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1.
Frauke Kleemann Maximilian von Fragstein Barbara Vornam Annika Müller Christoph Leuschner Andrea Holzschuh Teja Tscharntke Reiner Finkeldey Andrea Polle 《European Journal of Forest Research》2011,130(5):707-716
Knowledge on phenological, morphometric, and phytochemical variation of local progenies of European aspen (Populus tremula, L.) is limited. The goal of this study was to characterize variation in growth and ecologically important leaf properties
in aspen full-sib families in relation to interacting organisms (mycorrhiza, endophytes, and insects) and to determine whether
these interactions were affected by soil application of a systemic fungicide. In local progenies, within-family variation
of neutral molecular genetic markers (nuclear microsatellites) was higher than between families. Significant variation in
growth, production of phenolic defensive compounds and other phytochemical leaf traits was found between families. Phenolic
compounds showed clear negative correlation with generalist herbivores, but did not result in negative trade-off with biomass
production. Differences in mycorrhizal colonization were not found among full-sib families and application of a systemic fungicide
suppressed neither mycorrhizal colonization nor infestation with insects. However, a strong suppression of endophytes occurred,
whose long-term consequences may require attention when fungicides are used in agroforestry plantations. 相似文献
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Kormann Urs G. Scherber Christoph Tscharntke Teja Batáry Péter Rösch Verena 《Landscape Ecology》2019,34(5):1045-1056
Landscape Ecology - Global change pressures (GCPs) imperil species and associated ecosystem functions, but studies investigating interactions of landscape-scale pressures remain scarce. Loss of... 相似文献
4.
In a study conducted in Marmot Creek Basin (total area 9.40 kmz) situated in the Rocky Mountains of Alberta, equations were developed to obtain gross estimates of the total inorganic solutes dislodged from three forest catchments on a monthly and annual basis. The r 2 range of the equations was 99% or greater, indicating excellent fit in all cases. The equations are suitable for in situ estimation of the pollution loads directly from streamflow measurements, especially for remote catchments. 相似文献
5.
Stephanie Sobek Teja Tscharntke Christoph Scherber Susanne Schiele Ingolf Steffan-Dewenter 《Forest Ecology and Management》2009
Bees and wasps provide important ecosystem services such as pollination and biocontrol in crop-dominated landscapes, but surprisingly little information is available on hymenopteran communities in temperate forest ecosystems. Species richness and abundance of bees and wasps can be hypothesised to increase with plant diversity, structural complexity, and availability of food and nesting resources. By experimentally exposing standardised nesting sites, we examined abundance and species richness of cavity-nesting bees (pollinators), wasps (predators) and their associated parasitoids across a tree diversity gradient in a temperate deciduous forest habitat. In addition, spatial distribution of individuals and species across forest strata (canopy vs. understory) was tested. Abundance and species richness was high for predatory wasps, but generally low for pollinators. Species-rich forest stands supported increased abundance, but not species richness, of pollinators and predatory wasps, and also increased abundance and species richness of natural enemies. In addition, the forests showed a distinct spatial stratification in that abundance of bees, wasps and parasitoids as well as parasitism rates were higher in the canopy than understory. We conclude that particularly the canopy in temperate forest stands can serve as an important habitat for predatory wasp species and natural enemies, but not bee pollinators. Enhanced tree diversity was related to increased hymenopteran abundance, which is likely to be linked to an increase in nesting and food resources in mixed forest stands. 相似文献
6.
Armin M Stroebel Matthias Bergner Udo Reulbach Teresa Biermann Teja W Groemer Ingo Klein Johannes Kornhuber 《Journal of circadian rhythms》2010,8(1):10
Background
Animals, including humans, exhibit a variety of biological rhythms. This article describes a method for the detection and simultaneous comparison of multiple nycthemeral rhythms. 相似文献7.
