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51.
Earthworms have an important role in ‘bioturbation’—the mixing of soil due to biological processes. Quantification of earthworm bioturbation relies on estimating earthworm egestion rates which in turn depend on two parameters: the gut content of the worms and the gut transit time (GTT). Gut content can be determined relatively easily, but determining GTT is problematic. The present study aimed at estimating daily soil egestion rates of Aporrectodea caliginosa and Lumbricus terrestris, refining the most common approach for estimating GTT by using fungal spores as natural markers in ingested soil. This approach avoids the use of artificial markers that may adversely affect the earthworms. Gut transit time was estimated by tracking the passage of marked soil through the gut by the appearance of the spores in the egested faeces. Gut transit time was estimated to be 9.6?±?0.3 h for A. caliginosa and 11.6?±?0.5 h for L. terrestris. Gut content averaged 465?±?40(± standard error (SE))?mg dw g?1 dw worm for A. caliginosa and 265?±?80 mg dw g?1 dw worm for L. terrestris. From these values, daily egestion rates of 1.16 and 0.66 g dw faeces g?1 dw worm d?1 were calculated for A. caliginosa and L. terrestris, respectively. Both values compare well to literature values for each species. The presented method for GTT estimation is inexpensive, rapid and easy to evaluate, with spores being a good alternative to existing markers. 相似文献
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Validation of an enzyme‐linked immunosorbent assay (ELISA) for the measurement of canine S100A12 
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下载免费PDF全文 55.
Daniel A. Chapman Tyler O. Gagne Kimberly L. Ovitz Lucas P. Griffin Andy J. Danylchuk Ezra M. Markowitz 《Human Dimensions of Wildlife》2018,23(4):391-398
Catch-and-release (C&R) angling is a powerful tool for reducing impacts on recreationally targeted fishes. Although C&R can be mandated in fisheries through regulation, voluntary adoption and informal management are often critical due to minimal enforcement opportunities. Anglers themselves may play a role in increasing C&R adoption through interpersonal sanctioning (i.e., self-policing). To date, little research has examined factors that predict the willingness of anglers to sanction others’ behavior. We present results from surveys (n = 49) with anglers in Argentina to explore their motivations to sanction other anglers within their stakeholder community. Anglers with the strongest intentions to sanction were younger and more open to adopting best practices, identified fishing as important to their lifestyle, and expressed high environmental concern relative to other anglers. Our findings highlight the role that recreational anglers can play in promoting best practices via interpersonal sanctioning and identify barriers that inhibit this type of action. 相似文献
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Studies of effects of fertilizer treatment on ectomycorrhizal fungal community structure have predominantly been based on large, single additions of nitrogen. Studies involving chronic additions of nutrients in combination with irrigation are much less common. We used morphotyping to study effects of balanced additions of a nutrient solution on ectomycorrhizal fungal community structure in a 36-year-old stand of Picea abies (L.) Karst. Despite high variability among individual samples, principal components analysis revealed a clear shift in community structure in response to fertilization. Irrigated plots receiving only water did not differ significantly from untreated control plots. Mycorrhizal root tips colonized by Cenococcum geophilum Fr. were significantly more common in fertilized plots than in control plots. Possible responses by other ectomycorrhizal species were masked by high variability. Over sixty morphotypes were distinguished, but there was no measurable effect of either fertilizer or irrigation treatment on morphotype richness or total number of root tips. 相似文献
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