properly

Studies have shown bacteria to be present one year after cat-hole waste burial. Decomposition is aided by stirring the waste together with soil and water.

Pathogens can effectively filtered from water moving through < 5 feet of medium-textured soils so cat-holes do effectively protect water resources.

Desiccation, high temperatures, and UV radiation are lethal to pathogens but are highly effective only for thinly smeared surface-deposited waste.

3. Dispose of Waste Properly3. Dispose of Waste Properly

Recommendations: Use toilets, carry-out, or cat-hole wastes.

Surface deposition is problematic due to aesthetics, animal and insect transmission of diseases, and the greater potential for water contamination.

Burial (6-8”) in fine-textured soil >200 ft from water.

Group latrines not recommended – the large mass of wastes would slow decomposition time.

Snow – carry-out is the best option.

4. Leave What You Find4. Leave What You Find

Avoid introducing or transporting non-native species.

Studies have surveyed hikers at trailheads and found numerous seeds on the clothing of hikers and in their gear. Clean your clothing, boots, and gear of seeds before you depart home.

Many non-native plants remain in the vicinity of trails and campsites. However, a few highly invasive plants are able to out-compete native vegetation in undisturbed environments (e.g., Japanese stilt grass)

Researchers have also germinated non-native seeds that have passed through the intestines of horses.

4. Leave What You Find4. Leave What You FindLeave flowers for others to see. Picking them prevents formation of seeds vital to their reproduction and survival. A Great Smoky Mtn. NP study found significantly fewer orchids along trails in comparison to more distant areas.

5. Minimize Campfire Impacts5. Minimize Campfire Impacts

Campfires can cause lasting impacts to the backcountry. Research shows that campfire-related impacts are both socially and ecologically significant.

Campfire sites remind others that the area is not pristine, large mounds of charcoal with trash are an eyesore, firewood depletion can leave a human “browse line” and tree damage and stumps represent acts of depreciative behavior.

Tree cutting removes dead trees important for cavity-nesting wildlife. Firewood depletion diminishes nutrient cycling and soil macro-fauna. Campfires produce long-term changes in soil physical and chemical properties.

5. Minimize Campfire Impacts5. Minimize Campfire Impacts

Avoid campfire-related impacts by using a stove.

A study of backcountry A study of backcountry camping impacts at Great camping impacts at Great Smoky Mountains National Smoky Mountains National Park found 2,377 damaged Park found 2,377 damaged trees and 3,366 stumps!trees and 3,366 stumps!

Leave woods tools at homeLeave woods tools at home

6. Respect Wildlife6. Respect Wildlife

Research shows that small mammal populations supported by human food reach unsustainable levels that promote disease transmission or starvation during the off-season.

Another study found that the cessation of long-term artificial feeding left some animals with an inability to locate natural food. The young of such animals may never learn to forage for natural foods – tantamount to a death sentence.

6. Respect Wildlife6. Respect WildlifeKeep wildlife wild.Never feed wildlife or allow them to obtain human food or trash.

Wildlife attracted to human food often suffer nutritionally, alter their natural behavior and expose themselves to predators and other dangers.

Managers at Grand Canyon had to kill 22 fed deer, some with up to 5 lbs of plastic clogging their intestines. A fed deer in Yosemite killed a small child.

6. Respect Wildlife6. Respect Wildlife

New habitats are unfamiliar, often have lower quality food and cover, or increased competition and predation.

Displacement – animals are forced away from preferred habitats e.g., food/water sources or cover, either during certain times (temporal displacement) or in certain places (spatial displacement).

Studies reveal that > 2/3rds of wilderness visitors report that seeing large groups reduces their feeling of solitude and being in wilderness.

However, group size is generally among the lowest ranked problems in comparison studies and < 50% report that seeing large groups is a problem.

Research indicates that a group’s actual behavior is more important than its physical size. Large groups can camp quietly away from others and adopt low impact camping practices.

7. Be Considerate of Other Visitors7. Be Considerate of Other VisitorsSocial Research on Group Size

Only one empirical study and several suggestive studies…Large groups burned more firewood, but less wood per person, than smaller groups.Wildlife would likely be less disturbed by a smaller number of larger groups than by a larger number of smaller groups.Large groups can reduce their impact by staying on well-established trails and campsites – a dispersal strategy is more difficult for large groups.

Ecological Research on Group Size Ecological Research on Group Size

Large groups substantially expand campsites when they camp even one night on a site that’s too small. Any subsequent use of newly expanded areas prevents recovery.

Large groups can reduce their impact by: breaking into smaller groups to hike and camp,

confining their activities to already impacted areas away from other groups,

meeting infrequently as a large group and only on durable surfaces, and

practicing quiet and courteous behavior.

Ecological Research on Group SizeEcological Research on Group Size

The EndThe End

Happy trails and remember Happy trails and remember to . . .to . . . Leave No Trace !Leave No Trace !

Sunset, Haleakala Volcano, Haleakala National Park, HawaiiSunset, Haleakala Volcano, Haleakala National Park, Hawaii