Microhistology of moose browse using polarized light microscopy and age & sex-determination using moose scat

<p> Amphibians are important bioindicators in environmental assessment. This highly diverse group of vertebrates is experiencing unprecedented declines worldwide due to a complex array of factors, including disease, habitat loss, invasive species, and environmental pollution. Heavy metals are especially problematic due to their persistence and ability to present a localized hazard even at sublethal levels. Northern Idaho has a long history of mining activity, and many watersheds have experienced heavy metal contamination. These streams contain many sensitive species, including the Rocky Mountain Tailed Frog, <i> (Ascaphus montanus)</i>. While tailed frog populations are known to be especially vulnerable to logging and road building, the effects of local mining have not been documented. In order to assess the vulnerability of this species to heavy metal contamination, tadpoles were collected from three distinct populations across the Idaho Panhandle National Forest. Two sampling sites (Gold Creek and Beauty Creek) were characterized by abandoned mines in the headwaters of the streams, while a stream absent of any local historic mining (Bumblebee Creek) served as a reference site. Whole tadpoles were pooled and treated using EPA Method 3050B and analyzed for dissolved metal concentration (ug/g) using ICP-MS. We found the average metal concentrations in tadpoles (ug/g) at mining sites were generally higher than the reference site. Cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) were significantly higher in tadpoles at Gold Creek when compared with the reference site. These results are consistent with other studies indicating metals from historic mining activity are still evident in these stream communities.</p>

<p> Amphibian species have experienced global declines since the 1970s and plethodontid salamanders are no exception. The green salamander, <i> Aneides aeneus,</i> is a plethodontid salamander that has experienced declines throughout its range in the Blue Ridge Escarpment. </p><p> Species distribution models are algorithms that predict occurrences of a species across a landscape and can be used to determine conservation priority areas. However, there are commonly only presence locations without corresponding absence locations available to a researcher. These presence-only datasets can present a challenge when trying to depict reliable distributions for a species of concern. Maximum Entropy (MaxEnt) is an algorithm empirically tested to model species distributions given presence-only datatsets. </p><p> I used landscape-level species distribution models including MaxEnt and logistic regression to model the occurrence of green salamanders across the Blue Ridge Escarpment of North Carolina. These models were used to assess particular features associated with <i>A. aeneus</i> presence as well used to search for new localities. </p><p> MaxEnt models outperformed logistic regressions for all methods of evaluation. MaxEnt models had fairly low omission (false negative) and commission (false positive) rates whereas my logistic regression had extremely high error rates for both. "Area Under the Receiver Operator Curve" evaluation scores were excellent (0.96) and good (0.81) for the top Maxent model and logistic regression, respectively. </p><p> <i>Aneides aeneus</i> is known to be associated with habitat that includes rock outcroppings with thin, deep crevices. My models indicated that forested areas, intermediate elevations, and shallow soils of particular types are desirable landscape features for <i>A. aeneus.</i> Soil was the most important variable in all models, accounting for almost half of the variation in MaxEnt models. Elevation accounted for most of the remaining variation. Percent canopy cover accounted for 4-6.5% of the variation in Maxent models. While these models did not specifically predict presence of outcrops, they were extremely helpful in identifying habitat with conditions supportive for <i>A. aeneus</i> if a rock outcrop was present. With the help of these models I discovered one previously unknown locality for <i> A. aeneus</i> and am confident addition locations can be found.</p>

For purposes of conservation, we require methods to predict where species occur currently, and where they are likely to move in the future. Species distribution models can be useful tools, by predicting where species are in areas that cannot be surveyed but where management decisions must occur. However, they are rarely tested using independent field surveys to determine their accuracy. These models are also generally developed over broad spatial scales; in contrast, distributions must often be predicted over local to regional scales for conservation purposes. Using butterfly surveys along transects in eastern Ontario, we tested whether independent regional observations of butterflies could be predicted from distribution models developed on Canada-wide species ranges. We also developed a set of regional models using Maximum entropy software to compare with the independent field surveys. Our results show that regional field occurrences are not accurately predicted by the national models, which explain between 0 and 31% (median 4.2%) of the deviance in species presence/absence. Even when species distribution models developed using regional variables have high apparent accuracy (AUC values exceed 0.8), they do not appear to accurately predict occurrence at local spatial extents, explaining between 0 and 46% (median 3.4%) of the deviance in species presence/absence. Species distribution models' inaccuracy in predicting species' presence within their ranges indicates that field-based observations remain indispensable when making conservation decisions. Misusing models can be costly if they lead to errors in predicting the presence of species of concern or their habitat and can result in poor management decisions if used improperly.

