
STANDING CROP AND COMMUNITY STRUCTURE OF
... "standing crop" during a period of time as (a) - abundance -of plankton, (b) volume -of plankton, (c) ash~free dry weight, and (d) chlorophyll content of the water. ...
... "standing crop" during a period of time as (a) - abundance -of plankton, (b) volume -of plankton, (c) ash~free dry weight, and (d) chlorophyll content of the water. ...
Drought and Aquatic Ecosystems
... pollution). It is also very scattered across different types of publications, is uneven in quality, and some of it is quite difficult to access (Lake et al., 2008). Following the international conference on the ‘Role of Drought in the Ecology of Aquatic Systems’ in Albury, Australia in 2001 (Humphri ...
... pollution). It is also very scattered across different types of publications, is uneven in quality, and some of it is quite difficult to access (Lake et al., 2008). Following the international conference on the ‘Role of Drought in the Ecology of Aquatic Systems’ in Albury, Australia in 2001 (Humphri ...
Research Information Needs
... information is not worth the expense, this RIN will not be pursued.) RIN 1.1.3 - How do top-down effects (grazing and predation) on primary producers affect food base productivity? RIN 1.1.4 - What are the habitat characteristics between GCD and the Paria River that most affect primary productivity? ...
... information is not worth the expense, this RIN will not be pursued.) RIN 1.1.3 - How do top-down effects (grazing and predation) on primary producers affect food base productivity? RIN 1.1.4 - What are the habitat characteristics between GCD and the Paria River that most affect primary productivity? ...
Coho Salmon (Oncorhynchus kisutch) Life History Patterns in the
... Figure 12. Water depth and velocity preferences of subyearling coho salmon found in rivers of Western Washington. From Beecher et al. (2002). Water velocities are measured at 0.6 depth (approximately equal to mean water column values). Note: 30.5 cm = 1 ft..... 21 Figure 13. Coastal coho foraging p ...
... Figure 12. Water depth and velocity preferences of subyearling coho salmon found in rivers of Western Washington. From Beecher et al. (2002). Water velocities are measured at 0.6 depth (approximately equal to mean water column values). Note: 30.5 cm = 1 ft..... 21 Figure 13. Coastal coho foraging p ...
The importance of predation, cannibalism and resources for
... affects substrate composition and oxygen content of the stream (Sandin 2003). In lakes the depth and circulation may be of more importance than in streams. High levels of nitrogen can in some cases promote anoxia at deep water as oxygen is not circulated all way down in lakes all year round, which m ...
... affects substrate composition and oxygen content of the stream (Sandin 2003). In lakes the depth and circulation may be of more importance than in streams. High levels of nitrogen can in some cases promote anoxia at deep water as oxygen is not circulated all way down in lakes all year round, which m ...
Relative abundance and habitat association of three crayfish
... We documented the abundance and habitat association of the native virile crayfish [Orconectes virilis (Hagen, 1870)] and two invasive species, the rusty crayfish [O. rusticus (Girard, 1852)] and the papershell crayfish [O. immunis (Hagen, 1870)] in a 38 km2 area in the Lake of the Woods (LOW; Canada ...
... We documented the abundance and habitat association of the native virile crayfish [Orconectes virilis (Hagen, 1870)] and two invasive species, the rusty crayfish [O. rusticus (Girard, 1852)] and the papershell crayfish [O. immunis (Hagen, 1870)] in a 38 km2 area in the Lake of the Woods (LOW; Canada ...
Critical Habitat - Center for Biological Diversity
... 2009a, pp. 2, 5–8). (We use the term ‘‘translocate’’ to describe stocking fish into an area where suitable habitat exists, but for which there are no documented collections.) Both Hot Springs and Redfield canyons are tributaries to the San Pedro River. Spikedace were also translocated into Fossil Cr ...
... 2009a, pp. 2, 5–8). (We use the term ‘‘translocate’’ to describe stocking fish into an area where suitable habitat exists, but for which there are no documented collections.) Both Hot Springs and Redfield canyons are tributaries to the San Pedro River. Spikedace were also translocated into Fossil Cr ...
Estuarine Nutrient Cycling - The Influence of
... 1995; Schramm 1996). These inherent differences may influence the way that different plant types respond to environmental changes (for example eutrophication), but we also expect that they affect the fate of organic matter produced during photosynthesis and, thus, modify major pathways of energy, ca ...
... 1995; Schramm 1996). These inherent differences may influence the way that different plant types respond to environmental changes (for example eutrophication), but we also expect that they affect the fate of organic matter produced during photosynthesis and, thus, modify major pathways of energy, ca ...
Effects of Cattle Grazing on the Food Grasslands National Park, Saskatchewan
... used management tool; its impact on grasslands birds has been studied, however, its impact on the invertebrate food sources of grassland birds is less well-known. I examined the effects of cattle grazing on the abundance, richness, and diversity of invertebrates on the mixed grass prairie, and measu ...
