2006
Howard, Jeanette K.; Cuffey, Kurt M.
Factors controlling the age structure of Margaritifera falcata in 2 northern California streams Journal Article
In: Journal of the North American Benthological Society, vol. 25, no. 3, pp. 677-690, 2006.
Abstract | Links | BibTeX | Tags: age structure, annual rings, California, discharge, freshwater mussels, Margaritifera falcata, mortality, recruitment
@article{Howard2006b,
title = {Factors controlling the age structure of Margaritifera falcata in 2 northern California streams},
author = {Jeanette K. Howard and Kurt M. Cuffey},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Howard_2006_Bentho.pdf},
doi = {10.1899/0887-3593(2006)25[677:FCTASO]2.0.CO;2},
year = {2006},
date = {2006-01-01},
journal = {Journal of the North American Benthological Society},
volume = {25},
number = {3},
pages = {677-690},
abstract = {Freshwater mussels are long-lived and relatively stationary organisms that form annual rings, so they provide excellent opportunities for studying how population properties such as age structure relate to environmental influences on recruitment and mortality. We investigated population dynamics of the freshwater pearl mussel, Margaritifera falcata, in 2 northern California Coast Range rivers, the South Fork Eel and the Navarro. We used field observations and inverse theoretical modeling to assess age structures and identify factors that control population demographics. Distinctly different mortality rates for young (<20 y) and old (≥20 y) mussels were observed in the South Fork Eel, and recruitment and mortality both were related to river discharge regimes. Margaritifera falcata recruited more successfully during low-discharge than during high-discharge years, and a 2-fold increase in discharge caused a 60% decline in recruitment success. Active annual recruitment (˜1100–1800 ind./y) was observed in the South Fork Eel, whereas recruitment has been low or nonexistent during the past 30 y in the Navarro. This difference probably is a consequence of the influence of 2 non-mutually exclusive factors: landuse history and host-fish abundance. The Navarro watershed has extensive timber harvesting and orchard/vineyard agriculture and has had severe declines in fish populations, whereas large sections of the South Fork Eel pass through protected land and the river has retained its historical fish populations. Investigation of the factors that shape local M. falcata population age structures yielded insights into the influence of environmental variables and history on mortality and recruitment that will aid conservation of this endangered family.},
keywords = {age structure, annual rings, California, discharge, freshwater mussels, Margaritifera falcata, mortality, recruitment},
pubstate = {published},
tppubtype = {article}
}
Freshwater mussels are long-lived and relatively stationary organisms that form annual rings, so they provide excellent opportunities for studying how population properties such as age structure relate to environmental influences on recruitment and mortality. We investigated population dynamics of the freshwater pearl mussel, Margaritifera falcata, in 2 northern California Coast Range rivers, the South Fork Eel and the Navarro. We used field observations and inverse theoretical modeling to assess age structures and identify factors that control population demographics. Distinctly different mortality rates for young (<20 y) and old (≥20 y) mussels were observed in the South Fork Eel, and recruitment and mortality both were related to river discharge regimes. Margaritifera falcata recruited more successfully during low-discharge than during high-discharge years, and a 2-fold increase in discharge caused a 60% decline in recruitment success. Active annual recruitment (˜1100–1800 ind./y) was observed in the South Fork Eel, whereas recruitment has been low or nonexistent during the past 30 y in the Navarro. This difference probably is a consequence of the influence of 2 non-mutually exclusive factors: landuse history and host-fish abundance. The Navarro watershed has extensive timber harvesting and orchard/vineyard agriculture and has had severe declines in fish populations, whereas large sections of the South Fork Eel pass through protected land and the river has retained its historical fish populations. Investigation of the factors that shape local M. falcata population age structures yielded insights into the influence of environmental variables and history on mortality and recruitment that will aid conservation of this endangered family.
1988
Power, Mary E.; Stout, R. Jean; Cushing, Colbert E.; Harper, Peter P.; Hauer, F. Richard; Matthews, William J.; Moyle, Peter B.; Statzner, Bernhard; Badgen, Irene R. Wais De
Biotic and abiotic controls in river and stream communities Journal Article
In: Journal of the North American Benthological Society, vol. 7, no. 4, pp. 456-479, 1988.
