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71.
Current evidence suggests regular overland transport of different freshwater invertebrates by wind, mainly over short distances.
Yet, very little is known about the mechanism and scale of this process or about differences in wind dispersal dynamics and
capacities among taxa and propagule types. We investigated wind dispersal of freshwater invertebrates in a cluster of temporary
rock pools (spatial scale: 9,000 m2) in South Africa. Dispersing propagules and propagule bank fragments (i.e. aggregates of sediments and propagules) were intercepted
during 1 month using a combination of windsocks (1.5 m above ground level) and sticky traps (ground level). The potential
movement of propagule bank fragments (i.e. aggregates of propagules and sediments) was also simulated by tracking inter-pool
movements of differently sized artificial substrate fragments similar to dry propagule bank fragments. We detected differences
in the composition of dispersing communities intercepted at different altitudes (ground level and at 1.5 m). Comparison of
dispersal distance distributions also revealed significant differences among taxa. Overall, larger propagule types (e.g. adult
ostracods and oribatid mites) dominantly travelled near ground level while small resting eggs and cryptobiotic life stages
of copepods were most frequently collected at higher altitudes (1.5 m) and dispersed over the longest distances. Finally,
not only dispersal of single propagules but also ground level transport of propagule bank fragments was shown to contribute
to local dispersal dynamics in temporary aquatic habitats. 相似文献
72.
Plant Molecular Biology - 相似文献
73.
Marion Liberloo Martin Lukac Carlo Calfapietra Marcel R. Hoosbeek Birgit Gielen Franco Miglietta Giuseppe E. Scarascia-Mugnozza Reinhart Ceulemans 《The New phytologist》2009,182(2):331-346
A poplar short rotation coppice (SRC) grown for the production of bioenergy can combine carbon (C) storage with fossil fuel substitution. Here, we summarize the responses of a poplar ( Populus ) plantation to 6 yr of free air CO2 enrichment (POP/EUROFACE consisting of two rotation cycles). We show that a poplar plantation growing in nonlimiting light, nutrient and water conditions will significantly increase its productivity in elevated CO2 concentrations ([CO2 ]). Increased biomass yield resulted from an early growth enhancement and photosynthesis did not acclimate to elevated [CO2 ]. Sufficient nutrient availability, increased nitrogen use efficiency (NUE) and the large sink capacity of poplars contributed to the sustained increase in C uptake over 6 yr. Additional C taken up in high [CO2 ] was mainly invested into woody biomass pools. Coppicing increased yield by 66% and partly shifted the extra C uptake in elevated [CO2 ] to above-ground pools, as fine root biomass declined and its [CO2 ] stimulation disappeared. Mineral soil C increased equally in ambient and elevated [CO2 ] during the 6 yr experiment. However, elevated [CO2 ] increased the stabilization of C in the mineral soil. Increased productivity of a poplar SRC in elevated [CO2 ] may allow shorter rotation cycles, enhancing the viability of SRC for biofuel production. 相似文献
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The nucleotide sequence of the S RNA of Impatiens necrotic spot virus, a novel tospovirus. 总被引:4,自引:0,他引:4
P de Haan A C de Avila R Kormelink A Westerbroek J J Gielen D Peters R Goldbach 《FEBS letters》1992,306(1):27-32
Impatiens necrotic spot virus (INSV) shares a number of properties with tomato spotted wilt virus (TSWV), the type species of the genus tospovirus within the family Bunyaviridae. INSV, however, differs from TSWV in plant host range and serology. In order to define the genomic structure and the taxonomic status of this TSWV-like virus, the nucleotide sequence of its genomic S RNA segment has been determined. The molecular data obtained demonstrate that, like TSWV, INSV has an ambisense S RNA molecule, encoding a non-structural protein in viral sense and the nucleocapsid protein in viral complementary sense. The level of nucleotide sequence homology between their S RNAs, as well as the divergence in amino acid sequence homology of their gene products, confirm previous conclusions from serological studies that INSV and TSWV represent distinct virus species within the newly created genus, tospovirus. 相似文献
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