Initial Effects of Clearcutting and Alternative Silvicultural Practices on Terrestrial Salamander Abundance

Abstract

Several studies have demonstrated the negative effects of clearcutting on terrestrial plethodontid salamander populations. However, none has experimentally compared clearcutting with multiple alternative timber-harvest methods. Using a randomized, replicated design, we compared the short-term effects (1-4 years after harvest) of clearcutting to effects of leavetree, group selection, and two shelterwood cuts on terrestrial salamanders in the southern Appalachian Mountains of Virginia and West Virginia (U.S.A.). Treatment plots were 2 ha each. We also compared salamander age class (percent juvenile), fecundity (percentage of females carrying eggs and average number of eggs per gravid female), size of gravid females, and species composition and diversity between treatments with canopy removal ( cut ) and those without canopy removal ( uncut). All treatments with canopy removal had significantly fewer salamanders than the control treatment, but salamander abundances on alternative treatments with canopy removal did not differ significantly from salamander abundances on the clearcuts. There were no significant differences between cut and uncut treatments in the proportion of females that were gravid or in the average number of eggs in gravid females; however, gravid Plethodon cinereus females weighed more on the cut treatments and gravid Desmognathus ochrophaeus females weighed more on uncut treatments. There were no significant differences between cut and uncut treatments in the proportion of the sample that was juvenile, except in the largest species tested, P. glutinosus , which had a significantly higher proportion of juveniles in the uncut treatments. We conclude that initial declines in terrestrial plethodontid abundance caused by timber harvesting may be minimized across the landscape by concentrating high-intensity timber harvesting ( clearcutting ) in small areas ( a few hectares in size ). Efectos Iniciales de la Tala Rasa y de Prácticas Silvícolas Alternativas sobre la Abundancia de Salamandras TerrestresResumen: Varios estudios han demostrado los impactos negativos de la tala rasa sobre poblaciones de salamandras pletodóntidas terrestres. Sin embargo, ninguno ha comparado experimentalmente la tala rasa con múltiples métodos alternativos de cosecha de madera. Utilizando un diseño aleatorio, replicado, comparamos los efectos a corto plazo (1-4 años postcosecha) de la tala rasa con los efectos de prácticas silvícolas alternativas sobre salamandras terrestres en el sur de las montañas Apalaches en Virginia y Virginia del Oeste (E.U.A.). Las parcelas de tratamiento eran de 2 ha cada una. También comparamos la clase de edad de salamandras (porcentaje de juveniles), fecundidad (porcentaje de hembras con huevos y promedio de huevos por hembra grávida), tamaño de hembras grávidas y composición de especies y diversidad entre tratamientos con remoción de dosel (corte) y sin remoción de dosel (sin corte). Todos los tratamientos con remoción de dosel tuvieron un número significativamente menor de salamandras que el con...

Effects of timber harvesting on terrestrial survival of pond-breeding amphibians

“…There are fewer studies of the potential mechanisms that give rise to these changes, and several non-competing mechanisms may explain reductions in post-harvesting amphibian abundance and diversity, such as emigration from cleared forests, loss of breeding wetlands and failed recruitment, behavioral changes, or demographic changes. Whereas Knapp et al (2003) found no significant effects of harvesting on the demography of terrestrial plethodontid salamanders, Homyack and Haas (2009) found that juveniles were more abundant in unharvested treatments. The results of Homyack and Haas (2009) suggest that lower adult survival and fecundity, or lower juvenile recruitment, may explain the lack of juveniles in harvested areas.…”

Environmental and Anthropogenic Factors Influencing Salamanders in Riparian Forests: A Review

“…Most studies that examine the effects of clear-cuts on amphibians document higher abundance on control forest plots than on harvest plots, a trend that holds true for riparian forests [98,120]. deMaynadier and Hunter [118] found more than a threefold difference in amphibian abundance between control sites and clear-cuts.…”

“…Perkins and Hunter [125] conjecture that partial harvest is an effective way to maintain salamander communities along headwater streams, and Patrick et al [126] found that spotted salamanders and eastern red-backed salamanders prefer uncut and partial-cut habitat, as well as retained CWD. Knapp et al [120] believe that concentrating high-intensity timber harvesting (e.g., clearcuts) in areas only a few hectares in size would minimize declines in plethodontid abundance due to timber harvest. Crawford and Semlitsch [111] suggested uneven-aged timber harvest to protect stream amphibians.…”

Principal short-term findings of the National Fire and Fire Surrogate study

“…Petranka et al 1993Petranka et al , 1994Pough et al 1987), and retention of full canopy cover may positively affect salamanders (Harpole and Hass 1999, Homyack and Hass 2009, Knapp et al 2003. Little or no change in salamander abundance occurred after burns (Floyd 2003, Ford et al 1999, Knapp et al 2003).…”

“…Petranka et al 1993Petranka et al , 1994Pough et al 1987), and retention of full canopy cover may positively affect salamanders (Harpole and Hass 1999, Homyack and Hass 2009, Knapp et al 2003. Little or no change in salamander abundance occurred after burns (Floyd 2003, Ford et al 1999, Knapp et al 2003). A single burn increased abundance of reptiles and had no effect on numbers of amphibians in the short term (Ford et al 1999, Greenberg and Burning in many southeastern forests increased light penetration to the forest fl oor and stimulated herbaceous cover (Conner et al 2002, Wilson et al 1995, Wood et al 2004.…”