| Title: | Community responses of arthropods to a range of traditional and manipulated grazing in shortgrass steppe |
| Author(s): | Newbold TA; Stapp P; Levensailor KE; Derner JD; Lauenroth WK; |
| Address: | "Shortgrass Steppe LTER, Colorado State University, Fort Collins, CO 80523, USA" |
| ISSN/ISBN: | 1938-2936 (Electronic) 0046-225X (Linking) |
| Abstract: | "Responses of plants to grazing are better understood, and more predictable, than those of consumers in North American grasslands. In 2003, we began a large-scale, replicated experiment that examined the effects of grazing on three important arthropod groups-beetles, spiders, and grasshoppers-in shortgrass steppe of north-central Colorado. We investigated whether modifications of the intensity and seasonality of livestock grazing alter the structure and diversity of macroarthropod communities compared with traditional grazing practices. Treatments represented a gradient of grazing intensity by cattle and native herbivores: long-term grazing exclosures; moderate summer grazing (the traditional regime); intensive spring grazing; intensive summer grazing; and moderately summer-grazed pastures also inhabited by black-tailed prairie dogs (Cynomys ludovicianus Ord). Beetles and spiders were the most common groups captured, comprising 60% and 21%, respectively, of 4,378 total pitfall captures. Grasshopper counts were generally low, with 3,799 individuals observed and densities <4 m(-2). Two years after treatments were applied, vegetation structure differed among grazing treatments, responding not only to long-term grazing conditions, but also to the short-term, more-intensive grazing manipulations. In response, arthropods were, in general, relatively insensitive to these grazing-induced structural changes. However, species-level analyses of one group (Tenebrionidae) revealed both positive and negative effects of grazing treatments on beetle richness and activity-density. Importantly, these responses to grazing were more pronounced in a year when spring-summer rainfall was low, suggesting that both grazing and precipitation-which together may create the greatest heterogeneity in vegetation structure-are drivers of consumer responses in this system" |
| Keywords: | Animal Husbandry Animals Arthropods/*physiology *Biota Cattle/physiology Coleoptera/physiology Colorado Feeding Behavior Food Chain Grasshoppers/physiology *Grassland Sciuridae/physiology Seasons Spiders/physiology; |
| Notes: | "MedlineNewbold, T A Scott Stapp, Paul Levensailor, Katherine E Derner, Justin D Lauenroth, William K eng Research Support, Non-U.S. Gov't England 2014/05/02 Environ Entomol. 2014 Jun; 43(3):556-68. doi: 10.1603/EN12333. Epub 2014 Apr 28" |
