Treesearch

Fine and coarse woody debris (WD), or woody necromass, serves a multitude of functions in forests including: essential habitat for countless vertebrate, arthropod and microbial species; substrate for regenerating plants, for example as nurse logs; a dominant carbon source for heterotrophs; and both a sink and source for essential nutrients (Harmon et al. 1986; Palace et al. 2012). Further, as WD decomposes, resulting fragments and microbial byproducts of the decay process provide a major source of organic matter for soils (Magnússon et al. 2016). Finally, WD can account for up to 20% of...

In California, projections of intensifying wet-dry extremes and shifts in precipitation seasonality suggest that hydrologic droughts may become more frequent in the coast redwood region. An increase in hydrologic drought frequency may be particularly problematic for aquatic species that rely on flow in headwater streams during the region’s June-October dry season. We used a 55-year record of precipitation and streamflow to explore the relationship between meteorological drought and hydrologic drought in the Caspar Creek Experimental Watersheds in north coastal California. The 4.24- km2...

Accurate estimates of growth and structural changes are key for forest management tasks such as determination of optimal rotation times, optimal rotation times, site indices and for identifying areas experiencing difficulties to regenerate. Estimation of structural changes, especially for biomass, is also key to quantify greenhouse gas (GHG) emissions/sequestration. We compared two different modeling strategies to estimate changes in V, BA and B, at three different spatial aggregation levels using auxiliary information from two light detection and ranging (LiDAR) flights. The study area is...

Selection of habitat characteristics by reproductive females during neonate development can mediate the influence of adverse environmental conditions on the fitness of offspring. Previous research has suggested that cavities and burrows used for reproduction by cavity-obligate species offer thermoregulatory benefits, access to prey, and can limit predation pressure. As fishers (Pekania pennanti) are secondary cavity-obligate breeders, we hypothesized that they select particular characteristics of reproductive den cavities at discrete stages of offspring development to mediate adverse...

Fuel continuity is the degree or extent of continuous or uninterrupted distribution of fuel particles in a fuel bed thus affecting a fire’s ability to sustain combustion and spread. This applies to ladder fuels as well as surface fuels (NWCG 2018).

The Sierra Nevada yellow‐legged frog (Rana sierrae) was once an abundant and widely distributed amphibian in California's alpine ranges. Rana sierraeis adapted to high‐elevation, fishless habitats. Its adaptions are reflected in a unique life cycle that involves a flexible, extended juvenile phase due to the short growing season typical of its alpine habitat. However, today this species is critically endangered, and most populations have been extirpated from their native range. Here, we present an 18‐yr‐long demographic study of a R. sierraepopulation in 15 lakes at Dusy Basin in Kings...

Streamflow is a main driver of fish population dynamics and is projected to decrease in much of the northern hemisphere, especially in the Mediterranean region, due to climate change. However, predictions of future climate effects on cold-water freshwater fish populations have typically focused only on the ecological consequences of increasing temperatures, overlooking the concurrent and interacting effects of climate-driven changes in streamflow regimes. Here, we present simulations that contrasted the consequences of changes in thermal regime alone versus the combined effects of changes...

Disturbances are part of the natural dynamics of Earth's ecosystems, with these events more common now in the Anthropocene. Yet metrics for calibrating these impacts and measuring an ecosystem's capacity to recover are lacking. Highway construction in 1989 to bypass Prairie Creek Redwoods State Park in California resulted in storm‐driven infusion of exposed sediments into five streams; five nearby streams that were not intersected by the bypass construction were not affected by this event and served as controls for a natural experiment. A second large storm event in 1995 contributed...

Stream classifications can be used to understand patterns within and across river networks and are most informative when they offer insight into patterns in stream habitat or biology. We developed a classification of Hawaiian stream reaches based on influences of natural landscape features on distributions of stream organisms to understand patterns in ecological potential across five Hawaiian Islands. Our objectives were to (1) identify natural landscape variables strongly associated with species distributions and likely to affect stream habitat; and (2) classify Hawaiian stream reaches...

The relative contribution of private and public forest to the conservation of species in mixed-ownership landscapes has often been contentious because management goals vary among owners. This tension can be exacerbated by a lack of understanding about how wildlife use habitats managed by different landowners and the relative value of habitats in having different structures, configurations, and management histories. To address this knowledge gap and enhance science-based conservation planning among different ownerships, we analyzed habitat selection by 53 GPS-tagged California spotted owls...