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Uta Cascorbi 《Landscape Ecology》2007,22(9):1371-1381
Theories regarding the establishment and persistence of self-naturalising alien species can help in interpreting these processes
in designed plant communities with their combination of exotic species and native plant communities. Thus, they may provide
a theoretical basis for this kind of landscape design. A case study investigated the influence of plant community conditions
(invasibility), species-specific traits (invasiveness), and gap diameter size on the establishment of selected North American
prairie forbs in Central European horticultural meadows. Experimental sites were located in Freising, Bavaria. Introduced
forbs included Aster laevis, Aster novae-angliae, Aster x salignus, and Aster x versicolor. Establishment success was measured as survival rate and total aboveground dry biomass. Invasibility of the investigated
horticultural meadows was strongly related to resource availability, as most influences of plant community traits could ultimately
be attributed to this factor. Leaf area and specific leaf area above canopy height of the resident meadow species appear to
be the traits that best explained differences in establishment success of the Asters. Gap size influenced species performance mainly on the less productive site, again due to higher availability of resources
in the larger gaps. These results are consistent with findings of studies on self-naturalising alien species. By applying
this interdisciplinary approach, valuable insights in the functioning of designed plant communities could be gained. Horticultural
meadows can be one important tool in designing the highly dynamic urban landscape. In choosing suitable sites, resource availability
should be strongly considered. 相似文献
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Disturbances favour plant invasions because they provide a pulse of resources for seedling establishment and growth. However, little attention has been paid to the importance of the different disturbance regimes in the extent of invasion. In this paper we asked to what extent invasion depends on spatial and temporal patterns of disturbance. By using the spatially explicit model Fateland, we simulated how Cortaderia selloana, a large-wind dispersed perennial grass invading Mediterranean grasslands, responds to different medium-term (up to 55 years) disturbance regimes. The different scenarios combine disturbance frequency, extent of disturbance and temporal and spatial disturbance variability, and they roughly mimic real situations of habitat management and disturbances in cultural landscapes.The model predicted that the proportion of invaded area would increase with disturbance frequency. The extent of the disturbance overcame the importance of frequency. Aggregated disturbances randomly distributed in space had a more positive effect on invasion than scattered disturbances at repeatedly fixed locations. Whether the disturbances regularly occurred in time or were irregularly distributed did not influence the percentage of invaded landscape. Our simulation analysis unambiguously supports the hypothesis that disturbances are essential for the persistence and expansion of Cortaderia sellona. The high amount of seed rain from a few individuals (e.g., gardens) make this species very sensitive to landscape changes produced by different disturbance patterns (e.g., land abandonment, habitat management or rubbish dumping). Our results can contribute to redirect land management options. 相似文献
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Land-use and socio-economic correlates of plant invasions in European and North African countries 总被引：17，自引：0，他引：17
Biological invasions are causing significant ecological impacts and economical costs world-wide. Human activities are the primary cause of this conservation and environmental problem. We conducted a stepwise regression analysis between several land-use and socio-economic parameters and the density of alien species in European and North African countries. We found that the parameters that best explained the density of alien plants were the Human Development Index and imports. The extent of terrestrial transport networks and the percentage of protected areas were the land-use variables that best accounted for the density of alien plants. If we are going to influence policies dealing with biological invasions, more emphasis should be placed on the analysis of land-use and socio-economic determinants at different spatial scales and their changes throughout time. 相似文献
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Emmanuelle Sebert-Cuvillier Valérie Simon-Goyheneche Frédéric Paccaut Olivier Chabrerie Olivier Goubet Guillaume Decocq 《Landscape Ecology》2008,23(7):787-801
The effect of environmental heterogeneity on spatial spread of invasive species has received little attention in the literature.
Altering landscape heterogeneity may be a suitable strategy to control invaders in man-made landscapes. We use a population-based,
spatially realistic matrix model to explore mechanisms underlying the observed invasion patterns of an alien tree species,
Prunus serotina Ehrh., in a heterogeneous managed forest. By altering several parameters in the simulation, we test for various hypotheses regarding
the role of several mechanisms on invasion dynamics, including spatial heterogeneity, seed dispersers, site of first introduction,
large-scale natural disturbances, and forest management. We observe that landscape heterogeneity makes the invasion highly
directional resulting from two mechanisms: (1) irregular jumps, which occur rarely via long-distance dispersers and create
new founder populations in distant suitable areas, and (2) regular, continuous diffusion toward adjacent cells via short-
and mid-distance vectors. At the landscape scale, spatial heterogeneity increases the invasion speed but decreases the final
invasion extent. Hence, natural disturbances (such as severe storms) appear to facilitate invasion spread, while forest management
can have contrasting effects such as decreasing invasibility at the stand scale by increasing the proportion of light interception
at the canopy level. The site of initial introduction influences the invasion process but without altering the final outcome.
Our model represents the real landscape and incorporates the range of dispersal modes, making it a powerful tool to explore
the interactions between environmental heterogeneity and invasion dynamics, as well as for managing plant invaders.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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