Impacts of Land Use on the Habitat and Macroinvertebrate Assemblage of the Tributaries of the Lower Brazos River

Impacts of Land Use on the Habitat and Macroinvertebrate Assemblage of the Tributaries of the Lower Brazos River
Author: Frances Patricia Lash
Publisher:
Total Pages: 136
Release: 2011
Genre: Aquatic invertebrates
ISBN:

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Ecological research on stream and river ecosystems aims to gain an understanding of the dynamic and complex impacts of environmental factors on biotic communities within riverine landscape (riverscape). Human activities significantly impact both terrestrial and aquatic ecosystems. Local environmental factors are known to influence the structure and function of stream ecosystems and biodiversity. The patterns of benthic macroinvertebrate distribution are related to the natural and human influenced variation of environmental factors. Ecologists assess stream physical and biological conditions in response to human land use activities using ecological indicators. This study is an assessment of the ecological condition of the Lower Brazos River Watershed. Macroinvertebrate assemblage structure was compared from 33 sites within the 6 subbasins differing in land use type and degree. Land use within the subbasins was measured using data from the National Land Use Database. Benthic macroinvertebrate samples were collected and a variety of physiochemical variables were measured. Multivariate analysis grouped the subbasins using habitat variables and macroinvertebrate assemblages. Decreasing habitat heterogeneity resulted in a decline of diversity and richness of organisms. Differences in the richness and diversity of the macroinvertebrate assemblages are attributed to habitat structure and land use. This study highlights the importance of considering both local habitat and landscape parameters of watersheds in stream biological assessments to understand the response of benthic communities to disturbances.

Unruly Waters

Unruly Waters
Author: Kenna Lang Archer
Publisher: UNM Press
Total Pages: 290
Release: 2015-05-01
Genre: History
ISBN: 0826355889

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Running more than 1,200 miles from headwaters in eastern New Mexico through the middle of Texas to the Gulf of Mexico, the Brazos River has frustrated developers for nearly two centuries. This environmental history of the Brazos traces the techniques that engineers and politicians have repeatedly used to try to manage its flow. The vast majority of projects proposed or constructed in this watershed were failures, undone by the geology of the river as much as the cost of improvement. When developers erected locks, the river changed course. When they built large-scale dams, floodwaters overflowed the concrete rims. When they constructed levees, the soils collapsed. Yet lawmakers and laypeople, boosters and engineers continued to work toward improving the river and harnessing it for various uses. Through the plight of the Brazos River Archer illuminates the broader commentary on the efforts to tame this nation’s rivers as well as its historical perspectives on development and technology. The struggle to overcome nature, Archer notes, reflects a quintessentially American faith in technology.