The effect of large woody debris, direct seeding, and distance from the forest edge on species composition on novel terraces following dam removal on the Elwha River, WA.

The removal of two dams on the Elwha River, Washington, exposed over 300 hectares of reservoir sediments and created primary successional habitats that posed challenges to revegetation efforts. In order to meet Elwha restoration goals, coarse sediment deposits would require revegetation methods aimed at quickly restoring native vegetation while deterring exotic species invasions. I examined the effect of two restoration treatments—large woody debris translocations and native seed enhancements—on plant species composition on novel terraces in the former Lake Mills reservoir four years after dam removal. I sampled vegetation in seeded and unseeded treatment areas with and without large woody debris. I also examined species composition and seed dispersal mechanisms to determine whether distance limited native plant recruitment from the nearby forest edge. I used two-way analysis of variance, NMDS ordinations, and permutational multivariate analysis of variance to determine whether wood placements, seeding treatments, and distance from the forest influenced species composition on novel terraces. My results revealed that Shannon-Weiner diversity, species richness, and percent exotics increased on plots containing wood, compared with surrounding bare sediments, but plant establishment did not substantially increase on wood plots. Plots located in seeded treatment areas had higher species richness and plant abundance, with decreased exotic species recruitment. As distance from the forest edge increased, Shannon-Weiner diversity, species richness, and percent exotics on unseeded plots declined, but plant abundance did not change significantly with distance. In addition, a greater proportion of plants were wind-dispersed at greater distances, while plants dispersed by gravity and ballistic mechanisms were associated with closer distances to the forest edge. This study’s results help fill a knowledge gap regarding the efficacy of using translocated large woody debris and direct seeding to restore vegetation in primary successional habitats following dam removal and helps inform best practices regarding the use of these restoration methods at future dam removal projects

The Role of Avian Seed Dispersers and Large Woody Debris in Plant Establishment Following Dam Removal on the Elwha River, WA

Reservoir drawdown following the removal of two hydroelectric dams on the Elwha River, Washington, exposed ~800 acres of sediments and left a barren landscape in the former reservoirs. The establishment of native vegetation within these areas is critical to meeting restoration objectives. Large woody debris (LWD) can play an important role in riparian ecosystems and may assist in the development of early plant communities. LWD helps create favorable microsites for seedlings by creating shade, which decreases temperatures and increases moisture levels in sediments. In sparsely-vegetated landscapes such as those present in the former Mills reservoir, wildlife such as birds can be effective seed dispersers. Logs provide perch structures upon which birds defecate and deposit seed-rich scat from vegetated areas into seed-limited habitats. The goal of my research is to examine the synergistic relationships between avian seed dispersal and LWD and to understand how LWD and birds interact to assist in plant establishment in the former Lake Mills reservoir. My research questions include: (1) is plant establishment greater at sites with LWD? Because LWD provides improved growing conditions due to the effects of shading and shelter from wind, which causes a decrease in sediment temperatures and evaporation rates, I hypothesize that there will be an increase in plant establishment as you approach LWD. (2) How are birds contributing to plant establishment in Mills? More specifically, what is the abundance and distribution of bird-dispersed seeds (scats), and what are the patterns in plant establishment from bird-dispersed seeds? Birds in the former Mills reservoir disperse seeds on woody perches. I hypothesize that scat abundance will be greater closer to seed sources on the vegetated valley walls and nearby forest. I also hypothesize that plant establishment from bird-dispersed seeds will be greatest around LWD. In order to address my first question I measured plant species composition and abundance on plots with and without LWD. I examined 7 variables and will use generalized linear mixed models (GLMM) and AIC scores to determine which variable combinations best predict plant abundance. I expect that plant establishment will be affected by the location, size, orientation, and layout complexity of LWD. To address my second question I will analyze LWD characteristics (height, volume, and location) and assess their effect on the abundance and distribution of avian seeds (scat) (collected in 2015). I will use generalized linear models (GLM) to analyze my data and will use ArcGIS to create density maps of avian seed dispersal and plant establishment, as determined by LWD, across the Mills reservoir. I anticipate that the results from my study will provide important information regarding patterns in avian seed dispersal and plant establishment around LWD will help inform adaptive management decisions regarding how birds may be utilized as vectors of seed dispersal and how resources of LWD can be best implemented to increase plant establishment in former reservoirs following dam removal

