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Author: Kate Roberts Publisher: ISBN: Category : Invertebrate communities Languages : en Pages : 0
Book Description
Natural stresses such as drought can cause changes in macroinvertebrate community composition over time. This study examines the relationship between low flows, macroinvertebrate habitat and the macroinvertbrate community. The sensitivity of AUSRIVAS biological monitoring methods to impacts associated with low flows are also examined. A flow threshold was used to define low flows and to test for changes in macroinvertebrate habitat and macroinvertebrate communities. Assessments of the biological condition of the macroinvertebrate community were performed using AUSRIVAS predictive models. Low flows reduced the available habitat for macroinvertebrates, thus altering resources for macroinvertebrates. However, macroinvertebrate abundance and community composition showed no significant response to the effects of low. AUSRIVAS assessments detected few reductions in biological condition of macroinvertebrate under low flow conditions. The threshold value used to define drought was useful for determining habitat change, but was appropriate for determinig levels at which changes to the macroinvertebrate community occur. Alternative methods such as a combination of low flow thresholds, low flow duration and channel characteristics may enable observations of biological impacts associated with low flow conditions.
Author: Kate Roberts Publisher: ISBN: Category : Invertebrate communities Languages : en Pages : 0
Book Description
Natural stresses such as drought can cause changes in macroinvertebrate community composition over time. This study examines the relationship between low flows, macroinvertebrate habitat and the macroinvertbrate community. The sensitivity of AUSRIVAS biological monitoring methods to impacts associated with low flows are also examined. A flow threshold was used to define low flows and to test for changes in macroinvertebrate habitat and macroinvertebrate communities. Assessments of the biological condition of the macroinvertebrate community were performed using AUSRIVAS predictive models. Low flows reduced the available habitat for macroinvertebrates, thus altering resources for macroinvertebrates. However, macroinvertebrate abundance and community composition showed no significant response to the effects of low. AUSRIVAS assessments detected few reductions in biological condition of macroinvertebrate under low flow conditions. The threshold value used to define drought was useful for determining habitat change, but was appropriate for determinig levels at which changes to the macroinvertebrate community occur. Alternative methods such as a combination of low flow thresholds, low flow duration and channel characteristics may enable observations of biological impacts associated with low flow conditions.
Author: Elena Blair Publisher: ISBN: Category : Droughts Languages : en Pages : 47
Book Description
Although most streams in California are intermittent, bioassessment protocols are designed for perennial streams, with sampling periods anytime between April and June. Sampling intermittent streams during this period may not provide an accurate assessment of stream health, because of the stream community dynamics related to the predictable drying of intermittent streams in Mediterranean climates. Furthermore, climate change may cause perennial streams to become intermittent and intermittent streams to cease flow entirely. The objectives of this study were to assess the recolonization process and community dynamics within and among three intermittent streams each with a different hydrologic regime (dry, isolated pools, and low flow in the summer/fall months) and to assess whether the current bioassessment protocol sampling period appropriately accounts for differences in community composition recovery of intermittent streams. Macroinvertebrates and environmental information were collected at three intermittent streams from August 2013 to July 2014 near Sunol, CA. Sampling was conducted at frequent intervals (1, 8, 15, and 22 days) once stream flow resumed after the dry season; after 22 days, samples were collected every three weeks until the streams dried. All streams exhibited rapid recolonization (especially San Antonio Creek, which only flowed for five weeks) once flow resumed, suggesting taxa were well adapted to the Mediterranean climate and may have resistant/resilient life history traits to survive drying in the summer months. Taxa richness was highest in isolated pool habitats (due to an increase in x predatory and air breathing taxa), contradicting most findings that increased connectivity is associated with higher taxa richness. Non Metric Multidimensional Scaling was used to assess community composition within and among the three streams. Communities became more similar during months of continuous flow (February, March, and early April), suggesting that an earlier sampling window than currently used would be useful for bioassessment. In conclusion, there is a need for more studies regarding macroinvertebrate community dynamics in relation to standard bioassessment sampling protocols and how the effects of floods, flow permanence, and drought influence community dynamics in Mediterranean climate intermittent streams.
Author: Nancy D. Gordon Publisher: John Wiley & Sons ISBN: 1118688171 Category : Technology & Engineering Languages : en Pages : 637
Book Description
Since the publication of the first edition (1994) there have been rapid developments in the application of hydrology, geomorphology and ecology to stream management. In particular, growth has occurred in the areas of stream rehabilitation and the evaluation of environmental flow needs. The concept of stream health has been adopted as a way of assessing stream resources and setting management goals. Stream Hydrology: An Introduction for Ecologists Second Edition documents recent research and practice in these areas. Chapters provide information on sampling, field techniques, stream analysis, the hydrodynamics of moving water, channel form, sediment transport and commonly used statistical methods such as flow duration and flood frequency analysis. Methods are presented from engineering hydrology, fluvial geomorphology and hydraulics with examples of their biological implications. This book demonstrates how these fields are linked and utilised in modern, scientific river management. * Emphasis on applications, from collecting and analysing field measurements to using data and tools in stream management. * Updated to include new sections on environmental flows, rehabilitation, measuring stream health and stream classification. * Critical reviews of the successes and failures of implementation. * Revised and updated windows-based AQUAPAK software. This book is essential reading for 2nd/3rd year undergraduates and postgraduates of hydrology, stream ecology and fisheries science in Departments of Physical Geography, Biology, Environmental Science, Landscape Ecology, Environmental Engineering and Limnology. It would be valuable reading for professionals working in stream ecology, fisheries science and habitat management, environmental consultants and engineers.
