Journal of Ecology

Our results reveal that loss of a single functionally distinct plant species, such as occurs through herbivore invasion, can cause substantial effects both above-ground and below-ground. This may affect the trajectory of the ecosystem over successional time, especially in primary seres that otherwise have very low soil carbon (C) and nitrogen (N) reservoirs. More generally, our results support the view that the simultaneous gains of some organisms (e.g. invasive herbivorous mammals) and resultant losses of others (e.g. palatable N-fixing plants) is a major element of human-induced global change that may be transforming many communities and ecosystems worldwide.

In contrast to previous studies, the results show that many endophytes do not occur ubiquitously, but instead exhibit both plant and tissue specificity. There is a strong seasonal change in endophyte communities, but the differences between roots and shoots at any one time can be just as large. This dissimilarity suggests a lack of systemic growth by the fungi from one tissue to another. Mycorrhizas may interact negatively with other root endophytes, indicating that the latter should not be ignored in future mycorrhizal studies. We should begin to think of individual plants as ecosystems of interacting microbes, whose community is structured by plant genetics and environmental conditions, coupled with interactions between the microbes themselves.

This is the first study that demonstrates that consumer diversity can influence richness patterns at continental scales, and demonstrates that biotic factors can drive richness even at broad spatial scales.

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We demonstrated two mechanisms by which top-down forces can facilitate macroalgal growth: herbivore nitrogenous waste inputs and removal of microalgal fouling organisms. This facilitation may occur within the large mats of macroalgae that form during bloom events, exacerbating bloom conditions.

Water stress has not selected biomass partitioning differences among seedlings of tree species from semi-arid (open bars) and humid (filled bars) savannas from three continents. High allocation to roots (RMF) and low allocation to stems (SMF) is associated with species of humid environments where fire is more frequent, indicating that selection by fire pressure supersedes any selection in response to water constraints. Species from semi-arid environments have superior root morphology for searching for deep water compared with species of humid environments, including faster taproot extension rates (RER) and more efficient taproot depth penetration (STRL), but they show no difference in mean relative growth rate (RGR).

Little is known about how endemic-rich special soil plant communities will fair under climate change. We assess how spatial isolation, nutrient limitation, stress-tolerant functional traits, and other factors affect serpentine soil communities under climate change. Studies that compare effects on both special and ‘normal’ soil communities will be critical for understanding climate change risk for these botanically-rich communities.

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Our findings reveal an axis of trait variability among desiccation-sensitive seeds that is orthogonal to size. These traits might be important in surviving pre-germination environmental conditions, independent of the advantages and/or disadvantages that size has been shown to confer on seed survival and seedling establishment. The implication of this finding is that seed size alone may not account for pre-germination viability in desiccation-sensitive seeds and may be inadequate to predict long-term persistence of these species if climate changes occur on the scale predicted.

Our investigation demonstrates that the majority of Hungarian orchids have shifted their yearly mean flowering to earlier dates during the past 50 years. Certain life-history traits, but not phylogenetic relatedness were found to be important in predicting climatic responsiveness in European terrestrial orchids.

We have demonstrated positive non-additive effects in mixtures of leaf litter. The most flammable constituent species of a mixture has disproportionate effects on the fire environment faced by the entire community. This could potentially influence community assembly and alter the selective environment faced by co-occuring species.

This study shows evidence that plant diversity is structured through the interplay between local and landscape processes. Although local conditions constrain species distribution through environmental filtering, plant diversity is not independent from species composition in adjacent habitats. We emphasize the need to account for composition and management of the surrounding landscape matrix to understand the mechanisms that structure and maintain diversity in complex landscapes.

The habitat preferences of liana species in central Panama were compared to tree species with similar abundances. Relative to trees, few lianas showed associations with either topography or soil chemistry. However, most liana species were more abundant than expected in areas of low canopy height suggesting forest disturbance is a driver of observed increases in liana abundance in neotropical forest.

Our results suggest that the 20 species of Psychotria treelets found on Barro Colorado Island, Panama occur in phylogenetically clustered assemblages as a result of environmental filtering of evolutionarily conserved hydraulic traits. We suggest that close relatives are unlikely to exclude one another from shared habitats because resource availability is determined largely by asymmetric competition with the overstorey.

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Most models describing the evolution of dispersal strategies assume that forces selecting for decreased dispersability also select for decreased dispersal distances. However, in Rumex bucephalophorus dispersal distance and dispersability showed contrasting patterns of variation. The fact that these two traits are differently determined could suggest that they can respond in a different manner to selective pressures.

We demonstrate that strong invaders can displace co-occurring native species through multiple mechanisms that are consistent with the functional traits of native species. To our knowledge, this is the first study to relate community-level impacts of an invader to the combined effects of resource exploitation and interference of below-ground mutualisms. Where invaders have the ability to displace early- to late-seral dominants, the consequences for community structure and ecosystem functioning can be profound.

Results advance our understanding of the role of plant traits in ecological communities and reveal that they are important in mediating not only plant-pollinator interactions but also plant-plant interactions. Our findings also shed light on invasive-native plant interactions via pollinators and have the potential to predict certain invasion impacts.

Differences in performance between individuals have important but largely unknown demographic implications. We detected strong and persistent growth differences between individual palms. Population models showed that fast growers contributed twice as much to population growth compared to slow growers. This illustrates the key role of fast growers in plant population dynamics.

Our results highlight the relevance of tree individual characteristics as the main drivers modulating growth responses to climate warming. We conclude that climate warming will have a lower effect on radial growth in slow-growing high elevation trees than in fast-growing low elevation trees, which produce a greater sapwood area. Trees may become relatively insensitive to climate as they age and reach a size-related functional threshold linked to reduced sapwood production.

Experimental chronic defoliation over 3 years, in Chamaedorea elegans palms reduced survival, growth, and reproduction depending on gender. After defoliation stopped, recovery of the vital rates observed over the following 3 years was slower in females than males. This lower resilience may have profound long-lasting consequences for the dynamics and genetic variability of palm populations undergoing prolonged defoliation. Such effects may be aggravated by severe drought episodes caused by El Niño Southern-Oscillation events, which are expected to increase in frequency.

Small canopy gaps are considered ephemeral which would favour the recruitment of late successional species. Spatio-temporal analyses of a sequence of lidar canopy surfaces in high-latitude old-growth boreal forests, on the contrary indicate persistence and pervasiveness of gaps through displacement and expansion. These mechanisms may explain the previously observed maintenance of favourable conditions for the recruitment of shade intolerant individuals.

Gymnadenia conopsea s.l. is a nectar-rewarding, insect-pollinated, terrestrial orchid that avoids shade; it is widely distributed in well-drained calcareous grasslands, and calcareous fens and fen-meadows with short vegetation, but is also occasionally found on heaths. It comprises three recently-recognized segregate species: G. conopsea s.s., G. densiflora and G. borealis, whose individual distributions in the British Isles and ecological properties are still rather poorly known.