Impact Of Logging On Wildlife/ Agriculture

Front 1

what does logging do

Back 1

 Reduces abundance of large mature trees, doesn’t necessarily fragment forest beyond road networks, skid-trails and log bays, especially if heavy machinery avoided.

Front 2

Dipterocarps

Back 2

Dipterocarps more vulnerable to logging. Successful recruitment dependent on massive synchronous fruiting. Reduction in no of fruiting trees may mean production no longer enough to satiate predators.

Front 3

butterflies, birds. insects etc

Back 3

 Butterflies higher spp richness and abundance unlogged forest, some abundant in both types.
Birds no consistent trend. Community composition changes greatly, various forest specialists, espesh understorey insectivores, declining/ temporarily disappearing from logged sites.

Front 4

Mammals

Back 4

 Less known about mammal responses to logging. Responses taxon-specific. Changes abundance and type of available food- fruit readily available unlogged forest- affects primate distribution, ungulates, and some civets. Asian fruit bats do well in human dominated landscapes-high mobility. Insectivorous bats don’t do so well, invertebrates less abundant, efficiency of echolocation declines in more open areas. Tolerance to logging may be related to phylogenetic age- older spp more vulnerable. Most are endemic to insular SE Asia and have specialised diets. Those evolved more recently, tolerant to logging- generalists, use all vegetation strata, and widespread

Front 5

frogs and toads

Back 5

sensitive to dessication. Logging causes loss of water bodies, increases stream temp and sedimentation, aquatic tadpoles sensitive to. Anurans that have entire life cycle in leaf litter sensitive to desiccating effects of canopy opening- however, support in studies for this is varied- attributed higher no in 8-10 yr old logged forest to higher no of microhabitats.

Front 6

fish

Back 6

logging can reduce stream inputs by changing structure of surrounding habitat, reduce amount of overhanging vegetation. Reduce shading increases stream temp, lowers dissolved oxygen levels, increasing fish metabolic rates. Fish mortality can increase oxygen depletion. Increased turbidity-clogs gills, smothers food resources and spawning grounds. Fish resistant to selective logging, caused initial decline, but had little LT impact overall in Sabah.

Front 7

logged forests

Back 7

May recover spp

Front 8

fragmentation

Back 8

isolated forest fragments <100ha lose half their forest dependent birds within 15 years. Birds deemed forest specialists most sensitive. Sedimentary birds least vulnerable. For other birds, sensitivity= function of properties of habitat surrounding forest fragments over which they might disperse.

Front 9

fragmentation

Back 9

• Insectivorous birds more vulnerable as they are sedentary understory specialists, specialised foraging strategies. Mixed spp flocks segregate following isolation, can recover if they can move across matrix, but they have poor dispersal ability and ltd adaptability to modified habitat.
• Beetles depleted in <100ha. Bee taxa differ in response. Honey bees less forested landscapes.

Front 10

Dunn 2004-

Back 10

- forest conversion to agric or pasture decreased spp richness of ants and of animals overall, logging didn’t decrease spp richness of ants, birds or lepidoptera. After sites were abandoned, diversity of logged sites didn’t change over time. Diversity of old fields increased w time. Ants, birds and lepidoptera responded similarly to forest clearance or disturbance, for logging or conversion. Selective logging less of an impact on diversity than does conversion.

Front 11

Barlow et al 2005

Back 11

low-intensity logging still had markedly different composition of understorey birds from undisturbed forests.