Author: Thomas William Hallamore Aspin Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Climate change is subjecting many ecosystems to novel environmental conditions, including unprecedented extremes of drought that may push communities beyond critical ecological thresholds. Stream ecosystems may be particularly prone to catastrophic responses, due to a dependence on flowing water and continued exposure to other major threats to their ecological integrity. However, a lack of gradient-based approaches that explore beyond the limits of current disturbance regimes constrains our ability to predict the impacts of future droughts. This study used artificial channels (mesocosms) as perennial headwater stream analogues to simulate a broad gradient of drought intensity, ranging from flowing controls through fragmented pools to dewatered streambeds. Drought intensification pushed macroinvertebrate communities over structural and functional thresholds, and eroded complex food webs from the top down and the bottom up. Moreover, important exceptions to some established 'rules' in disturbance ecology emerged, with population collapses not biased to larger body sizes or higher trophic levels, and community responses not buffered by high functional redundancy. Benthic algae, macroinvertebrates and fish were all sensitive to relatively low intensity drought, suggesting that pool fragmentation, and not streambed drying, may be the most crucial stage of habitat loss for many running water ecosystems.
Author: P. Sam Lake Publisher: John Wiley & Sons ISBN: 1444341790 Category : Science Languages : en Pages : 458
Book Description
Droughts are a major hazard to both natural and human-dominated environments and those, especially of long duration and high intensity, can be highly damaging and leave long-lasting effects. This book describes the climatic conditions that give rise to droughts, and their various forms and chief attributes. Past droughts are described including those that had severe impacts on human societies. As a disturbance, droughts can be thought of as “ramps” in that they usually build slowly and take time to become evident. As precipitation is reduced, flows from catchments into aquatic systems decline. As water declines in water bodies, ecological processes are changed and the biota can be drastically reduced, though species and populations may survive by using refuges. Recovery from drought varies in both rates and in degrees of completeness and may be a function of both refuge availability and connectivity. For the first time, this book reviews the available rather scattered literature on the impacts of drought on the flora, fauna and ecological processes of aquatic ecosystems ranging from small ponds to lakes and from streams to estuaries. The effects of drought on the biota of standing waters and flowing waters and of temporary waters and perennial systems are described and compared. In addition, the ways in which human activity can exacerbate droughts are outlined. In many parts of the world especially in the mid latitudes, global warming may result in increases in the duration and intensity of droughts. Drought and Aquatic Ecosystems is essential reading for freshwater ecologists, water resource managers and advanced students.
Author: Thibault Datry Publisher: Academic Press ISBN: 0128039043 Category : Science Languages : en Pages : 624
Book Description
Intermittent Rivers and Ephemeral Streams: Ecology and Management takes an internationally broad approach, seeking to compare and contrast findings across multiple continents, climates, flow regimes, and land uses to provide a complete and integrated perspective on the ecology of these ecosystems. Coupled with this, users will find a discussion of management approaches applicable in different regions that are illustrated with relevant case studies. In a readable and technically accurate style, the book utilizes logically framed chapters authored by experts in the field, allowing managers and policymakers to readily grasp ecological concepts and their application to specific situations. - Provides up-to-date reviews of research findings and management strategies using international examples - Explores themes and parallels across diverse sub-disciplines in ecology and water resource management utilizing a multidisciplinary and integrative approach - Reveals the relevance of this scientific understanding to managers and policymakers
Author: Anthea R. Florance Publisher: ISBN: Category : Cotter River Region (A.C.T.) Languages : en Pages : 98
Book Description
Abstract: "This study examines a long-term data set, collected by the Institute for Applied Ecology (IAE) Freshwater Ecology Laboratory (University of Canberra) between the years of 1994-2013, which takes into account these disturbance events. The objectives of this study were: 1.) to determine how stream macroinvertebrate communities responded to drought, fire and flood disturbance within the LCC [Lower Cotter Catchment] and, 2.) to determine whether former forestry land-use affected how stream macroinvertebrate communities responded to drought, fire and flood disturbance within the LCC."
Author: John Gooderham Publisher: CSIRO PUBLISHING ISBN: 9780643066687 Category : Nature Languages : en Pages : 246
Book Description
Freshwater invertebrates identification guide for both professionals and non-professionals. Contains a key to all the macroinvertebrate groups and photographs of live specimens.
Author: G.E. Petts Publisher: Springer Science & Business Media ISBN: 9400914911 Category : Science Languages : en Pages : 792
Book Description
Fluvial Hydrosystems provides a unified approach to the study of running waters and aims to provide a scientific basis for sustainable management of rivers. It differs from traditional texts in viewing rivers as structured, four-dimensional systems and integrating ecological and geomorphological approaches to provide a holistic perspective on river dynamics. Advanced students of geomorphology, ecology, environmental science, land use and civil engineering will all benefit from this wide-ranging and stimulating textbook.
Author: Kate Roberts
Author: Kate Roberts
Author: Elena Blair
Author: Nancy D. Gordon
Author: Jan Lepš
Author: Thomas William Hallamore Aspin
Author: P. Sam Lake
Author: Thibault Datry
Author: Anthea R. Florance
Author: John Gooderham
Author: G.E. Petts