Ecosystem restoration strengthens pollination network resilience and function.

Land degradation results in declining biodiversity and the disruption of ecosystem functioning worldwide, particularly in the tropics. Vegetation restoration is a common tool used to mitigate these impacts and increasingly aims to restore ecosystem functions rather than species diversity. However, evidence from community experiments on the effect of restoration practices on ecosystem functions is scarce. Pollination is an important ecosystem function and the global decline in pollinators attenuates the resistance of natural areas and agro-environments to disturbances. Thus, the ability of pollination functions to resist or recover from disturbance (that is, the functional resilience) may be critical for ensuring a successful restoration process. Here we report the use of a community field experiment to investigate the effects of vegetation restoration, specifically the removal of exotic shrubs, on pollination. We analyse 64 plant-pollinator networks and the reproductive performance of the ten most abundant plant species across four restored and four unrestored, disturbed mountaintop communities. Ecosystem restoration resulted in a marked increase in pollinator species, visits to flowers and interaction diversity. Interactions in restored networks were more generalized than in unrestored networks, indicating a higher functional redundancy in restored communities. Shifts in interaction patterns had direct and positive effects on pollination, especially on the relative and total fruit production of native plants. Pollinator limitation was prevalent at unrestored sites only, where the proportion of flowers producing fruit increased with pollinator visitation, approaching the higher levels seen in restored plant communities. Our results show that vegetation restoration can improve pollination, suggesting that the degradation of ecosystem functions is at least partially reversible. The degree of recovery may depend on the state of degradation before restoration intervention and the proximity to pollinator source populations in the surrounding landscape. We demonstrate that network structure is a suitable indicator for pollination quality, highlighting the usefulness of interaction networks in environmental management

Old growth mature forest types and their floristic composition along the altitudinal gradient on Silhouette Island (Seychelles) - The telescoping effect on a continental mid-oceanic island

The granitic Seychelles are the only mid-oceanic islands of continental origin. Botanists have long focused on taxonomy, and plant communities were described in a qualitative way, based on simple observation. Therefore the altitudinal belts, their floristic characteristics and distribution are still poorly understood and conservation efforts focus mainly on species-centred actions. Here we describe a quantitative study of plant communities and indicator species differentiated along the altitudinal gradient on Silhouette, the most pristine and second highest (740 m) island of this archipelago. Twelve plots were sampled from 80 m to 640 m above sea level. Each plot contains three nested subplots corresponding to three forest strata: 50 × 10 m for all individuals of the tree layer (i.e. trunk diameter > 5 cm), 50 × 4 m for the shrub layer (ligneous > 90 cm height), and 50 × 4 m for estimation of abundance-dominance coefficient in the herbaceous stratum (all herbaceous plants, plus ligneous plants < 90 cm height). The results are summarized in a two-way table. Both indicator species and vegetation types are discussed in relation to previous studies in Seychelles. Three altitudinal belts are distinguished: lowland, submontane and lower montane rain forests. Most of the best indicator species are found in the understory, especially ferns. The submontane belt develops at about 350 m and turns into a typical lower montane belt at ca. 550 m. Such transition zones occur respectively at about 900 and 1500 m in most of the tropical mountains, illustrating here a perfect example of the "telescoping effect". Although the flora of Seychelles is relatively species poor, the strong characterisation of these altitudinal belts is unusual compared to younger islands in the Pacific, and may be a result of the longer evolution of its flora. © 2009 Gebrüder Borntraeger.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Dryad_RawData_AFinger

Microsatellite and GPS data of adult and seedling individuals

Data from: Forest fragmentation genetics in a formerly widespread island endemic tree: Vateriopsis seychellarum (Dipterocarpaceae)

Habitat fragmentation and changed land use have seriously reduced population size in many tropical forest tree species. Formerly widespread species with limited gene flow may be particularly vulnerable to the negative genetic effects of forest fragmentation and small population size. Vateriopsis seychellarum (Dipterocarpaceae) is a formerly widespread canopy tree of the Seychelles, but is now reduced to 132 adult individuals distributed in eleven sites. Using ten microsatellite loci, a genetic inventory of all adult trees and a sample of 317 progeny, we demonstrate that despite its restricted range, overall genetic diversity was relatively high (HE: 0.56). The juvenile cohort, however, had significantly lower allelic richness (adults RS: 3.91; juveniles RS: 2.83) and observed heterozygosity than adult trees (adults HO: 0.62; juveniles HO: 0.48). Rare alleles were fewer and kinship between individuals was stronger in juveniles. Significant fine-scale spatial genetic structure was observed in remnant adults, and parentage analysis indicated that more than 90% of sampled progeny disperse <25 m and pollen dispersed <50 m. The molecular data confirmed that two populations were derived entirely from self-fertilized offspring from a single surviving mother tree. These populations produce viable offspring. Despite this extreme genetic bottleneck, self-compatibility may provide V. seychellarum with some resistance to the genetic consequences of habitat fragmentation, at least in the short term. We discuss our findings in the context of other rare and threatened dipterocarp species which are vulnerable to mis-management of genetic resources and population fragmentation