<p>The efficacy of intensive rotational targeted grazing (IRTG) for suppression of the invasive shrub, multiflora rose (Rosa multiflora) was investigated in upstate New York. Sheep stocked at high density were rotated through a circuit of enclosures at a frequency of 3-d per enclosure, from May-September, 2011 and 2012. The photosynthetic surface areas (PSA) and vitality of R. multiflora plants were evaluated before (May 2011) and after treatment by grazing (Sept 2011). Changes over time were compared with similar measurements of ungrazed plants. Species richness (S) was estimated in each enclosure before (May) and after (September) treatment. PSA in grazed enclosures declined by 56.8% over the 2011 season and by 62.5% during the 2012 season. One year after ITRG treatment, healthy R. multiflora plants in grazed enclosures had declined by 91% and unhealthy and dead plants had increased by more than 200%. The distributions of healthy, unhealthy and dead plants, in grazed and ungrazed enclosures, though not different before treatment (chi square goodness of fit test; p>0.05?? were different one year later (p<0.001). Mean S in grazed enclosures increased by 27% over the season and by the end of the study, S was 12% higher than ungrazed enclosures. Evidence of stress in R. multiflora (clumping, dwarfing and reddening of leaves) at the end of the 2011 season led me to investigate the possible presence of rose rosette disease (RRD) during 2012. Potential stress was confirmed in plants experiencing leaf reddening. Chlorophyll a concentrations were significantly lower in red than green leaves (Student?s t = 5.20, df=28, p<0.001). Not unexpectedly, Normalized Difference Vegetative Index (NDVI) lso differed in red and green leaves (Student?s t = 2.76, df=32, p<0.01). Green leaves had higher dry weights than red leaves (Student?s t=14.13, df=151, p<0.001). Wool from the sheep, and R. multiflora leaf and petiole samples were collected to determine if the eriophyid mite, Phyllocoptes fructiphilus, a vector for RRD was present. No significant evidence of P. fructiphilus in leaf and petiole (Mean=0.00 N=414 SD=.71) or wool samples (Mean=0.00 N=11 SD=0) was found. This was unexpected, although it would only take one mite to be the vector if that particular mite was carrying the rose rosette virus. Further studies would be required to test whether rose rosette was confirmed in this population. Visual evidence of RRD symptoms were more prevalent in grazed enclosures than ungrazed locations, and a greater decline in grazed enclosures was clear.

This dissertation addresses the question of the sustainability of the current dynamics of bushmeat hunting by local communities in there Serengeti ecosystem as well as attempt to understand the preferences and demand for animal protein in these households, and finally to test the potential for reducing demand for bushmeat through an intervention measure aimed at improving access to alternative protein sources. In this dissertation, I use a multi-faceted approach to explore the current drivers of bushmeat hunting in the Greater Serengeti Ecosystem, and attempt to quantify the real threat to wildlife populations. Utilizing dietary recall consumption surveys, household socio-economic questionnaires, I integrate almost ideal demand systems analysis and evaluate the impact of protein alternatives in reducing consumption of bushmeat.

<p> Habitat use by federally threatened California Red-Legged Frogs (CRLF; <i>Rana draytonii</i>) is incompletely understood. I captured, PIT-tagged, and radio-tracked CRLFs (n = 20) at Waddell Creek, Santa Cruz County, from July&ndash;December 2012. Limited tracking for movements was also conducted in 2013. Frogs were clumped in deep, complex habitats along the stream within 2 km of breeding ponds near the stream mouth, but most adults were concentrated in the lagoon. Marked and tracked frogs had very small summer home ranges, and most returned to the same home range after breeding. Frogs tended to use good aquatic (e.g., wood, undercut banks, dense willows) and bank cover (e.g., ground vegetation, wood) at all times but used open habitats more at night than during the day. Visual night surveys were biased against cryptic frogs compared to radio-tracking results. Early fall rains increased upland habitat use, but later heavy winter rains were needed to trigger migration to breeding sites and subsequent breeding. Site-specific studies using radio-tracking are needed to design protections for breeding, migration, and nonbreeding habitats.</p>

