Fresh water Ben thic Ecosystems docx

[...]... The Niche of Freshwater Benthic Algae A The Role of Benthic Algae in Ecosystems B How Are Algae in Benthos and Plankton Different? III Methods for Characterizing Freshwater Benthic Algae A Population and Community Structure B Population and Community Function IV Conceptual Frameworks for Benthic Algal Community Ecology References I THE DIVERSITY OF BENTHIC ALGAE AND THEIR HABITATS IN FRESH WATERS A The... PATTERNS OF BENTHIC ALGAE tX AOUATIC ECOSYSTEMS This Page Intentionally Left Blank An Introduction to Algal Ecology in Fresh water Ben thic Habitats R Jan Stevenson Department of Biology University of Louisville Louisville, Kentucky 40292 I The Diversity of Benthic Algae and Their Habitats in Fresh Waters A The Taxonomic and Morphological Diversity of Benthic Algae B The Habitats of Freshwater Benthic Algae... THREE THE NICHE OF BENTHIC ALGAE IN FRESHWATER ECOSYSTEMS 17 The Role of Periphyton in Benthic Food Webs Gary A Lamberti I Introduction 533 Contents xvii II Structure of "Macroscopic" Benthic Food Webs 535 III Periphyton in Aquatic Energy Budgets 536 IV Periphyton in Benthic Food Webs 539 A Fate and Utilization 539 B Are Benthic Grazers Food-Limited? 545 C Other Associations between Benthic Plants and Animals... taxa, and finally to stalked, filamentous, or motile benthic algae B The Habitats of Freshwater Benthic Algae Freshwater benthic algae are found in the photic zones of streams and rivers, lakes, and wetlands Many terms are used to distinguish the groups of benthic organisms that live in different aquatic habitats In the following discussion, terms for benthic algae and associated organisms are defined according... tubes for diatoms (Fig 1) Benthic algal growth forms are hypothesized to confer competitive advantages during different stages of benthic algal community develop- 6 R Jan Stevenson FIGURE I Growth forms of benthic algae Upper left, adnate Navicula (x2400); upper right, apically attached Synedra (x2000); lower left, the filamentous diatom Aulacoseira I Algal Ecology in Freshwater Benthic Habitats 7 entangled... Limitation of Benthic Algae 196 A Patterns 196 B Growth-Limiting Concentrations and Ratios of Nand P 197 C Overriding Effects of Light, Disturbance, and Grazing 206 D Nutrients and Species Composition 207 V Nutrient Kinetics of Benthic Algae 208 VI Effects of Water Motion on Benthic Algal Nutrient Uptake and Nutrient-Limited Growth 212 A Positive Effects of Water Motion 212 B Negative Effects of Water Motion... reproduction in any form reserved 4 R Jan Stevenson other Benthic algae are those that live on or in association with substrata Phytoplankton are algae suspended in the water column An individual alga may be benthic or planktonic at one time or another, but many species are characteristically found in just one habitat Most benthic algae in freshwater ~ habitats are blue-green algae (Cyanophyta), green... of algae can occur in freshwater benthic habitats The Chrysophyta, Xanthophyta, Cryptophyta, and Pyrrophyta have many species that usually occur in the phytoplankton, but they may also occur in physiologically active forms in some benthic habitats In addition, resting cells of many algae can be found in the benthos, which may have originated there or may have settled from the water column (Sicko-Goad... cryptomonads, and dinoflagellates are commonly found in benthic habitats, where they move by means of flagella A few benthic algae, particularly chrysophytes, may be amoeboid Few species of colonial green algae with flagella actually occur in motile form in benthic habitats, but Gonium, Pandorina, Eudorina, and even Volvox may occur incidentally in some benthic algal samples Desmids, a family of green algae... Supply 612 B Nutrient Uptake from Stream Water 614 C Nutrient Remineralization 620 III Indirect Effects 621 A Formation of Boundary Zones 621 B Effects of Algal-Herbivore Interactions 627 IV Nutrient Turnover Rates and Comparison with Other Ecosystems 630 V Summary and Conclusions 632 References 633 20 Benthic Algae and Nutrient Cycling in Lentic Freshwater Ecosystems Robert G Wetzel I Introduction . of Benthic Algae and Their Habitats in Fresh Waters 3 A. The Taxonomic and Morphological Diversity of Benthic Algae 3 B. The Habitats of Freshwater Benthic. Freshwater Benthic Algae 8 II. The Niche of Freshwater Benthic Algae 10 A. The Role of Benthic Algae in Ecosystems 10 B. How Are Algae in Benthos and