Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download wetland slides 8
Document related concepts
Transcript
QUIZ #8 1. Draw the IDH curve. When and why is species diversity highest according to IDH? 2. Explain how anthropogenic disturbance can be either beneficial or detrimental. 3. How can wetlands function as a transitional community (zone) between open lakes and upland terrestrial forest habitats? 4. What is the difference between (or define, up to you) allogenic and autogenic succession. 5. Give an example of both primary and secondary succession. PRIMARY PRODUCTIVITY RANGE OF PRODUCTIVITY: CLIMATE AND LOCAL ENVIRONMENTAL VARIABLES SECONDARY PRODUCTIVITY PLANT AND ANIMAL ADAPTATION Forces leading to adaptation 1. 2. 3. 4. Anoxia: lack of oxygen Salinity: fluctuating or high salinity Soil toxins: sulfide, methane, etc. Nutrient stress: low nitrogen or phosphorus availability 5. Submergence: anchorage, locomotion, change in C source, wave energy, light 6. Herbivory/Predation Responses to anoxia at different levels of complexity Bacteria • alternative respiratory pathways • utilize energy in reduced compounds (e.g. NH4+, CH4, S-) Plants • arenchymous tissue (ethylene production), lenticels, adventitious roots, stem elongation, shallow rooting, hypertrophy, carbohydrate storage structures • pressurized gas flow, radial oxygen loss • Alcohol dehydrogenase(ADH) accumulation Animals • specialized respiratory structures (gills, parapodia, etc.) • pigments • various other physiological and behavioral modifications Responses salt stress at different levels of complexity Bacteria • accumulation of “non-lethal” ions (e.g. K+ relative to Na+) • compatible (organic) solutes Plants • salt exclusion • salt excretion • storage in vacuoles or senescent tissues • C4 instead of C3 photosynthetic pathway Animals • osmoregulate • osmoconform OXYGEN STRESS: ANAEROBIC RESPIRATION OXYGEN PUMPING Illustration of gas flow in the water lily Pressurized gas flow is a function of water depth FLOODING TOLERANCE Loblolly pine root Flooded vs. Nonflooded and ethylene production Loblolly pine seedling stem Mangrove Adaptations waxy leaves and viviparous seedlings lenticels specialized root structures salt exclusion vs. salt excretion Mangroves are better competitors in salty environments NH4+ uptake SOIL PHYTOTOXINS: IMPACT NUTRIENT UPTAKE Vmax Km NH4+ concentration EFFECTS OF POREWATER SALINITY NH4+ uptake Vmax Km NH4+ concentration Spatial Gradients High tide low tide increasing soil salinity, and sulfide concentrations decreasing soil redox Reciprocal effects of vegetation on soil SALT MARSH COMMUNITY STRUCTURE PHOTOSYNTHETIC PATHWAYS C3 PATHWAY C4 PATHWAY Stomata imprints on underside of red mangrove leaf Measuring photosynthesis and transpiration in a mangrove forest Definitions tolerator (conformer): an organism that has functional modifications allowing it to survive and often function in the presence of stress. regulator: organisms that actively avoid stress or modify it to minimize its effects (e.g. thermoregulator, osmoregulator, etc.) SALT STRESS IN ANIMALS Reptilian tolerance to anoxia NEKTON ADAPTATIONS Estuarine-dependent life cycles Brown shrimp Gulf menhaden Seasonal occurrence of estuarine-dependent species Quiz # 8 1. Why is nitrogen fixation inhibited by aerobic conditions? 2. Describe one way in which bacteria deal with anoxia. 3. Describe a mechanism that allows hydrophytes to deal with salinity stress. 4. What is the source of inorganic carbon for plants photosynthesizing under water (i.e., SAV)? 5. What microbial process gives rise to reduced inorganic nitrogen?