<p> Very little information is available on the Hawaiian Oyster <i> Dendostrea sandvicensis</i> in regards to its biology and physiology. Efforts were made to better understand the active reproductive season of this oyster by studying the population located in He'eia fish pond in Kaneohe Bay, O`ahu. This study focused on the condition index (CI) and gonadal developmental stage trends, measured from monthly oyster tissue samples from January to December 2009. The relationship between CI and temperature was examined. Results suggest CI is not related to temperature. Further analysis defined a positive correlation for CI and temperature during summer but not in winter. Ranges in CI values were higher in summer than in winter. <i>D. sandvicensis </i> experience a tropical reproductive cycle, as trends related to the gonadal stage indicate. January to March is dominated by maturing gonads. From April to October there is a rise and then steady decline of empty gonads indicating an active reproduction season. From November to December a rise in mature gonads indicate readiness for reproduction and recovery. Empty gonads are present through out the year indicating reproduction happens throughout the year, and peaks in beginning of summer.</p>

<p> Terrestrial litterfall is a well-documented subsidy of nutrients and organic matter to adjacent aquatic ecosystems. Nitrogen-fixing plants increase nutrient dynamics via nitrogen (N) - rich litterfall in both terrestrial and aquatic ecosystems, and the effects are often more pronounced when areas lacking native N₂-fixers are invaded. This study examined differences in organic matter and nutrient inputs from the invasive, N₂-fixing tree, <i>Prosopis pallida</i>, and the native, non N₂-fixing tree, <i>Thespesia populnea</i>, to determine effects on anchialine ponds on Hawai`i Island's leeward coast. My objectives were to quantify: 1) tree basal area and density surrounding the ponds, 2) quality and quantity of <i>P. pallida</i> and <i>T. populnea</i> litter inputs, 3) inorganic N content of soil surrounding the ponds, 4) leached nutrients from <i>P. pallida</i> and <i>T. populnea</i> leaf litter. These response variables were then compared to water nutrient concentrations (i.e., phosphate, nitrate, ammonium, dissolved organic carbon (C), and total dissolved N and phosphorus (P)) in the ponds of interest. Basal area, density, litterfall mass, total N and C inputs, and leachate values were similar between pond types categorized as <i>P. pallida</i> &ndash; or <i> T. populnea</i> &ndash; dominated. Foliar N concentrations were 28 percent higher in <i>P. pallida</i> &ndash; dominated ponds compared to <i>T. populnea</i> &ndash; dominated ponds, but foliar P concentrations were three times greater in <i>T. populnea</i> ponds than <i>P. pallida</i> ponds. Total P inputs were greater beneath <i>T. populnea</i> ponds and there was a positive correlation between <i>T. populnea</i> size and abundance and pond water phosphate concentrations. These results suggest that the N if influencing water quality in Hawaiian anchialine ponds more than the invasive N₂-fixing species, although high background water nutrient levels may be inhibiting our ability to detect any significant impacts. The transfer of <i>T. populnea</i>'s P-rich litter to pond water appears to have a strong influence on ecosystem functioning.</p>

<p> The Zayante sandhills ecosystem of Santa Cruz County, California, contains a rich mosaic of plants and animals adapted to unusual soils and microclimates. In this environment, local adaptation of populations is expected to lead to greater endemism and outbreeding depression. Anthropogenic fragmentation has further isolated populations, however, which paradoxically could result in inbreeding depression. One of these plants, <i>Erysimum teretifolium </i> (Ben Lomond wallflower) is an endangered endemic herb in the Brassicaceae family. This study assessed genetic mixing across remnant patches of <i> E. teretifolium</i> in order to estimate the effects of fragmentation and the reliance on pollinators. A captive breeding colony was established from seeds collected from four locations across the Zayante sandhills and used in 161 pollinations. Individual allele frequencies were measured using microsatellites, and pollination potential was evaluated through insect camera trapping. Self-pollinations produced 6.5 times fewer seeds than outcrosses. There is no evidence of outbreeding depression. Results suggest that there is a potential for inbreeding depression; however, it is possible that self-incompatibility and reliance on pollinators for outcrosses across geographic divides may be buffering effects. Implications for managers include evidence that geographic origin of individuals may not be critical for reintroduction; however, conservation of the pollinator community should remain a priority.</p>