... used management tool; its impact on grasslands birds has been studied, however, its impact on the invertebrate food sources of grassland birds is less well-known. I examined the effects of cattle grazing on the abundance, richness, and diversity of invertebrates on the mixed grass prairie, and measu ...
Community organization in streams: the importance of species
... Creek (Michigan, USA), a hard water stream whose flow regime exhibits low variability (Poff and Ward 1989; Hart and Robinson 1990). Previous field experiments in this stream have demonstrated that interactions between epilithic microalgae and grazing insects are tightly coupled, resulting in strong ...
... Creek (Michigan, USA), a hard water stream whose flow regime exhibits low variability (Poff and Ward 1989; Hart and Robinson 1990). Previous field experiments in this stream have demonstrated that interactions between epilithic microalgae and grazing insects are tightly coupled, resulting in strong ...
Columbia River Food Web Report
... Figure C.7.3. Modern pesticide use in the U.S. portion of the Columbia Basin normalized to area (kg/km2) for 246 compounds (average 1999‐2004)................................................................................................................................. 124 Figure D.1.1. Ecologic ...
... Figure C.7.3. Modern pesticide use in the U.S. portion of the Columbia Basin normalized to area (kg/km2) for 246 compounds (average 1999‐2004)................................................................................................................................. 124 Figure D.1.1. Ecologic ...
definitions of harmful alteration, disruption or destruction (hadd)
... effects. For example, structural complexity (expressed as shoot density) generally increases from edge of patches to the interior. Some studies report a lower fish species richness in edge compared to core regions of larger beds, but constant species richness over all regions of smaller beds, in whi ...
... effects. For example, structural complexity (expressed as shoot density) generally increases from edge of patches to the interior. Some studies report a lower fish species richness in edge compared to core regions of larger beds, but constant species richness over all regions of smaller beds, in whi ...
Canopy facilitates seaweed recruitment on subtidal temperate reefs
... et al. 2008; Bulleri 2009). However, very few studies have tested plant facilitation in subtidal ecosystems (Bulleri 2009) and a long standing paradigm about the ubiquity of competitive interactions has developed from a few seminal papers which have demonstrated strong competitive effects, albeit ac ...
... et al. 2008; Bulleri 2009). However, very few studies have tested plant facilitation in subtidal ecosystems (Bulleri 2009) and a long standing paradigm about the ubiquity of competitive interactions has developed from a few seminal papers which have demonstrated strong competitive effects, albeit ac ...
an article online about the origins of the algae
... The effort required to detect a rare diatom taxon in sediment cores is seldom put forth, which may lead to erroneous conclusions about the diatom’s absence. An example that may be analogous to D. geminata blooms comes from the lake diatom Stephanodiscus binderanus, which was initially identified as ...
... The effort required to detect a rare diatom taxon in sediment cores is seldom put forth, which may lead to erroneous conclusions about the diatom’s absence. An example that may be analogous to D. geminata blooms comes from the lake diatom Stephanodiscus binderanus, which was initially identified as ...
Answer Key - Mandarin High School - Mrs. Brand`s Science Classes
... that any newborn fish will be easily distinguishable from the others––then birth will not be a factor. Thus, the population is closed. While closed populations do not pose nearly as many challenges as open populations, there are a number of ways that even a simple mark-recapture study can be undermi ...
... that any newborn fish will be easily distinguishable from the others––then birth will not be a factor. Thus, the population is closed. While closed populations do not pose nearly as many challenges as open populations, there are a number of ways that even a simple mark-recapture study can be undermi ...
Examining Cause and Effect
... Mussels are an important food source for several different kinds of animals, including river otters and raccoons, as well as several fish species. Mussel shells form an important substrate to which algae and insect larvae attach themselves. (A substrate is an underlying surface on which other organi ...
... Mussels are an important food source for several different kinds of animals, including river otters and raccoons, as well as several fish species. Mussel shells form an important substrate to which algae and insect larvae attach themselves. (A substrate is an underlying surface on which other organi ...
Mangrove Workshop Manual - Smithsonian Environmental
... Mangroves are critical, not only for sustaining biodiversity in these intertidal swamps, but also for their direct and indirect benefit to human activities. Energy and nutrients are assimilated and stored in leaves of mangrove trees. As a detritus-based ecosystem, leaf litter from these trees provid ...
... Mangroves are critical, not only for sustaining biodiversity in these intertidal swamps, but also for their direct and indirect benefit to human activities. Energy and nutrients are assimilated and stored in leaves of mangrove trees. As a detritus-based ecosystem, leaf litter from these trees provid ...
