Journal of Vegetation Science

In the Altai Mountains of southern Siberia, we discovered pine-birch forests which contain up to 114 species of vascular plants per 100 square metres, and 149 species per 0.1 ha. About 95% of their vascular plant species occur in the herb layer and all species are native. They are probably the most species-rich forests in boreal and temperate Eurasia.

The influence of livestock grazing on elevational shifts of plant communities was investigated using a sheep grazing enclosure study on a mountain slope. Grassland plant communities shifted upward in the absence of grazing livestock, were constrained by low densities of livestock and moved downwards at high livestock densities. This demonstrates that herbivory can buffer elevational advance of vegetation.

Alpine granite gravel field ecosystems are nationally rare in New Zealand and are known from only two locations. We compared community assembly processes between those two examples and revealed that dominant species converged on a similar narrow range of functional trait values, while rare species harboured a wide range of distinctive trait values and contributed to high trait diversity.

In this work we show that plant species differ in the mechanisms that explain the temporal variation in their abundance. 8/29 populations were found to be endogenous regulated, 4/29 were exogenous regulated and in two cases both factors acted simultaneously. The dynamics of most populations were temporally stable, although in 5/29 populations we suggest the possibility of chaotic dynamics.

We simulated the dynamic colonization and stress of Mississippi River island community assembly, where competition often occurs among cohorts. Older individuals tolerated stress better and accrued more biomass regardless of competition, and first colonizer status gave one species a competitive advantage. This study gives evidence to the impacts of arrival time on subsequent physiological and competitive abilities of plants.

Competition by native dune species on the invader bitou bush is affected by water availability. Many native species have small competitive effects on the invader under droughted conditions. As a result some native species may be less effective competitors and provide less resistance to invasion under water stress.

This work helps to clarify the relative importance of direct versus indirect effects of endophyte infection in tall fescue. It shows that the direct benefits of endophyte infection do not drive competitive responses of tall fescue at the early stages of plant development. Rather, negative plant-soil feedbacks may be more important in moderating plant responses to competitive interactions during seedling establishment of this species.

We hypothesized that endozoochory could reduce the environmental filtering imposed to seedlings to a larger extent than does anemochory. We characterized the relationship between seedlings, saplings and adults with environmental factors for 16 woody species growing in 25 communities in NW Patagonia, Argentina. Our results support the hypothesis and suggest that endozoochory diminish mortality costs during the early stages of recruitment.

Large seeds provide an advantage for seedling survival, but in extreme drought conditions, seedling survival in small-seeded species equals that of seedlings from large-seeded species. Seedlings from larger seeds are larger than those of small-seeded species, but have a lower root/shoot biomass ratio, leading to greater potential evapotranspiration, which could explain their loss of relative advantage under extreme droughts.

Legend: Standard deviations of nearest neighbor distances along a trait axis across two environmental gradients. Triangles and diamonds indicate mean standard deviations of nearest neighbor distances in random communities and observational communities respectively. Solid diamonds indicate significant deviations spacing compared to null model (P<0.05). Plot No. T1-T6 indicate from shrub-end to forest-end at timberline gradient; Plot No. G1-G6 indicate from shrub-end to forest-end at grazing gradient. Note: all functional traits except internode length were natural-log scaled.

Environmental filtering could both result in trait values differences between habitats and different trait scaling relationships (allometric and trade-off constrains) among coexisting species. In dry vs. wet Central European meadows, we observed changing trait scaling with plant height, while trait differentiation within meadows was stronger than environmental filters effects. The results advocate for incorporating trait scaling relationships into vegetation models.

The relative importance of seed availability, seedling establishment, and seedling survival to post-cultivation community recovery was assessed by comparing seeds, seedlings and vegetation. A cultivation legacy on recruitment was still evident 100 years after abandonment, but environmental conditions were not the main cause. Seed and microsite limitation interacted to drive succession, but seed availability was relatively more important.

Using simulated communities, we show that environmental geometry has a strong influence on heterogeneity-diversity relationships (HDRs). Fractal dimension and habitat distribution influence both the strength of HDRs, as well as how quickly they develop. However, idiosyncratic differences among statistically similar landscapes can be substantial. Field studies of HDRs frequently use inadequate sample sizes to account for the influence of environmental geometry.

The mechanisms that allow an exceptionally high number of plant species to co-exist in southwest Australian biodiversity hotspot are linked to the extent to which local dominant plant species are limited by N and P. In addition, on nutrient impoverished soils of southwest Australia, a foliar N:P ratio > 16 can reflect N as well as P limitation.

The biotic homogenisation of vegetation is an important consequence of environmental change. This re-sampling study provides evidence of this process in Scottish upland vegetation over the second half of the twentieth century. The results show a loss of plant diversity at local, community and landscape scales, and suggest that climatic warming and acidification are responsible for the observed vegetation change.relationships into vegetation models.

Jan Mayen is a remote island in the North Atlantic without any direct impact by humans or grazers. In a study of vegetation changes on the island over two different time periods, we observe changes in the vegetation that correspond to observations from other arctic areas with increase in dwarf-shrubs and graminoids and decrease of species linked to snow-beds.

Spatial heterogeneity of fire regime plays more important influence on ecosystem characteristics than fire severity in an eastern boreal landscape of Northeast China. To emulate natural fire effects, delineating landscape into fire management units and incorporate variable fire severities in harvest prescriptions for each unit are necessary.

Extraordinarily high plant species richness is often claimed, but we assemble the world record values from areas 1 mm² - 1 ha. Up to 50 m², all the maxima are in temperate nutrient-poor grasslands; at larger spatial grain all are from tropical rain forest. The maximum values fall closely on a power-law line with a slope of z = 0.25.