Showing papers in "Aquatic Botany in 1993"

TL;DR: A survey of electrophoretic variation in 81 aquatic taxa revealed that the distribution of genetic diversity within and among populations of emergent species, as in their terrestrial counterparts, appears to be determined primarily by their breeding systems and life histories.

TL;DR: In this paper the case for the existence of six major categories of selective forces operating on clonal propagules is presented and it is shown that different methods of clonal reproduction differ in terms of these six characteristics.

TL;DR: Rates of methane emission associated with Florida Typha domingensis Pers.

TL;DR: The effects of light, oxygen and sediment burial on seed germination of Zostera marina L. were tested in two experiments beginning in 1987 and 1988 as mentioned in this paper, where seeds were placed in flow-through clear plastic tubes or buried at depths of 5, 15 and 25 mm in pots filled with seagrass sediments and held in an outdoor running seawater tank at ambient temperature, salinity and solar irradiance.

TL;DR: In large parts of the peaty lowlands of The Netherlands, alkaline, sulphate-enriched river water poor in iron is let in to compensate for decreased ground water levels as discussed by the authors.

TL;DR: A 6-year (1986-1991) study in Water Conservation Area 2A (WCA2A), a remnant portion of the Florida Everglades, was conducted in which multiple plots within six study sites across a surface water nutrient gradient were monitored for water quality, depth, and sawgrass (Cladium jamaicense Crantz) and cattail (Typha domingensis Pers.) densities.

TL;DR: Dispersal between populations is likely to be a rare event in southeastern Australia because of low numbers of floating propagules, the discontinuous distribution of habitat and the hazards of recruitment, and recovery from mass mortality within an estuary will be slow.

TL;DR: It was concluded that macrophytes were able to grow on all substrates present in Lake Vaeng, but waterfowl grazing probably controlled and delayed macrophyte colonization.

TL;DR: Two important evolutionary factors, hybridization and chromosome number variation, are discussed with respect to interactions involving clonal growth, vagility, and asexuality in aquatic angiosperms.

TL;DR: Grazing by invertebrates was negligible in the inner part and allowed biomass accumulation, whereas grazing pressure in the outer part matched the growth rate during summer and exceeded it by more than two-fold during autumn.

TL;DR: A synthesis of knowledge on the lower-level trophic pathways in this system indicates that seagrass-urchin and periphyton-epifauna grazing interactions are both important in their contribution to overall Trophic flux.

TL;DR: The seasonal dynamics of above and belowground biomass of Zostera noltii Hornem were studied in a permanent quadrat in the Palmones River estuary, southern Spain (36° 11′ N, 5° 27′ W) from February 1988 to February 1990 as mentioned in this paper.

TL;DR: Variations in the level of UV-absorbance relative to chlorophyll in Prasiola, appear to correspond with varying UV exposure, suggesting that even for Antarctic algae, that contain high levels of ultraviolet-absorbing pigments, exposure to sunlight with an increased ratio ofUV-B to visible light is stressful.

TL;DR: Preliminary studies of aquatic plants in numerous tropical aquatic habitats in Costa Rica indicate a low level of diversity, and such a level of species richness appears to be in direct conflict with the general viewpoint that tropical ecosystems are exceedingly diverse.

TL;DR: Four hydrophilous species have been studied using allozyme estimates of variation within and among populations and show much greater partitioning of variation among populations than non-hydrophiles, particularly when compared with anemophilousspecies.

TL;DR: The dynamics of the seeds, seedlings and mature shoots were studied for two seagrass species at seven elevations on an intertidal site in the southwestern Netherlands from the autumn to the following summer.

TL;DR: In this paper, a generic simulation model for the dynamics of submerged macrophytes is presented, called MEGAPLANT (Model Evaluating General Aquatic Pland Laws And New Theories).

TL;DR: Primary production of tropical seagrass meadows was studied between April and August 1990 in South Sulawesi, Indonesia and the suitability of different methods to measure seagRass productivity is evaluated.

TL;DR: The genetic diversity of stable and declining stands of Phragmites australis (Cav.) Trin.

TL;DR: The immediate interface between the root cell wall and the iron plaque of Vallisneria americana Michx (wild celery), a submerged freshwater plant collected in lakes of the St. Lawrence River system, Quebec, Canada, was examined and revealed the presence of Mn-rich particles in the plaque.

TL;DR: Light and temperature requirements higher than 15°C were found to be necessary for successful seed germination in laboratory studies; however, light was determined not to be a limiting factor on its own.

TL;DR: The major effect of flooding is prevention of germination while mudflats are under water, since seeds do not enter dormancy in spring or summer, and they can germinate any time during the growing season if the Mudflats become exposed.

TL;DR: Three cohorts of seedlings of Phragmites australis (Cav.) Trin ex Steud.

TL;DR: Flowering, fruiting and seed germination of the seagrass Cymodecea nodosa (Ucria) Ascherson are recurrent in the Mar Menor coastal lagoon and other places on the southeast Mediterranean coast of Spain and the effect of water movement on the fate of seed production is discussed.

TL;DR: Growth and drought tolerances of three common freshwater wetland grasses, Panicum hemitomon Schult, Manisuris rugosa (Nutt.) Kuntze, and Leersia hexandra Sw.

TL;DR: Ambient photosynthetic rates and initial slopes of the CO 2 -photosynthesis curves of amphibious plants were similar to those of aquatic plants and were lower than values for terrestrial plants, and Photosynthetic performance of aquatic, amphibious and terrestrial plants showed no parallel variation with chlorophyll content.

TL;DR: More research is needed to qualify whether intensive photosynthetic activity is a common phenomenon in emersed intertidal seagrass populations and how significant this process is for the carbon balance of these plants.

TL;DR: In this paper, plant community development and phytosociology on mudflats on two inner deltaic splays in the Mississippi River delta, Louisiana, are described and three communities based upon plant species occurrence, soil, and plant biomass data collected over seven growing seasons.

TL;DR: Feeding experiments revealed that adult weevils can reduce watermilfoil growth, and that they concentrate their feeding activity on the stem and leaves at the tops of plants.