ABSTRACT Aim Global conservation assessments recognize the mediterranean biome as a priority for of world's biodiversity. To better direct future efforts in biome, an improved understanding location, magnitude and trend key threats their relationship with species importance is needed. Location Mediterranean‐climate regions California‐Baja California, Chile, South Africa, Australia Mediterranean Basin. Methods We undertook systematic, pan‐regional assessment including human population...

Fire is one of the most important natural disturbance processes in western United States and ecosystems differ markedly with respect to their ecological evolutionary relationships fire. Reference fire regimes forested can be categorized along a gradient ranging from “fuel‐limited” “climate‐limited” where former types are often characterized by frequent, lower‐severity wildfires latter infrequent, more severe wildfires. Using spatial data on severity 1984–2011 metrics related frequency, we...

Unique properties of nanomaterials can be leveraged to increase the sustainability food production and distribution.

Building on previous environmental flow discussions and a growing recognition that hydrogeomorphic processes are inherent in the ecological functionality biodiversity of riverscapes, we propose functional-flows approach to managing heavily modified rivers. The focuses retaining specific process-based components hydrograph, or functional flows, rather than attempting mimic full natural regime. Key include wet-season initiation peak magnitude recession dry-season low interannual variability....

Abstract Rising evaporative demand (ETo) with a warming climate contributes to diminished water availability in water-stressed agricultural regions globally. While increased ETo typically necessitates irrigation, we explore how crop phenological response can moderate this challenge. Focusing on five key crops California’s San Joaquin Valley, employ coupled balance and phenology models project demands as function of changing phenology. All exhibited accelerated growth from shortened growing...

Nathaniel E. Seavy, Thomas Gardali, Gregory H. Golet, F. Griggs, Christine A. Howell, Rodd Kelsey, Stacy L. Small, Joshua Viers and James Weigand

We asked how the richness of specialized (endemic) flora serpentine rock outcrops in California varies at both regional and local scales. Our study had two goals: first, to test whether endemic is affected by spatial habitat structure (e.g., area, outcrop measures isolation), second, conduct this context a broader assessment environmental influences climate, soils, vegetation, disturbance) historical geologic age, geographic province) on species richness. measured total variables 109 sites...

Abstract Freshwater ecosystems and their associated biota are among the most endangered in world. This, combined with escalating human pressure on water resources, demands that urgent measures be taken to conserve freshwater services they provide. Systematic conservation planning provides a strategic scientifically defensible framework for doing this. Pioneered terrestrial realm, there has been some scepticism applicability of systematic approaches planning. Recent studies, however, indicate...

Invasive species are one of the fastest growing conservation problems. These homogenize world's flora and fauna, threaten rare endemic species, impose large economic costs. Here, we examine distribution 834 more than 1000 exotic plant taxa that have become established in California, USA. Total richness increases with net primary productivity; however, is richest low-lying coastal sites harbor numbers imperiled while native diversity highest areas high mean elevation. Weedy invasive exotics...

We present a summary of database documenting levels affinity to ultramafic (“serpentine”) substrates for taxa in the California flora, USA. constructed our through an extensive literature search, expert opinion, field observations, and intensive use accession records at key herbaria. developed semi-quantitative methodology determining serpentine (strictly endemic, broadly strong “indicator”, etc.) flora. In this contribution, we provide list having high ultramafic/serpentine California,...

Acute changes in ecological disturbance regimes can have major consequences for ecosystems and biota, including humans, living within them. Human suppression of fire the western United States over last century has caused notable to many ecosystems, especially lower elevation, semiarid forest types dominated historically by tolerant taxa like Pinus Quercus . Recent increases activity US forests highlighted need restoration structure function, but management targets different remain uncertain....

This study focuses on the differential hydrologic response of individual watersheds to climate warming within Sierra Nevada mountain region California. We describe models for 15 west-slope in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental alternatives increase air temperature uniformly by 2 degrees, 4 and 6 degrees C, but leave other climatic variables unchanged from observed values. Results are analyzed changes mean annual...

Abstract With some of the highest biodiversity on planet, Mediterranean Biome is experiencing a conservation crisis driven by high human population density, development, and habitat fragmentation. While protected areas safeguard critical habitat, economic realities require efforts in human‐dominated landscapes to maintain practice. As an essential component food security for growing population, agricultural must play key role such because they occupy large land, are adjacent both depend...

For 100 years, California's State Water Resources Control Board and its predecessors have been responsible for allocating available water supplies to beneficial uses, but inaccurate incomplete accounting of rights has made the state ill-equipped satisfy growing societal demands supply reliability healthy ecosystems. Here, we present first comprehensive evaluation appropriative identify where, what extent, dedicated human uses relative natural supplies. The results show that right allocations...

An important goal of invasion biology is to identify physical and environmental characteristics that may make a region particularly receptive invasions. The inland waters California (USA) are highly invaded, by fishes, although there wide variation in numbers nonnative fishes across the state's watersheds. Here we examine patterns fish invasions watersheds their associations with natural characteristics, native diversity, various measures human habitat disturbance. Our analysis based on an...

The ability to measure vegetation structure at spatial scales that are biologically meaningful for wildlife is often limited because information about the scale of habitat selection lacking and there logistical constraints measuring ever larger scales. To address this challenge, we used LiDAR-derived measurements canopy height quantify associations riparian birds Cosumnes River Preserve in central California, USA. Our objectives were (1) evaluate utility LiDAR (light detection ranging)...

We present a conceptual model for the ecology of spring snowmelt recession based on natural flow regime that relates quantifiable components magnitude, timing, and rate change to abiotic biotic factors govern riverine processes. find shifts in magnitude largely affect channel conditions, whereas timing primarily conditions. Shifts both creating largest observed changes stream ecosystem. discuss these with regard success species California's Mediterranean-montane environment. then two...

At small scales, areas with high native diversity are often resistant to invasion, while at large more species harbor exotic species, suggesting that different processes control the relationship between and spatial scales. Although small-scale negative has a satisfactory explanation, we lack mechanistic explanation for change in positive We investigated native–exotic three scales (range: 1–4000 km2) California serpentine, system wide range productivity of sites from harsh lush. Native were...

Abstract This article provides a method for examining mesoscale water quality objectives downstream of dams with anticipated climate change using multimodel approach. Coldwater habitat species such as trout and salmon has been reduced by regulation, dam building, land use that alter stream temperatures. Climate is an additional threat. Changing hydroclimatic conditions will likely impact temperatures below affect ecology. We model reservoir thermal dynamics release operations (assuming...

Viers, Joshua H., 2011. Hydropower Relicensing and Climate Change. Journal of the American Water Resources Association (JAWRA) 47(4):655-661. DOI: 10.1111/j.1752-1688.2011.00531.x Abstract: represents approximately 20% world's energy supply, is viewed as both vulnerable to global climate warming an asset reduce climate-altering emissions, increasingly target improved regulation meet multiple ecosystem service benefits. It within this context that recent decision by United States Federal...