Salt cedar negatively affects biodiversity of aquatic Macroinvertebrates
Tóm tắt
Salt cedar (Tamarix ramossisima), an invasive species, has become a dominant shrub along many streams of the southwestern United States, where it has replaced many native species such as Fremont cottonwood (Populus fremontii). We examined whether the successful invasion of this exotic shrub alters stream leaf litter decomposition rates and affects the aquatic macroinvertebrates that are dependent on leaf litter as a food source. With an in-stream leaf pack experiment, we found that faster decomposition of salt cedar litter was associated with a two-fold decrease in macroinvertebrate richness and a four-fold decrease in overall macroinvertebrate abundance, relative to native Fremont cottonwood. Macroinvertebrate communities were also significantly different on the two food sources through time. These studies demonstrate that invasion by salt cedar affects leaf litter quality, which in turn affects stream macroinvertebrates. Such impacts on the primary consumers and food web structure could affect higher trophic levels.
Tài liệu tham khảo
Batzer, D. P., C. R. Pusateri, and R. Vetter. 2000. Impacts of fish predation on marsh invertebrates: direct and indirect effects. Wetlands 20:307–312.
Boulton, A. J. and P. I. Boon. 1991. A review of methodology used to measure leaf litter decomposition in lotic environments: time to turn over an old leaf? Australian Journal of Marine Freshwater Research 42:1–43.
Boulton, A. J., M. R. Scarsbrook, J. M. Quinn, and G. P. Burrell. 1997. Land use effects on the hyporheic ecology of five small streams near Hamilton, New Zealand. New Zealand Journal of Marine Freshwater Research 31:609–622.
Brown, D. E. 1982. Biotic Communities of the American Southwest-United States and Mexico. Desert Plants 4(1–4). University of Arizona Press, Tucson, AZ, USA.
Corkum, L. D. 1991. Spatial patterns of macroinvertebrate distributions along rivers in eastern deciduous forest and grassland biomes. Journal of the North American Benthological Society 10: 358–371.
Dobson, M. 1994. Microhabitat as a determinant of diversity: stream invertebrates colonizing leaf packs. Freshwater Biology 32:565–572.
Driebe, E. and T. G. Whitham. 2000. Cottonwood hybridization affects tannin and nitrogen content of leaf litter and alters decomposition. Oecologia 123:99–107.
Dungey, H. S., B. M. Potts, T. G. Whitham, and H.-F. Li. 2000. Plant genetics affects arthropod community richness and composition: evidence from a synthetic eucalypt hybrid population. Evolution 54:1938–1946.
El-Beheiry, M. A. H. and H. F. El-Kady. 1998. Nutritive value of two Tamarix species in Egypt. Journal of Arid Environments 38: 529–539.
Everitt, B. L. 1998. Chronology of the spread of Tamarisk in the central Rio Grande. Wetlands 18:658–668.
Gillis, A. M. 1992. Keeping aliens out of paradise: Government agencies and environmental groups are looking for ways to keep nonnative animal and plant pests out of Hawaii. Bioscience 42: 482–485.
Gregory, S. V., F. J. Swanson, W. A. McKee, and K. W. Cummins. 1991. An ecosystem perspective of riparian zones: focus on links between land and water. Bioscience 41:540–551.
Gladwin, D. N. and J. E. Roelle. 1998. Survival of plains cotton-wood (Populus deltoides subsp. Monilifera) and saltcedar (Tamarix ramosissima) seedlings in response to flooding. Wetlands 18:669–674.
Merritt, R. W. and K. W. Cummins. 1984. An Introduction to the Aquatic Insects of North America. Second Edition. Kendall/Hunt Publishing, Dubuque, Iowa, USA.
Minchin, P. R. 1987a. An evaluation of the relative robustness of techniques for ecological ordination. Vegetatio 69:89–107.
Minchin, P. R. 1987b. Simulation of multidimensional community patterns: towards a comprehensive model. Vegetatio 71:145–156.
Naiman, R. J., H. Decamps, and M. Pollock. 1993. The role of riparian corridors in maintaining regional biodiversity. Ecological Applications 3:209–212.
Naeem, S., L. J. Thompson, S. P. Lawler, J. H. Lawton, and R. M. Woodfin. 1994. Declining biodiversity can alter the performance of ecosystems. Nature 368:734–736.
Noss, R. F., E. T. LaRoe III, and J. M. Scott. 1995. Endangered ecosystems of the United States: A preliminary assessment of loss and degradation. U.S. Department of the Interior, National Biological Service, Washington, DC, USA Biological Report 28.
Oksanen, J. and P. R. Minchin. 1997. Instability of ordination results under changes in input order: explanations and remedies. Journal of Vegetation Science 8:447–454.
Power, M. E. 1990. Effects of fish in river food webs. Science 250: 811–14.
Schade, J. D. and S. G. Fisher. 1997. Leaf litter in a Sonoran Desert stream ecosystem. Journal of North American Benthological Society 16:612–626.
Schulze, D. J. and K. F. Walker. 1997. Riparian eucalypts and willows and their significance for aquatic invertebrates in the River Murray, South Australia. Regulated Rivers 13:557–577.
Stein, B. A. and S. R. Flack. 1997. Conservation priorities: the state of U.S. plants and animals. Environment 39:6–11.
Stevens, L. 1985. Invertebrate herbivore community dynamics on Tamarix chinensis loueiro and Salix exigua Nuttall in the Grand Canyon, Arizona. Masters Thesis. Northern Arizona University, Flagstaff, AZ, USA.
Vannote, R. L., W. M. Minshall, K. W. Cummins, J. R. Sedell, and C. E. Cushing. 1980. The River Continuum Concept. Canadian Journal of Fisheries and Aquatic Sciences 37:130–137.
Wallace, J. B., S. L. Eggert, J. L. Meyer, and J. R. Webster. 1997. Multiple trophic levels of a forest stream linked to terrestrial litter inputs. Science 277:102–104.
Weller, M. W. 1981. Freshwater Marshes. University of Minnesota Press, Minneapolis, MN, USA.