Habitat alteration (i.e. degradation, fragmentation, and destruction) is the primary driver of amphibian decline and extinction. Despite their ecological importance and threatened status, very little long-term research has been conducted on how methods of forest management impact salamanders. In this research, I examine how experimental silviculture impacts plethodontid salamander relative abundance and count, and I compare three different body condition indices. Chapter 1 focuses on plethodontid salamander relative abundance 30 years after experimental treatments (including clearcut and shelterwood harvests, understory herbicide, uneven-aged management, and an untreated control) were first applied. I found that plethodontid salamander populations in all silvicultural treatments without stand re-entry have reached pre-harvest relative abundance levels. Chapter 2 describes how artificial tip-up mounds that could be used to mimic old-growth forest characteristics impact plethodontid salamander count. Salamander count significantly declined in treatment units with artificial tip-up mounds but this could be an artifact of the heavy disturbance required for installation. Chapter 3 compares three different body condition indices for plethodontid salamanders. I found that bioelectrical impedance analysis (BIA) is likely not suitable for use with plethodontid salamanders and mass divided by snout-to-vent-length is likely a superior estimate to tail width divided by snout-to-vent-length. These findings further our understanding of how different forest management practices affect salamander populations and provide guidance for evaluating body condition. / Master of Science / Forest understory salamanders play an important role in energy transfer and their position in leaf litter food webs affects multiple ecosystem functions. Despite their ecological importance, very little long-term research has been conducted on how habitat change impacts salamanders. This research investigates how different forest management techniques influence forest-dwelling salamanders and compares three different ways to evaluate salamander health. Chapter 1 focuses on the salamanders 30 years post-harvest. I found that salamander populations in all silvicultural treatments except one had recovered. Chapter 2 described how tipping over trees to mimic old-growth forest characteristics impacts the number of forest-dwelling salamanders. There were significantly fewer salamanders in treatment units after the disturbance created by installing artificial tip-up mounds. Chapter 3 compares three different ways to evaluate forest-dwelling salamander health. I found that bioelectrical impedance analysis (BIA)is likely not suitable for forest-dwelling salamanders, and weight divided by body length is likely a superior estimate to tail width divided by body length. These findings together further our understanding of how different forest management practices affect salamander populations and provide guidance for evaluating body condition.

Disturbance events affect forest composition and structure across a range of spatial and temporal scales, and forest development may differ after natural, anthropogenic, or compound disturbances. Following large, natural disturbances, salvage logging is a common yet controversial management practice around the globe. While the short-term impacts of salvage logging have been studied in many systems, the long-term effects remain unclear. Further, while natural disturbances create many persistent and unique microsite conditions, little is known about the long-term influence of microsites on forest development. We capitalized on over eighty years of data on stand development following the 1938 hurricane in New England to provide the longest known evaluation of salvage logging impacts, as well as to highlight developmental trajectories for eastern hemlock (Tsuga canadensis)-white pine (Pinus strobus) forests under a variety of disturbance histories. Eight decades following disturbance, there were no differences in current overstory composition between areas that were logged, hurricane disturbed, or hurricane disturbed and salvage logged, but white pine declined across most sites. In contrast, structural characteristics remain distinct between the three management histories. In the unsalvaged area, the diversity of microsites and the coverage of uprootings and pits influenced overstory tree composition, diversity, and structural characteristics. These findings underscore the long-term influence of salvage logging on forest development and the importance of natural disturbance-mediated microsite conditions on tree species growth and survival. Future salvage logging efforts should consider these impacts and provide a greater range of unsalvaged areas across the landscape to maintain these important structural legacies over the long term.

Riparian wetlands may provide numerous ecosystem services, including water quality protection, food and fiber supply, wildlife habitat, and carbon sequestration. In recent years, riparian forests have received increased attention and funding for riparian forest restoration projects. Unfortunately, failures of riparian restoration efforts are likely due to mortality of planted trees. Tree mortality is commonly attributable to several factors, including selection of species that are not well suited to the wetland sites, inadequate planting densities, soil compaction associated with former agricultural activities, lack of microtopographic relief that allow small seedling to survive on wet sites, competition by herbaceous plants, and browse. Selection of well-suited species, dense planting and use of mechanical soil site preparations are all potential remedies to partially address success of wetland restoration plantings. Riparian restoration projects have historically been undertaken with goals of improving water quality and/or wildlife habitat, but in recent years there has been increased valuation of carbon sequestration. Carbon valuation appears to be increasing, but more research is needed to determine rates and pools of carbon accumulation in riparian areas. Our research quantifies forest establishment effects on multiple carbon pools in a densely planted, 12-year-old old-field riparian restoration. Our research evaluated the effects of four soil mechanical site preparations (bed, disk, pit, and mound and rip) and species selection (American sycamore (Platanus occidentalis) and willow oak, (Quercus phellos) on forest establishment and carbon storage across multiple pools, namely in planted trees, herbaceous vegetation, fine roots, organic soil horizons, and the mineral soil. At 12 years, we found that species selection was more important to carbon storage than site preparation. American sycamore was well suited to the site and had better survival than willow oak (64% vs 42% survival). American sycamore also stored more carbon across all site preparations than willow oak. Measured carbon storage averaged 74.8 Mg ha-1 for American sycamore treatments and 63.1 Mg ha-1 for willow oak treatments. The plots were densely planted (1.2 m (4ft) by 1.8 m (6ft) spacing), and forests were established even in higher mortality willow oak plots. These results indicate that high planting density is potentially a viable practice for establishing riparian forest cover, especially if desired species are marginally site suited or other survival inhibiting factors exist. / Master of Science / Riparian forests located within the floodplain of streams are known to protect stream water quality, provide wildlife habitat, and store carbon. Due to these benefits, trees may be replanted on riparian areas that were formerly used for agriculture. Unfortunately, trees planted on these restoration sites have often died. The tree mortality may be due to planting incorrect tree species that may struggle on wet floodplains, soil compaction from agricultural practices, not enough trees being planted, and restored floodplains lacking small, elevated areas common across natural wetlands known to favor tree rooting and survival. Reasonably, selecting species that are well suited to a specific site, planting trees more densely, and using plowing methods designed to break up compaction and create some relief in elevation would amend these issues. Traditionally, floodplain restorations have focused on improving water quality and providing habitat for wildlife, but the benefits of storing carbon have become increasingly valuable in recent years. While we know that wetlands store carbon, research is needed to examine how quickly and where carbon is stored. Our research quantifies forest establishment and carbon storage of very densely planted, 12-year-old American sycamore (Platanus occidentalis) and willow oak (Quercus phellos) plantations. This research examines the effects four soil tillage methods and tree species selection had on tree survival and carbon storage. Carbon storage was measured in vegetation, soil, and small roots. Twelve years after planting, species selection had a greater impact on carbon storage than soil tillage methods. No tillage method altered survival or total carbon after 12 years, but American sycamore was found to have better survival and more carbon than willow oak in all soil tillage treatments. Both species were successful in establishing planted forests on the floodplain, but the success was aided by the very high initial numbers of planted trees that ensured enough trees would survive on the site even after trees were lost to mortality. Creation of willow oak forests benefitted more from dense planting, as it was less suited to the site and more planted willow oaks died. We recommend tillage for compacted soil, selecting the most suitable tree species, and planting adequate numbers of trees.