United States Department of the Interior
... adult longfin smelt occupy water at temperatures from 16 to 20 °C (61 to 68 °F), with spawning occurring in water with temperatures from 5.6 to 14.5 °C (41 to 58 °F) (Wang 1986, pp. 6–9). Longfin smelt usually live for 2 years, spawn, and then die, although some individuals may spawn as 1- or 3-year ...
... adult longfin smelt occupy water at temperatures from 16 to 20 °C (61 to 68 °F), with spawning occurring in water with temperatures from 5.6 to 14.5 °C (41 to 58 °F) (Wang 1986, pp. 6–9). Longfin smelt usually live for 2 years, spawn, and then die, although some individuals may spawn as 1- or 3-year ...
Benthic protists: the under-charted majority
... planktonic protists. Despite our limited knowledge of benthic protists, there is strong agreement among microbial ecologists that marine coastal sediments play a pivotal role for the diversity and dynamics of overlying plankton communities by acting as seedbanks (Marcus and Boreo 1998). The benthic ...
... planktonic protists. Despite our limited knowledge of benthic protists, there is strong agreement among microbial ecologists that marine coastal sediments play a pivotal role for the diversity and dynamics of overlying plankton communities by acting as seedbanks (Marcus and Boreo 1998). The benthic ...
Benthic protists: the under
... planktonic protists. Despite our limited knowledge of benthic protists, there is strong agreement among microbial ecologists that marine coastal sediments play a pivotal role for the diversity and dynamics of overlying plankton communities by acting as seedbanks (Marcus and Boreo 1998). The benthic ...
... planktonic protists. Despite our limited knowledge of benthic protists, there is strong agreement among microbial ecologists that marine coastal sediments play a pivotal role for the diversity and dynamics of overlying plankton communities by acting as seedbanks (Marcus and Boreo 1998). The benthic ...
Richness–productivity relationships between trophic levels in a
... the MIH is correct, abundance and richness within a trophic level should respond similarly to productivity. In a two-trophic-level system, we predict that consumer richness will increase with increasing productivity but that prey richness will be unrelated to increasing productivity. Support for the ...
... the MIH is correct, abundance and richness within a trophic level should respond similarly to productivity. In a two-trophic-level system, we predict that consumer richness will increase with increasing productivity but that prey richness will be unrelated to increasing productivity. Support for the ...
Napa River Basin Limiting Factors Analysis FINAL TECHNICAL REPORT
... channel (about 10 miles) and to describe current habitat (for salmon, freshwater shrimp, and steelhead) and geomorphic conditions, and changes in channel form between 1940's and present. We found that pool filling with fine sediment is typically quite low with values less than 10 percent at 25 of 29 ...
... channel (about 10 miles) and to describe current habitat (for salmon, freshwater shrimp, and steelhead) and geomorphic conditions, and changes in channel form between 1940's and present. We found that pool filling with fine sediment is typically quite low with values less than 10 percent at 25 of 29 ...
What is a Trophic Cascade? - College of Forestry
... proposing this distinction is not to promote a regressive, dichotomous view of trophic control of communities and ecosystems, but rather to distinguish between trophic processes in which the distribution and abundance of species are controlled by the negative influences of consumers on their prey on ...
... proposing this distinction is not to promote a regressive, dichotomous view of trophic control of communities and ecosystems, but rather to distinguish between trophic processes in which the distribution and abundance of species are controlled by the negative influences of consumers on their prey on ...
Taphonomic signatures and paleoecology of holocene diatom
... This study constitutes the first evaluation of the fragmentation from an entire Holocene diatom assemblages, including centric and araphid pennate taxa which were not evaluated through earlier methods (Konfirst & Scherer, 2012). Additionally, this study is also the first to evaluate two taphonomic v ...
... This study constitutes the first evaluation of the fragmentation from an entire Holocene diatom assemblages, including centric and araphid pennate taxa which were not evaluated through earlier methods (Konfirst & Scherer, 2012). Additionally, this study is also the first to evaluate two taphonomic v ...
River ecosystem

The ecosystem of a river is the river viewed as a system operating in its natural environment, and includes biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions.River ecosystems are prime examples of lotic ecosystems. Lotic refers to flowing water, from the Latin lotus, washed. Lotic waters range from springs only a few centimeters wide to major rivers kilometers in width. Much of this article applies to lotic ecosystems in general, including related lotic systems such as streams and springs. Lotic ecosystems can be contrasted with lentic ecosystems, which involve relatively still terrestrial waters such as lakes and ponds. Together, these two fields form the more general study area of freshwater or aquatic ecology. The following unifying characteristics make the ecology of running waters unique from that of other aquatic habitats. Flow is unidirectional. There is a state of continuous physical change. There is a high degree of spatial and temporal heterogeneity at all scales (microhabitats). Variability between lotic systems is quite high. The biota is specialized to live with flow conditions.↑ ↑ ↑ ↑