820 research outputs found
Lassen Volcanic National Park Small Vertebrate Inventory Project: Preliminary Results 2000-2004
Biologists at Lassen Volcanic National Park in northern California conducted an inventory of non-flying small mammals, amphibians and reptiles from 2000 through 2004. The four primary habitat types in the park (brush, forest, riparian and subalpine) were each sampled at one high elevation and one mid-elevation site in the park. Each of the eight sites was sampled for four six-day periods between June and September each year using a combination of pitfall, Sherman and Tomahawk traps, coverboards and unbaited automatic camera stations. This effort yielded 12,150 captures and 776 photo detections. A total of 649 voucher specimens, representing 19 mammal, one amphibian and two reptile species, was collected and accessioned to the Museum of Vertebrate Zoology at the University of California, Berkeley
A Cost-Effective Method for Applying and Removing Bird-Exclusion Netting in Commercial Vineyards
Bird-exclusion netting can be highly effective for reducing bird damage to agricultural crops, but the high cost of materials and perceived difficulty of applying and removing it has discouraged many growers from using this technique. The expectation of extensive damage to a high-value crop may warrant the implementation of costly protection measures such as bird-exclusion netting. During 1987, we evaluated a method for applying and removing bird-exclusion netting in 4 commercial vineyards on the North Fork of Long Island, New York. The method involved altering a hydraulically-operated, front-end bucket-loader to accommodate loading and applying 5.2-m-wide nets directly over rows of grape vines. Applying the netting, including loading and unloading the rolls of netting, required an average of 2.5 hr/ha for 3 people. Removal required an average of 2.8 hr/ha for 3 people. The single largest cost was the price of the netting, which accounted for approximately 70-74% of the total cost of the program. Four growers have used the netting for 5 seasons with minimal damage and anticipate using the netting for at least 1 additional season. The total cost of modifying the tractor and purchasing, applying, and removing the netting, based on an estimated net life of 5 yr, was 534/ha/yr. Assuming that the netting is 95% effective in preventing bird depredations, it provides cost-effective protection in vineyards where high levels of damage ( \u3e 6%) are anticipated. However, the netting may not be practical in small vineyards or where low levels of damage are expected. An increasing number of vineyard managers on Long Island are using bird-exclusion netting to protect their vineyards from birds
Sustaining Economic Exploitation of Complex Ecosystems in Computational Models of Coupled Human-Natural Networks
Understanding ecological complexity has stymied scientists for decades. Recent elucidation of the famously coined "devious strategies for stability in enduring natural systems" has opened up a new field of computational analyses of complex ecological networks where the nonlinear dynamics of many interacting species can be more realistically mod-eled and understood. Here, we describe the first extension of this field to include coupled human-natural systems. This extension elucidates new strategies for sustaining extraction of biomass (e.g., fish, forests, fiber) from ecosystems that account for ecological complexity and can pursue multiple goals such as maximizing economic profit, employment and carbon sequestration by ecosystems. Our more realistic modeling of ecosystems helps explain why simpler "maxi-mum sustainable yield" bioeconomic models underpinning much natural resource extraction policy leads to less profit, biomass, and biodiversity than predicted by those simple models. Current research directions of this integrated natu-ral and social science include applying artificial intelligence, cloud computing, and multiplayer online games
Addressing biased occurrence data in predicting potential Sierra Nevada red fox habitat for survey prioritization
The Sierra Nevada red fox Vulpes vulpes necator is listed as a threatened species under the California Endangered Species Act. It originally occurred throughout Californiaâs Cascade and Sierra Nevada mountain regions. Its current distribution is unknown but should be determined in order to guide management actions. We used occurrence data from the only known population, in the Lassen Peak region of northern California, combined with climatic and remotely sensed variables, to predict the speciesâ potential distribution throughout its historic range. These model predictions can guide future surveys to locate additional fox populations. Moreover, they allow us to compare the relative performances of presence-absence (logistic regression) and presence-only (maximum entropy, or Maxent) modeling approaches using occurrence data with potential false absences and geographical biases. We also evaluated the recently revised Maxent algorithm that reduces the effect of geographically biased occurrence data by subsetting background pixels to match biases in the occurrence data. Within the Lassen Peak region, all models had good fit to the test data, with high values for the true skill statistic (76â83%), percent correctly classified (86â92%), and area under the curve (0.94â0.96), with Maxent models yielding slightly higher values. Outside the Lassen Peak region, the logistic regression model yielded the highest predictive performance, providing the closest match to the foxâs historic range and also predicting a site where red foxes were subsequently detected in autumn 2010. Subsetting background pixels in Maxent reduced but did not eliminate the effect that geographically biased occurrence data had on prediction results relative to the Maxent model using full background pixels
Sierra Nevada Red Fox (\u3ci\u3eVulpes vulpes necator\u3c/i\u3e): A Conservation Assessment
