Plant Ecology最新文献

Mobility is highly species-specific and individual species mobility can be predicted by species traits, yet this topic remains largely understudied. We analyzed data on species presences/absences in permanent subplots (1m × 1m) within 15 main plots 10m × 10m) over 24 years originating from a grassland biodiversity experiment in Czechia. Plots differed in initial species richness and composition. We estimated mean individual species persistence and searched for any relationship with individual species traits. We also tested the effect of sowing richness/composition on species persistence and community mobility. Our results show that individual species have very different mobilities which vary in time and can be predicted by species traits, most importantly by leaf traits, clonal traits, and traits characterizing species life forms. Trait syndrome corresponding to the traveler part of the mobility gradient typically includes annuals having a taproot, long-lasting seedbank, and high SLA. Trait syndrome of sitters includes perennial hemicryptophytes with effective clonal reproduction and transient seedbank. Importantly, trait association with species mobility is spatial scale dependent, whereas studies on the spatial scale of 0.01m² show that clonality increases mobility, in our case clonality increases the persistence of species in 1m² units. In contrast with an evident linkage between mobility and traits, the effect of community richness/composition on species/community mobility was weak and detectable in the very first years of the experiment only.

Broad-leaved deciduous forests in the transitional region from temperate to subtropical climate in China exhibit a diverse assemblage of species. The effects of potential biotic and abiotic factors on forest species diversity are currently of great interest. Here, we quantified the diversity of woody plant species across vertical strata in a fully recorded 25-ha permanent forest dynamics plot (500 × 500 m) in the Mts. Qinling of China using 4 indices: Pielou evenness index (({J}_{SW})), Shannon entropy ((H)), species richness ((S)), and species abundance. Analysis of multivariate linear regression was employed to compare the influences of potential biological, topography, and soil variables on the alpha diversity for each of the 625 sub-plot (20 × 20 m) in the canopy layer, substory layer, and understory layer. The results displayed that the indices of the alpha diversity significantly varied among different forest vertical strata and they were mostly and significantly related to the DBH structure variable, soil available phosphorus (P), and altitude. Despite vertical strata of the studied forest, biological, topographic, and soil factors jointly showed reasonably strong explanatory power for species diversity. More than 12% of the variations of the alpha diversity in canopy layer and 16% in substory layer as well as 8% in understory layer could be collectively explained by biological, topographic, and soil factors. Our findings can contribute to the understanding of how environmental and biological factors interact to affect species diversity and thus are of great implication for the preservation of forest species diversity.

It has long been hypothesised that introduced species can evolve to become better competitors, which in turn will enable some of them to become invasive. The evolution of increased competitive ability hypothesis (EICA) gives a possible answer for why some introduced plants become invasive by stating that they can escape natural coevolved enemies (pests, pathogens and herbivores) in their new environment, thus allowing them to shift resource allocation from producing expensive chemical defences, towards a higher growth rate and competitive ability. In order to test if there is evidence for increased competitive ability in introduced populations, we examined the performance of three Rumex species (R. obtusifolius, R. crispus and R. conglomeratus, Polygonaceae) from their native (United Kingdom) and introduced ranges (New Zealand), when grown alone and in competition with a conspecific from the same or a different provenance. Based on the predictions of EICA, we hypothesised that plants from the introduced provenance would: (i) have a faster growth rate and a larger biomass at harvest; and (ii) would perform better in competition with a conspecific from the native provenance than one from the introduced provenance. Intraspecific competition reduced biomass by as much as 50%. However, contrary to expectations, we found no difference between the performance of plants from native and introduced provenances when grown in direct competition with each other. Plant performance when grown with a conspecific from the same provenance was similar to performance when paired with one from a different provenance, showing that there was no provenance effect. These results were consistent for all three Rumex species. Our findings contradict the predictions of the EICA hypothesis suggesting that other factors are needed to explain the success of Rumex species in New Zealand.

Shrubs are key components of temperate and boreal ecosystems. Field experiments performed along environmental gradients are useful to study how these species may cope with new climatic conditions. We analyzed the effects of habitat, elevation, and canopy on the performance of the bilberry Vaccinium myrtillus, a key resource for numerous species in boreal and temperate regions of Eurasia. We estimated bilberry dry mass and measured vegetative (ramet height, stem diameter, and shoot production) and reproductive (fruit and seed production) performance of bilberry shrubs in thirty plots located at six study sites established in coniferous forests and subalpine meadows along a 600-m elevation gradient in Tatra National Park, Poland. Although we detected more ramets per plot in the meadows, bilberry dry mass was larger inside the forest, whereas ramets were heavier and taller and produced more annual shoots. A higher proportion of ramets produced fruits in the meadows, where we additionally found a higher proportion of mature seeds per bilberry fruit. When only plots located inside the forest were considered, we detected a negative relation between elevation and bilberry ramet dry mass. Canopy cover affected the number of ramets and the dry bilberry biomass per plot differently depending on the elevation, demonstrating interactive effects of these two variables in bilberry vegetative performance. Fruit production inside the forest was negatively affected by both elevation and canopy cover, while interactive effects of these two variables determined seed development. Bilberry management actions must consider habitat heterogeneity even at small spatial scales and possible interactive effects of environmental variables such as those analyzed in this study.