Treesearch

Ecological theory predicts that animals will select habitats for breeding that confer an adaptive advantage through increased reproductive success. We therefore expect to see congruence between habitat preferences and measures of fitness. We studied abundance, nest site selection, and nest survival in white-headed woodpeckers (Picoides albolarvatus) in four forest types along an elevational gradient in the southern Sierra Nevada, California. Our primary objective was to ascertain what habitat features white-headed woodpeckers were selecting for nesting and at what scale, and whether those...

Forward thinking conservation-planning can benefit from modeling future landscapes that result from multiple alternative management scenarios. However, long-term landscape modeling and downstream analyses of modeling results can lead to massive amounts of data that are difficult to assemble, analyze, and to report findings in a way that is easily accessible to decision makers. In this study, we developed a decision support process to evaluate modeled forest conditions resulting from five management scenarios, across 100 years in California’s Lake Tahoe basin; to this end we drew upon a...

Effective forest management, particularly during forest disturbance events, requires timely and accurate monitoring information at appropriate spatial scales. In Hawai‘i, widespread ‘ōhi‘a (Metrosideros polymorpha Gaud.) mortality associated with introduced fungal pathogens affects forest stands across the archipelago, further impacting native ecosystems already under threat from invasive species. Here, we share results from an integrated monitoring program based on high resolution (<5 cm) aerial imagery, field sampling, and confirmatory laboratory testing to detect and monitor ‘ōhi‘a...

With 27 years of data (1986–2012), we examined long-term patterns of variation in abundance and population trends for 35 species of oak woodland birds. Following a standardized protocol, from three to eight observers counted birds annually at 210 count stations at the San Joaquin Experimental Range, Madera County, California. We used both linear regression and nonparametric regression (spline-smoothing the year effect) to evaluate population trends. The abundance of most species varied greatly over the study period, emphasizing the importance of long-term monitoring. Overall, 12 species...

Identifying the potential for natural soil microbial communities to predictably affect complex plant traits is an important frontier in climate change research. Plant phenology varies with environmental and genetic factors, but few studies have examined whether the soil microbiome interacts with plant population differentiation to affect phenology and ecosystem function. We compared soil microbial variation in a widespread tree species (Populus angustifolia) with different soil inoculum treatments in a common garden environment to test how the soil microbiome affects spring foliar phenology...

Mechanistic, individual-based simulation models have been used for >25 years to overcome well-known limitations of “habitat suitability” models. InSTREAM 7 is the latest of our individual-based models for predicting the effects of flow and temperature regimes on stream salmonid populations. Unlike PHABSIM (or other methods based on habitat “quality,” e.g., as net rate of energy intake), inSTREAM mechanistically represents specific effects of flow and temperature on all life stages, and how those effects combine into testable predictions of population measures such as abundance, relative...

1. The removal and exclusion of non-native ungulates for conservation of biodiversity is common globally, including on tropical Pacific Islands. However, the poorly quantified effects of ungulate exclusion on fuels and wildfire may represent an important conservation trade-off. 2. We measured fuels (live and dead fuel loads, type, height and continuity) and modelled potential wildfire behaviour (flame height and rate of spread) inside and outside of 13 ungulate exclosures, three of which received active ecological restoration (e.g. planting of native shrubs and trees), across a 2,740 mm...

Aim Habitat suitability modelling methods for presence-only species data are limited in their ability for making true predictions and are therefore often misused in ecological applications. A use-availability design—also known as a case–control design with contaminated controls—combines presence-only species data with a background sample of covariates where the species presence/absence is unknown. Assuming a log link function for the true probability of presence/absence, the use-availability data then can be analysed as a logistic regression model with a biased estimate of the intercept....

A critical step in the development of a postfire restoration strategy is the acquisition and analysis of relevant data and other information. This information is essential to answering questions posed in the postfire flowchart that, in turn, informs the restoration portfolio (both addressed in chapter 2). Spatially explicit information helps us to evaluate the ecological condition of a postfire landscape, including the capacity of a particular area to support ecosystems in the future and the ecological processes that may affect ecosystem succession. Acquired and analyzed at a meaningful...

Mixed-conifer forests are widely distributed throughout the mountainous regions of California, occurring just below the upper montane elevation belt and typically ranging from 1,000 to 7,000 ft (300 to 2000 m). Common tree species include ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and Jeffrey pine (P. jeffreyi Balf.), white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.), sugar pine (P. lambertiana Douglas), incense cedar (Calocedrus decurrens (Torr.) Florin), Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), and black oak (Quercus kelloggii Newberry), and there are...