One goal of the Sierra Nevada Forest Plan Amendment (SNFPA) 2001 and 2004 Records of Decision was to protect and recover native Sierra Nevada red fox (Vulpes vulpes necator) populations in the Sierra Nevada (USDA Forest Service 2001 p. 14). To accomplish this goal, the ROD commits the U.S. Department of Agriculture (USDA) Forest Service to completing a conservation assessment for the Sierra Nevada red fox in cooperation with other federal, state, and local agencies, as well as Tribal governments. This conservation assessment synthesizes the best available scientific information and thought concerning habitat relationships, population status and trends, historical and current distributions, and key threats potentially affecting the distribution, abundance and persistence of the Sierra Nevada red fox. Biologists and resource managers from the Forest Service, US Department of the Interior (USDI) National Park Service, USDI Fish and Wildlife Service, US Geological Survey, University of California, and California Department of Fish and Game, along with private research scientists, worked cooperatively to develop this assessment. This conservation assessment provides a scientifically sound, comprehensive assessment of the status of the Sierra Nevada red fox population and its habitat. It identifies and evaluates key threats affecting viability and describes management considerations that could form the basis of a strategy to conserve and recover populations throughout the range of this species
Niche Variation in Endemic Lilium pomponium on a Wide Altitudinal Gradient in the Maritime Alps
The relationship between altitudinal and ecological gradients has long been a dominant theme in plant ecology; moreover, how species respond to climate change has renewed this interest. Mediterranean mountains are often hotspots of endemism, and some endemic species have local distributions that span different climatic belts; hence, local variations in topography and fine-scaled niche conditions may play crucial roles in their persistence along such gradients. Studies of the fine-scaled niche are, however, very rare; most studies involve broad-scale variations in climatic parameters. The Turban lily, Lilium pomponium L. is endemic to the Maritime and Ligurian Alps, where it occurs across a wide altitudinal gradient. Previous work has shown no link between climatic marginality and geographic range limits on morphological traits and genetic variability; however, possible variations of local topographic and ecological parameters have not yet been examined. The objective of this paper is to characterise local ecological niche conditions of L. pomponium populations in the different bioclimatic zones it occupies along the altitudinal gradient. The species occurs in four main types of microecological niches. One of these niche types, with a high mineral cover, is the most abundantâtype 2: it was detected in 39% of sampled quadrats and occurs across the whole bioclimatic gradient. Other niche types are more limited to subsections of the gradient: type 3 (in 19% of sampled quadrats) is restricted to high-altitude sites (>1070 m.a.s.l.) and is characterised by high vegetation and litter cover; type 4 (26%) corresponds to more forested habitats on substrates with low water retention capacities, in more inland zones close to the centre of L. pomponium distribution and across a range of altitudes; and type 1 (16% of quadrat) only occurs in the Mediterranean part of the gradient, close to distribution limits in pockets of soil among large blocks of rocks, mainly found at mid-altitudes. Despite heterogeneity in the spatial locations of niche types, there is no correspondence between ecological gradients and the distribution limits of this species. Knowledge of the fine-scaled ecological conditions that determine niche types is thus essential for conservation management of the habitats of this species and for the exploration of its possible response to ongoing climate change
Earthquakes in California in 1893
The following paper is a continuation of similar records furnished by officers of the Lick Observatory, and completes the list up to the .end of 1893. It records all the shocks observed or felt on Mount Hamilton, and all those reported to the Lick Observatory by letter, as .well as newspaper reports of such earthquakes as occurred in the State during that year. It also includes a number of shocks in various localities on the Pacific coast, which it was thought might not have been recorded in other reports. No systematic examination of newspapers has been made, however, and some reports of earthquakes may have escaped notice
Ensuring Economic Viability and Sustainability of Coffee Production
Coffee, the worldâs favorite beverage, provides livelihoods for at least 60 million people across dozens of countries. Yet this beloved drink is experiencing a sustainability crisis. A sustained decline in world coffee prices has squeezed coffee producers, and thrown a tremendous number of producers below the global extreme poverty line. This report presents our research into sustainability within the coffee sector, including the results of our analytical and empirical modeling, and provides several recommendations
Lesions of the ventral hippocampus attenuate the acquisition but not expression of signâtracking behavior in rats
Individual variation in the attribution of motivational salience to rewardârelated cues is believed to underlie addiction vulnerability. Pavlovian conditioned approach measures individual variation in motivational salience by identifying rats that are attracted to and motivated by reward cues (signâtrackers) or motivationally fixed on the reward itself (goalâtrackers). Previously, it has been demonstrated that signâtrackers are more vulnerable to addictionâlike behavior. Moreover, signâtrackers release more dopamine in the nucleus accumbens than goalâtrackers in response to rewardârelated cues, and signâ but not goalâtracking behavior is dopamineâdependent. In the present study, we investigated whether the ventral hippocampus, a potent driver of dopaminergic activity in the nucleus accumbens, modulates the acquisition and expression of Pavlovian conditioned approach behavior. In Experiment 1, lesions of the ventral, but not dorsal or total hippocampus, decreased signâtracking behavior. In Experiment 2, lesions of the ventral hippocampus did not affect the expression of signâ or goalâtracking behaviors nor conditioned reinforcement. In addition, temporary inactivation of the ventral subiculum, the main output pathway of the ventral hippocampus, did not affect the expression of signâ or goalâtracking behaviors. Highâpressure liquid chromatography of nucleus accumbens tissue punches revealed that ventral hippocampal lesions decreased levels of homovanillic acid and the homovanillic acid/dopamine ratio (a marker of dopamine release and metabolism) in only signâtrackers, and decreased accumbal norepinephrine levels in both signâ and goalâtrackers. These results suggest that the ventral hippocampus is important for the acquisition but not expression of signâtracking behavior, possibly as a result of altered dopamine and norepinephrine in the nucleus accumbens. © 2016 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134415/1/hipo22619.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134415/2/hipo22619_am.pd
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