Husband and wife team Luis Malaret and Dianne Rocheleau bring students into the field to study the effects of forest management practice on the habitats of reptiles, amphibians and ants.
Effects of silvicultural practices
Principal Investigators: Luis Malaret (Marsh Institute at Clark University), Dianne Rocheleau (Marsh Institute at Clark University), Marla Emery (USDA Forest Service), Gary Wade (USDA Forest Service)
- Purpose of Proposed Study
- Study Organisms
- Field Methods
- Survey Techniques
- Amphibians and Reptiles Found at the Study Site
- Ant Genera Identified to Date
Purpose of Proposed Study
This study proposes to examine the long-term effects of distinct silvicultural treatments on the composition of less studied faunal components of the forest community in the Adirondack Mountains. The changes in these faunal groups will also serve as indicators of broader differential effects of treatments on forest ecology.
The taxa chosen for study, reptiles and amphibians (herpetiles), and ants, were selected because they:
- are representative of different trophic levels (secondary consumers and detritivores), taxonomic groups (vertebrates and arthropods), and habitat niches (Majer 1983);
- include taxa with a high degree of species richness including common and rare species (Powell & Henderson 1996);
- are well studied (Holldobler & Wilson 1990);
- respond rapidly to changes in land use and land cover (Altagracias 1985, Roth et. al. 1994);
- can be sampled relatively easily; and
- are less often studied than birds and mammals in biodiversity research.
Invertebrates represent most of the animal species found in terrestrial ecosystems. Any study examining the interaction between land use change and the biotic community must include invertebrates. Ants are among the most common, abundant and diverse invertebrates in terrestrial ecosystems (MacKay & Vinson 1989), often representing a high proportion of the insect species present. Ant community structure has been found to respond rapidly to environmental changes (Majer 1983, Roth et. al., 1994). Species abundance differed between forest and fallow agricultural land in Nigeria (Ewuim et. al. 1997) and species composition changed in forest, grassland and agricultural ecosystems in Puerto Rico (Torres 1984b). Ants have also been found to be good indictors of biodiversity (Roth et. al. 1994), pertubation (Burbridge et. al. 1992, Majer 1992, Olson 1991, Brown 1989), and rehabilitation or successional stages (Majer 1983 and 1985). Ants have been studied extensively (Holldobler and Wilson 1990), are well known taxonomically (MacKay and Vinson 1989), and relatively easy to collect and identify (Clark & Blom 1992, Jaffe et. al. 1993, Olson 1991). A variety of sampling methods are quite effective in collecting ants including pitfall traps, baited traps and manual collection (Olson 1991).
Reptiles and amphibians are often local top carnivores feeding heavily on invertebrates (Wake 1991). Amphibians are especially good biological indicators of environmental stresses because of their dependence on both aquatic and terrestrial habitats and because of their highly permeable skin (Blaustein & Wake 1990, Jacobs 1998). Many amphibian species have undergone recent population decline, range reduction and, in some cases, extinction (Wake 1991, Pelley 1998).
The three taxa under study should serve as excellent indicator species for faunal responses to the silvicultural treatments under study.
Systematic surveys of the ant and herpetological (amphibian and reptile) communities were initiated in the summer of 1999 on 6 of 14 treatment blocks in a long-term silvicultural experiment being conducted by the Aiken Forestry Lab, Paul Smith College and the Adirondacks Park Agency Visitor Information Center. Subsequent to the initial survey, pairs of blocks underwent one of the following silivicultural treatments: clearcut, no cut and single species cut. A follow-up survey will be run this summer (2000) and funds are requested to continue surveys in the next three years (2001 - 2003). Future funding efforts will be sought to conduct surveys in 2009, 2014 and 2019 (10, 15 and 20 years post-treatments).
The 4 central plots (22.56m diameter circles) in each block are surveyed. Since the study organisms are most often found on or in the leaf litter and under debris (e.g. fallen logs, rocks), each survey consists of three components. First a walk through a plot is conducted to search for all study organisms on the surface. Next all above-ground objects including debris, bases of tree trunks, tree roots and associated leaf litter (within .3m of the object), are checked, as is a comparable area of leaf litter not associated with objects. The leaf litter (down to the soil) is carefully sifted through (by hand) in search of herps, ants and ant nests. Three forths of the total surface is searched. Finally 20 baited ants traps are set in pairs at 2m intervals along 2 diameter-length lines perpendicular to each other. Traps are set in the morning and checked in the evening and again the subsequent morning.
The project includes an educational component as both graduate and undergraduate students will work closely with the senior researcher, learning how to design and conduct field research.
Amphibians and Reptiles found at the Study Site
Ambystoma maculatum (Spotted Salamander)
Desmognathus fuscus (Dusky Salamander)
Desmognathus ochrophaeus (Mountain Dusky Salamander)
Eurycea bislineata (Two-lined Salamander)
Plethodon cinereus (Redback Salamander)
Bufo americanus (American Toad)
Rana sylvatica (Wood Frog)
Rana clamitans melanota (Green Frog)
Rana palustris (Pickerel Frog)
Pseudacris crucifer (Spring Peeper)
Thamnophis sirtalis (Garter Snake)
Ant Genera Identified to Date
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Olson, D. 1991. A Comparison of the efficacy of litter sifting and pitfall traps for sampling leaf litter ants (Hymenoptera: Formicidae) in a tropical wet forest, Costa Rica. Biotropica 23(2):166-172.
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Torres, J. A. 1984a. Niches and coexistance of ant communities in Puerto Rico. Biotropica 16(4):284-295.
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