Disturbance type and species life history predict mammal responses to humans

Human activity and land use change impact every landscape on Earth, driving declines in many animal species while benefiting others. Species ecological and life history traits may predict success in human- dominated landscapes such that only species with - winning- combinations of traits will persist in disturbed environments. However, this link between species traits and successful coexistence with humans remains obscured by the complexity of anthropogenic disturbances and variability among study systems. We compiled detection data for 24 mammal species from 61 populations across North America to quantify the effects of (1) the direct presence of people and (2) the human footprint (landscape modification) on mammal occurrence and activity levels. Thirty- three percent of mammal species exhibited a net negative response (i.e., reduced occurrence or activity) to increasing human presence and/or footprint across populations, whereas 58% of species were positively associated with increasing disturbance. However, apparent benefits of human presence and footprint tended to decrease or disappear at higher disturbance levels, indicative of thresholds in mammal species- capacity to tolerate disturbance or exploit human- dominated landscapes. Species ecological and life history traits were strong predictors of their responses to human footprint, with increasing footprint favoring smaller, less carnivorous, faster- reproducing species. The positive and negative effects of human presence were distributed more randomly with respect to species trait values, with apparent winners and losers across a range of body sizes and dietary guilds. Differential responses by some species to human presence and human footprint highlight the importance of considering these two forms of human disturbance separately when estimating anthropogenic impacts on wildlife. Our approach provides insights into the complex mechanisms through which human activities shape mammal communities globally, revealing the drivers of the loss of larger predators in human- modified landscapes.Human activity and land use change are driving declines in many animal species while benefiting others, but predicting which species will successfully coexist with humans remains a challenge. We compiled detection data for 24 mammal species from 61 populations across North America and showed that species life history traits were strong predictors of their responses to human footprint (landscape modification), with increasing footprint favoring smaller, less carnivorous, faster- reproducing species. Positive and negative effects of direct human presence (e.g., recreation, hunting) were distributed more randomly across species, with apparent winners and losers across a range of body sizes and dietary guilds.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168486/1/gcb15650.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168486/2/gcb15650_am.pd

Disturbance type and species life history predict mammal responses to humans

Human activity and land use change impact every landscape on Earth, driving declines in many animal species while benefiting others. Species ecological and life history traits may predict success in human- dominated landscapes such that only species with - winning- combinations of traits will persist in disturbed environments. However, this link between species traits and successful coexistence with humans remains obscured by the complexity of anthropogenic disturbances and variability among study systems. We compiled detection data for 24 mammal species from 61 populations across North America to quantify the effects of (1) the direct presence of people and (2) the human footprint (landscape modification) on mammal occurrence and activity levels. Thirty- three percent of mammal species exhibited a net negative response (i.e., reduced occurrence or activity) to increasing human presence and/or footprint across populations, whereas 58% of species were positively associated with increasing disturbance. However, apparent benefits of human presence and footprint tended to decrease or disappear at higher disturbance levels, indicative of thresholds in mammal species- capacity to tolerate disturbance or exploit human- dominated landscapes. Species ecological and life history traits were strong predictors of their responses to human footprint, with increasing footprint favoring smaller, less carnivorous, faster- reproducing species. The positive and negative effects of human presence were distributed more randomly with respect to species trait values, with apparent winners and losers across a range of body sizes and dietary guilds. Differential responses by some species to human presence and human footprint highlight the importance of considering these two forms of human disturbance separately when estimating anthropogenic impacts on wildlife. Our approach provides insights into the complex mechanisms through which human activities shape mammal communities globally, revealing the drivers of the loss of larger predators in human- modified landscapes.Human activity and land use change are driving declines in many animal species while benefiting others, but predicting which species will successfully coexist with humans remains a challenge. We compiled detection data for 24 mammal species from 61 populations across North America and showed that species life history traits were strong predictors of their responses to human footprint (landscape modification), with increasing footprint favoring smaller, less carnivorous, faster- reproducing species. Positive and negative effects of direct human presence (e.g., recreation, hunting) were distributed more randomly across species, with apparent winners and losers across a range of body sizes and dietary guilds.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168486/1/gcb15650.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168486/2/gcb15650_am.pd