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Болота и лужи.

Болота. Размерные спектры.


Freshwater Biology

Volume 46 Issue 10 Page 1373 - October 2001



Size distribution of aquatic invertebrates in two prairie wetlands, with and without fish, with implications for community production

Kyle D. Zimmer, Mark A. Hanson, Malcolm G. Butler & Walter G. Duffy

1.We compared the size distribution of aquatic invertebrates in two prairie wetlands,

one supporting a population of fathead minnows and the other fishless. Both

wetlands were sampled in three depth zones on three dates, allowing assessment of

temporal and spatial variation.

2.We determined biomass of aquatic invertebrates in 17log2 size classes, and used

these data to develop normalized size spectra. We also coupled size distributions

with an allometric model to estimate relative production at the community level.

3.The composition of the invertebrate communities differed greatly between sites,

and invertebrate biomass was higher in nearly all size classes in the fishless wetland.

Intercepts of normalized size spectra were significantly different between wetlands,

but slopes generally were not, indicating differences in standing-stock biomass but

similar size structures between the two invertebrate communities. Higher standing-

stock biomass in the fishless wetland resulted in higher relative production per unit

area, but similar size distributions resulted in similar mass-specific production (P/B)

between wetlands.

4.Our results indicate that invertebrate communities in prairie wetlands may have

relatively consistent size structures in spite of large differences in community

composition and standing-stock biomass. We hypothesize that the observed

differences are because of predation by the minnow population and/or differences

in the macrophyte communities between the two sites. However, the relative

importance of macrophytes and fish predation in structuring invertebrate

communities in prairie wetlands is poorly known.



Болота: факторы заселения беспами.


Freshwater Biology

Volume 45 Issue 3 Page 295 - November 2000



Factors influencing macroinvertebrate colonization of seasonal wetlands:

responses to emergent plant cover

Ferenc A. De Szalay and Vincent H. Resh

1.We conducted field experiments to examine factors influencing macroinvertebrate

colonization of seasonally flooded marshes. Few macroinvertebrate species were

found aestivating in soils within non-flooded wetlands indicating that most taxa

colonize these marshes from other flooded habitats.

2.We manipulated amounts of salt grass (Distichlisspicata) to examine how

emergent plant cover affects aerial colonization by macroinvertebrates. Areas

mowed 3 weeks before flooding had low plant cover, areas mowed 5 and 9 weeks

before flooding had medium and high plant cover, respectively, and non-mowed

control areas had the most plant cover. Macroinvertebrate numbers and biomass

were generally higher in mowed treatment areas than in control areas, but overall

diversity was generally higher in high plant cover and control areas than in low plant

cover areas.

3.Mosquitoes (Culicidae), brine flies (Ephydridae) and hover flies (Syrphidae) were

positively correlated with amount of plant cover, and waterboatmen (Corixidae),

midges (Chironomidae) and water scavenger beetles (Hydrophilidae) were

negatively correlated with plant cover. Species assemblages changed seasonally

among treatment areas because these taxa colonize wetlands at different times in the

year.


4.These results demonstrate that invertebrate communities may be different within

plant stands with heterogeneous amounts of emergent cover, and management

practices that alter the structure of wetland vegetation can influence

macroinvertebrate communities colonizing seasonal marshes.




Водотоки: распределние семейств бентоса.


Fresh Water Biology Volume 41 Issue 2 Page 299 - March 1999

Patterns of distribution of macroinvertebrate families in rivers

of north-western Australia

W. R. Kay*, M. J. Smith*, A. M. Pinder*, J. M. Mcrae*, J. A. Davis and S. A. Halse*

Summary

1. The northern half of Western Australia is a large, sparsely populated area with a



climate that ranges from monsoonal in the Kimberley to arid in the Gascoyne and

Pilbara regions. The aquatic invertebrate fauna is poorly known.

2. Fifty-one sites located on 14 river systems were sampled three times between

August 1994 and October 1995. A total of 90 taxa, most identified to family level,

were collected. The fauna was dominated by insects, which constituted 74% of the

total number of taxa collected.

3. Major habitats at each site were sampled separately and sites with more habitats

tended to have a richer fauna. All habitats showed significant differences in

taxonomic richness between regions. Family richness decreased with increasing

latitude, being highest in the Kimberley region and lowest in the Gascoyne.

4. Despite the differences in taxon richness between regions, community

composition of the aquatic invertebrate fauna at the family level did not differ

greatly. Four major groups of sites were identified by cluster analysis, based on the

invertebrate families present at each site, but differences between groups were

small.

5. Significant temporal variation in taxon richness was found in channel habitat but



not the three other habitats sampled (riffle, macrophyte, pool-rocks). Community

composition in channel habitat varied temporally among groups of sites identified

by cluster analysis but the pattern was not consistent.

Заселение лужи, Испания


02.06-04А2.289. Сукцессия сообщества макробеспозвоночных во временном пруду. Succession of the macroinvertebrate community in a temporary pond : Докл. _[27 Congress of the International Association of Theoretical and Applied Limnology, Dublin, 1998_] / Boix D., Sala J., Moreno-Amich R. // Verh. / Int. Ver. theor. und angew. Limnol. - 2001. - 27, № 5. - С. 2586_ѕ2593. - Англ.

Исследования проводили в пруду, расположенном в р-не карста, площадь зеркала 3,13 га, макс. глубина 4 м (Пиренейский п-ов). Доминировали Triops cancriformis и Fossaria truncatula во время весеннего и зимнего циклов. Остальные представители были различны во время этих циклов. Весенний цикл характеризуется колонистами из воздушной среды, зимний _ѕ почвенными животными. При смене циклов наблюдается смена доминирования разных видов кориксид и хирономид. Разнообразие и видовое богатство увеличиваются с продолжительностью периода затопления. Испания, Inst. of Aquatic Ecol. & Dep. of Environmental Sc., Univ. of Girona. Campus de Montilivi, E_ѕ17071 Girona, Catalunya. Ил. 3. Табл. 1. Библ. 38.


Роль РОВ в болоте, Япония


02.01-04А2.130. Роль растворенного органического вещества в экосистемах болотных луж. Significance of dissolved organic matter in a mire pool ecosystem : Докл._[27 Congress of the International Association of Theoretical and Applied Limnology, Dublin, 1998_] / Hanazato T., Hayashi H., Sakai S., Mori M., Kawamura K., Nohara S. // Verh. / Int. Ver. theor. und angew. Limnol. - 2001. - 27, № 3. - С. 1649_ѕ1652. - Англ.

Исследования проводили в центр. Японии в болоте на высоте 1400 м над ур. моря. Опыты ставили в изолированных емкостях в период с июля до октября 1996 г. Пробы брали каждые 2_ѕ3 нед. в изолированных емкостях и вне их. Приведены данные об изменениях т-ры и уровня растворенного органического вещества (РОВ), плотности бактерий, зоопланктона, влиянии УФ. В изолированных емкостях уровень РОВ был ниже, чем вне их. Сниженный уровень РОВ увеличивает подверженность экосистем влиянию УФ-A и УФ-B в изолированных емкостях. Вместе с тем, РОВ _ѕ основной ресурс для роста бактерий, и их плотность вне изолированных емкостей была выше, чем в них. Обсуждается возможное увеличение РОВ при потеплении климата и связанные с этим изменения в экосистемах болот. Япония, Suwa Hydrobiological Station, Shinshu Univ., Suwa 392_ѕ0027. Ил. 6. Библ. 11.




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