Patrick Hoehn Ingolf Steffan-Dewenter Damayanti Buchori Teja Tscharntke 《Agroforestry Systems》2009,76(1):163-171
Tropical insect species show year-round breeding activity due to favourable climatic conditions. However, most species also
display seasonal reproductive peaks, but little is known about underlying causes of temporal density changes. We investigated
population dynamics of the pest predator Rhynchium haemorrhoidale (F.) (Hymenoptera: Eumenidae) and its natural enemies in relation to season, climate and varying shade tree composition in
cacao agroforestry systems in Central Sulawesi (Indonesia). Nesting of R. haemorrhoidale showed clear seasonality with highest densities in the wet season and lowest in the dry season, which was not related to
changes in temperature. Wasp densities increased with land-use intensity, presumably because less-shaded areas offer more
favourable climatic conditions and higher densities of the major prey, the cacao pest Agathodes caliginosalis (Lepidoptera: Pyralidae). Pupal body size was higher in June than in November indicating increasing intraspecific competition
due to high wasp densities and food shortage at the beginning of the wet season. Body size between habitat types was similar,
thus season appeared to be more important than habitat in terms of food supply. High wasp densities in the wet season were
associated with high diversity of the altogether seven parasitoid species. In conclusion, we found a pronounced seasonality
of the wasp R. haemorrhoidale and a preference for little shaded agroforestry, which may be due to enhanced temperature and density of its prey. Our data
indicate a high potential for biological control of a major cacao pest by management of nesting sites of R. haemorrhoidale. 相似文献
8.
Hedges provide important nesting, feeding and sheltering sites for birds in agricultural areas, while organic farming also enhances farmland birds. However, it is little known how the interaction of these local variables (amount of hedges and organic management) with landscape scale variables affects birds. We selected paired conventional and organic winter wheat fields and meadows in each of 10 landscapes in Germany. Birds were surveyed in the fields and in the adjoining hedges. More bird species occurred in organic than in conventional fields regardless of land-use type (wheat fields and meadows). However, hedge length had a much stronger effect on bird richness than organic farmland management. We found an interaction of landscape complexity and hedge length in that hedge length enhanced bird richness only in case of simple landscapes (<17% semi-natural areas within a 500 m radius around the centre of bird survey plots). In more complex landscapes the local effect of hedge length levelled off because bird richness was high even without local hedges. Therefore, adding hedges or introducing organic farming practices should be primarily promoted in simple landscapes, where it really makes a difference for biodiversity. 相似文献
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The rare pamphiliid waspCaenolyda reticulata (L.) has lately been found in three localities of northern Germany. The subjects parthenogenesis, synanthropy, and setting up endangered species lists (Rote Listen) are discussed. 相似文献
10.
Anne Richter Alexandra-Maria Klein Teja Tscharntke Jason M. Tylianakis 《Agroforestry Systems》2007,69(3):175-182
Shade coffee including many tree species is known to support generally high biodiversity. Due to low coffee prices on the
world market, many farmers have abandoned their farms, thereby creating a new ecosystem type, which has attracted increasing
interest for biodiversity conservation. Here we used pyrethrum knockdown samples to compare the arthropod community on coffee
plants of six traditionally managed coffee agroforests with those of six abandoned coffee agroforests in coastal Ecuador.
We investigated eight randomly selected coffee shrubs per site, six of them inside and two at the edge. All arthropods were
identified to orders and beetles to morphospecies. We additionally sampled the vegetation to test for vegetation-mediated
effects on the arthropod community. The number of arthropod individuals was higher in abandoned than managed coffee, driven
by the abundance of Arachnida, Blattaria, and Heteroptera, and higher in the edge than in the centre of the abandoned agroforests.
Higher arthropod abundance appeared to be closely related to arthropod diversity, as shown for beetles (r = 0.79, n = 96). Contrary to expectations, predator-prey ratios in managed agroforests was as high as in the abandoned ones. In conclusion,
abandonment of coffee agroforests greatly encourages arthropod communities, in particular in the habitat edges, and therefore,
should be considered in landscape management for conservation. 相似文献