38 research outputs found

    Long‐term monitoring and experimental manipulation of a Chihuahuan desert ecosystem near Portal, Arizona (1977–2013)

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    Desert ecosystems have long served as model systems in the study of ecological concepts (e.g., competition, resource pulses, top‐down/bottom‐up dynamics). However, the inherent variability of resource availability in deserts, and hence consumer dynamics, can also make them challenging ecosystems to understand. Study of a Chihuahuan desert ecosystem near Portal, Arizona began in 1977. At this site, 24 experimental plots were established and divided among controls and experimental manipulations. Experimental manipulations over the years include removal of all or some rodent species, all or some ants, seed additions, and various alterations of the annual plant community. This dataset includes data previously available through an older data publication and adds 11 years of data. It also includes additional ant and weather data not previously available. These data have been used in a variety of publications documenting the effects of the experimental manipulations as well as the response of populations and communities to long‐term changes in climate and habitat. Sampling is ongoing and additional data will be published in the future.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/1/ecy1360.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146431/2/ecy1360_am.pd

    Soil foraging animals alter the composition and co-occurrence of microbial communities in a desert shrubland

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    Animals that modify their physical environment by foraging in the soil can have dramatic effects on ecosystem functions and processes. We compared bacterial and fungal communities in the foraging pits created by bilbies and burrowing bettongs with undisturbed surface soils dominated by biocrusts. Bacterial communities were characterized by Actinobacteria and Alphaproteobacteria, and fungal communities by Lecanoromycetes and Archaeosporomycetes. The composition of bacterial or fungal communities was not observed to vary between loamy or sandy soils. There were no differences in richness of either bacterial or fungal operational taxonomic units (OTUs) in the soil of young or old foraging pits, or undisturbed soils. Although the bacterial assemblage did not vary among the three microsites, the composition of fungi in undisturbed soils was significantly different from that in old or young foraging pits. Network analysis indicated that a greater number of correlations between bacterial OTUs occurred in undisturbed soils and old pits, whereas a greater number of correlations between fungal OTUs occurred in undisturbed soils. Our study suggests that digging by soil-disturbing animals is likely to create successional shifts in soil microbial and fungal communities, leading to functional shifts associated with the decomposition of organic matter and the fixation of nitrogen. Given the primacy of organic matter decomposition in arid and semi-arid environments, the loss of native soil-foraging animals is likely to impair the ability of these systems to maintain key ecosystem processes such as the mineralization of nitrogen and the breakdown of organic matter, and to recover from disturbance

    Evidence of Latitudinal Migration in Tri-colored Bats, Perimyotis subflavus

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    Background: Annual movements of tri-colored bats (Perimyotis subflavus) are poorly understood. While this species has been considered a regional migrant, some evidence suggests that it may undertake annual latitudinal migrations, similar to other long distance North American migratory bat species. Methodology/Principal Findings: We investigated migration in P. subflavus by conducting stable hydrogen isotope analyses of 184 museum specimen fur samples and comparing these results (dDfur) to published interpolated dD values of collection site growing season precipitation (dDprecip). Results suggest that the male molt period occurred between June 23 and October 16 and 33 % of males collected during the presumed non-molt period were south of their location of fur growth. For the same time period, 16 % of females were south of their location of fur growth and in general, had not travelled as far as migratory males. There were strong correlations between dDfur from the presumed molt period and both growing season dD precip (males – r 2 = 0.86; p,0.01; females – r 2 = 0.75; p,0.01), and latitude of collection (males – r 2 = 0.85; p,0.01; females – r 2 = 0.73; p,0.01). Most migrants were collected at the northern (.40uN; males and females) and southern (,35uN; males only) extents of the species ’ range. Conclusions/Significance: These results indicate a different pattern of migration for this species than previously documented, suggesting that some P. subflavus engage in annual latitudinal migrations and that migratory tendency varie

    Carrion Availability in Space and Time

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    Introduction Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. “Carrion Exchange at the Terrestrial-Aquatic Interface”). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; Moleón et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter “Human-Mediated Carrion: Effects on Ecological Processes”. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (Donázar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar

    Range extension for DeKay’s Brownsnake (\u3ci\u3eStoreria dekayi\u3c/i\u3e) in south-central Nebraska

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    Dekay’s Brownsnake (Storeria dekayi) generally occurs in southeastern parts of the state, where the species was known from 16 counties. Herein, we update the distribution of S. dekayi in the state and briefly comment on habitat and abundance from observations in September and October 2018. We documented 7 new county records that extend its distribution in south-central Nebraska. We observed that S. dekayi does not only reside in mesic wooded habitats in Nebraska but also occupies open environments, including areas with upland grasslands and row-crop agriculture. Dekay’s Brownsnake currently is listed as a species of concern in Nebraska. Our limited data do not support that S. dekayi needs protection in Nebraska, as the species occurs over a much larger area of the state than previously known and was the most common species observed along roadways in autumn 2018

    Range extension for DeKay’s Brownsnake (\u3ci\u3eStoreria dekayi\u3c/i\u3e) in south-central Nebraska

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    Dekay’s Brownsnake (Storeria dekayi) generally occurs in southeastern parts of the state, where the species was known from 16 counties. Herein, we update the distribution of S. dekayi in the state and briefly comment on habitat and abundance from observations in September and October 2018. We documented 7 new county records that extend its distribution in south-central Nebraska. We observed that S. dekayi does not only reside in mesic wooded habitats in Nebraska but also occupies open environments, including areas with upland grasslands and row-crop agriculture. Dekay’s Brownsnake currently is listed as a species of concern in Nebraska. Our limited data do not support that S. dekayi needs protection in Nebraska, as the species occurs over a much larger area of the state than previously known and was the most common species observed along roadways in autumn 2018

    Habitat utilization of mammals in a man-made forest in the Sandhill region of Nebraska

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