Treesearch

Given the uncertain population status of low-density, widely-occurring raptors, monitoring changes in abundance and distribution is critical to conserving populations. Nest-based monitoring is a common, useful approach, but the difficulty and expense of monitoring raptor nests and importance of reliable trend data to conservation requires that limited resources are allocated efficiently. Power analyses offer a helpful tool to ensure that monitoring programs have the ability to detect trends and to optimize financial resources devoted to monitoring. We evaluated alternative monitoring...

Respiration is as essential to plants as it is to animals. Because respiration increases exponentially in response to temperature in the short term, models predict that higher temperatures would lead to higher plant respiration losses, yielding less carbohydrate supply for growth and reproduction. Also because the short-term temperature response is exponential, respiration has been suggested as the cause of slower growth in warmer conditions in field studies (Clark et al., 2003). However, many studies have shown acclimation of respiration, where respiration rates of plant tissues at a...

Soil organic carbon (SOC) is a large reservoir of terrestrial carbon (C); it consists of different fractions of varying complexity and stability. Partitioning SOC into different pools of decomposability help better predict the trend of changes in SOC dynamics under climate change. Information on how physical fractions and chemical structures of SOC are related to climate and vegetation types is essential for spatial modelling of SOC processes and responses to global change factors.

Estimating population abundance of wolves (Canis lupus) in densely forested landscapes is challenging because reduced visibility lowers the success of methods such as aerial surveys and enumeration of group size using radiotelemetry. However, regular population estimates of wolves are necessary for population monitoring and sustainable management. We used noninvasive hair snaring and spatially explicit capture-recapture (SECR) to estimate wolf abundance on Prince of Wales Island (POW), Alaska, USA, during 2012-2015. We monitored 36-82 hair‐snare stations weekly for 9-11 weeks during...

Armillaria altimontana and A. solidipes frequently co-occur (McDonald et al. 2000) and are commonly found in association with western white pine (Pinus monticola). Armillaria solidipes (as A. ostoyae) is well-known as a virulent primary pathogen on diverse conifers within inland western regions of the contiguous USA (Lockman and Kearns 2016), whereas A. altimontana is considered to be a weak or secondary pathogen (Brazee et al. 2012). However, little has been documented about the impact of A. altimontana on tree health and growth.

We performed experiments in southwestern USA streams to evaluate the efficacy of environmental DNA (eDNA) sampling for two rare small-bodied minnows: Spikedace Meda fulgida and Loach Minnow Rhinichthys cobitis. We collected eDNA by filtering 5-L samples and compared detection sensitivity of eDNA assays to traditional sampling methods (electrofishing and seining) by using both techniques at 33 sites in seven streams. We used caged-fish experiments to estimate eDNA production rates, persistence, and travel distances and to estimate relationships between fish density, biomass, and eDNA...

Armillaria species are key components of forest ecosystems throughout most regions of western North America. Their ecological roles range from beneficial saprobes to damaging root pathogens, and their impacts vary with environment and host. Under climate change, the impact of pathogenic species within these regions is predicted to increase (Kliejunas et al 2009), which could result in increased tree mortality, growth loss, and hazard trees that threaten public safety. In 2016, a collaborative project was initiated to survey of Armillaria spp. distributions in western Oregon, western...

Armillaria root disease causes extensive damage to tree roots throughout the world, but efficacious management practices are lacking. However, soil interactions among Armillaria species, microbial communities, and trees may determine the impact of pathogenic Armillaria on the growth and survival of trees. Two species, A. solidipes (highly virulent) and A. altimontana (less virulent), frequently co-occur in forests of inland northwestern USA. Soil metagenomics and metatransciptomics may provide key insights into how interactions among soil microbial communities and root pathogens influence...

Expectations of the impacts of climatic variation on species can depend on whether and how intraspecific variability is incorporated in models. Coefficients of variation from tree-ring records of Pinus albicaulis through time and across space were used to parameterize volatility and individuality, respectively. The records across sites were used to differentiate the average modes on an environmental gradient for Gaussian fitness of ecotypic niches, and to add further individual variation in mode and standard deviation of these functions in individual-based Monte Carlo simulations of...

Koa (Acacia koa Gray) is an endemic, keystone species in Hawai’i’s forests. Koa is valuable economically (contributed $30 million to Hawai’i’s forestry industry in 2001), ecologically (habitat for many endangered birds and insects), and culturally (koa is the main wood used for making Hawaiian canoes). Mortality of koa trees due to koa wilt (caused by Fusarium oxysporum f. sp. koae; Foxy-koae) has been increasing, primarily in the low- to mid-elevation forests (Gardner 1980). Fusarium oxysporum (Foxy) is an important vascular wilt pathogen of many plant species worldwide (Leslie 2006)....