Abstract | Links | BibTeX | Tags: algae, COMMUNITIES, discharge, disturbance., fish, life histories, rivers, streams, zoobenthos
@article{Power1988,
title = {Biotic and abiotic controls in river and stream communities},
author = {Mary E. Power and R. Jean Stout and Colbert E. Cushing and Peter P. Harper and F. Richard Hauer and William J. Matthews and Peter B. Moyle and Bernhard Statzner and Irene R. Wais De Badgen},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_1988_BenthoSoc.pdf},
doi = {10.2307/1467301},
year = {1988},
date = {1988-12-00},
journal = {Journal of the North American Benthological Society},
volume = {7},
number = {4},
pages = {456-479},
abstract = {Lotic ecologists share a major goal of explaining the distribution and abundance of biota in the world's rivers and streams, and of predicting how this biota will respond to change in fluvial ecosystems. We discuss five areas of research that would contribute to our pursuit of this goal. For mechanistic understanding of lotic community dynamics, we need more information on:
1. Physical conditions impinging on lotic biota, measured on temporal and spatial scales relevant to the organisms.
2. Responses of lotic biota to discharge fluctuations, including the processes that mediate community recovery following resets caused by spates or droughts.
3. Movements of lotic organisms that mediate gene flow, resource tracking, and multilevel species interactions.
4. Life history patterns, with special emphasis on ontogenetic bottlenecks that determine the vulnerability of populations confronting environmental perturbation.
5. Consequences of species interactions for community- and ecosystem-level processes in rivers and streams.
Without attempting to be comprehensive in our review, we discuss limits and limitations of our knowledge in these areas. We also suggest types of data and technological development that would advance our understanding. While we appreciate the value and need for empirical and comparative information, we advocate search for key mechanisms underlying community interactions as the crucial step toward developing general predictions of responses to environmental change. These mechanisms are likely to be complex, and elucidation of interacting bilateral, or multilateral, biotic and abiotic controls will progress only with the continuing synthesis of community- and ecosystem-level approaches in lotic ecology.},
keywords = {algae, COMMUNITIES, discharge, disturbance., fish, life histories, rivers, streams, zoobenthos},
pubstate = {published},
tppubtype = {article}
}
Lotic ecologists share a major goal of explaining the distribution and abundance of biota in the world’s rivers and streams, and of predicting how this biota will respond to change in fluvial ecosystems. We discuss five areas of research that would contribute to our pursuit of this goal. For mechanistic understanding of lotic community dynamics, we need more information on:
1. Physical conditions impinging on lotic biota, measured on temporal and spatial scales relevant to the organisms.
2. Responses of lotic biota to discharge fluctuations, including the processes that mediate community recovery following resets caused by spates or droughts.
3. Movements of lotic organisms that mediate gene flow, resource tracking, and multilevel species interactions.
4. Life history patterns, with special emphasis on ontogenetic bottlenecks that determine the vulnerability of populations confronting environmental perturbation.
5. Consequences of species interactions for community- and ecosystem-level processes in rivers and streams.
Without attempting to be comprehensive in our review, we discuss limits and limitations of our knowledge in these areas. We also suggest types of data and technological development that would advance our understanding. While we appreciate the value and need for empirical and comparative information, we advocate search for key mechanisms underlying community interactions as the crucial step toward developing general predictions of responses to environmental change. These mechanisms are likely to be complex, and elucidation of interacting bilateral, or multilateral, biotic and abiotic controls will progress only with the continuing synthesis of community- and ecosystem-level approaches in lotic ecology.
1. Physical conditions impinging on lotic biota, measured on temporal and spatial scales relevant to the organisms.
2. Responses of lotic biota to discharge fluctuations, including the processes that mediate community recovery following resets caused by spates or droughts.
3. Movements of lotic organisms that mediate gene flow, resource tracking, and multilevel species interactions.
4. Life history patterns, with special emphasis on ontogenetic bottlenecks that determine the vulnerability of populations confronting environmental perturbation.
5. Consequences of species interactions for community- and ecosystem-level processes in rivers and streams.
Without attempting to be comprehensive in our review, we discuss limits and limitations of our knowledge in these areas. We also suggest types of data and technological development that would advance our understanding. While we appreciate the value and need for empirical and comparative information, we advocate search for key mechanisms underlying community interactions as the crucial step toward developing general predictions of responses to environmental change. These mechanisms are likely to be complex, and elucidation of interacting bilateral, or multilateral, biotic and abiotic controls will progress only with the continuing synthesis of community- and ecosystem-level approaches in lotic ecology.