1. |
- Rist, Lucy, et al.
(författare)
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Sustainable harvesting of coco de mer, Lodoicea maldivica, in the Vallée de Mai, Seychelles
- 2010
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 260:12, s. 2224-2231
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Tidskriftsartikel (refereegranskat)abstract
- The coco de mer palm Lodoicea maldivica, endemic to the Seychelles, is a flagship species for tourism and conservation. It bears the world's largest seed for which it is currently heavily exploited across its limited range, and it is clear that harvesting at current levels cannot be maintained indefinitely. Biologically informed harvesting protocols are therefore required to move towards sustainable management that secures the long-term viability of the population and the revenue that it currently generates. Demographic modelling using population matrix models is a useful tool in these efforts as it identifies both the life stages with the strongest influence on population dynamics as well as the consequences of current use intensities. Here we provide an initial population model based on data currently available to assess the status of the largest L. maldivica population in the Vallée de Mai World Heritage Site. We estimated transition probabilities and constructed matrices to estimate the populations’ growth rate under current and alternative harvesting regimes, taking into account uncertainty regarding adult mortality and lifespan. Model projections of the population under current harvesting intensities forecast a marked decrease in the proportion of juveniles in the population and a gradually declining population over the next 200 years. Population growth rates were most sensitive to adult survival, reflecting the long generation time of this species and the remaining uncertainty in this respect. Based on this preliminary model we propose a precautionary sustainable harvesting limit for L. maldivica and discuss the challenges and opportunities of its management, including recommendations for future data collection.
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2. |
- Schleuning, Matthias, et al.
(författare)
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Specialization of Mutualistic Interaction Networks Decreases toward Tropical Latitudes
- 2012
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Ingår i: Current Biology. - : Elsevier BV. - 1879-0445 .- 0960-9822. ; 22:20, s. 1925-1931
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Tidskriftsartikel (refereegranskat)abstract
- Species-rich tropical communities are expected to be more specialized than their temperate counterparts [1-3]. Several studies have reported increasing biotic specialization toward the tropics [4-7], whereas others have not found latitudinal trends once accounting for sampling bias [8, 9] or differences in plant diversity [10, 11]. Thus, the direction of the latitudinal Specialization gradient remains contentious. With an unprecedented global data set, we investigated how biotic specialization between plants and animal pollinators or seed dispersers is associated with latitude, past and contemporary climate, and plant diversity. We show that in contrast to expectation, biotic specialization of mutualistic networks is significantly lower at tropical than at temperate latitudes. Specialization was more closely related to contemporary climate than to past climate stability, suggesting that current conditions have a stronger effect on biotic specialization than historical community stability. Biotic specialization decreased with increasing local and regional plant diversity. This suggests that high specialization of mutualistic interactions is a response of pollinators and seed dispersers to low plant diversity. This could explain why the latitudinal specialization gradient is reversed relative to the latitudinal diversity gradient. Low mutualistic network specialization in the tropics suggests higher tolerance against extinctions in tropical than in temperate communities.
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3. |
- Thurstan, Ruth H., et al.
(författare)
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Envisioning a resilient future for biodiversity conservation in the wake of the COVID-19 pandemic
- 2021
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Ingår i: People and Nature. - : Wiley. - 2575-8314. ; 3:5, s. 990-1013
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Forskningsöversikt (refereegranskat)abstract
- As the COVID-19 pandemic continues to affect societies across the world, the ongoing economic and social disruptions are likely to present fundamental challenges for current and future biodiversity conservation. We review the literature for outcomes of past major societal, political, economic and zoonotic perturbations on biodiversity conservation, and demonstrate the complex implications of perturbation events upon conservation efforts. Building on the review findings, we use six in-depth case studies and the emerging literature to identify positive and negative outcomes of the COVID-19 pandemic, known and anticipated, for biodiversity conservation efforts around the world. A number of similarities exist between the current pandemic and past perturbations, with experiences highlighting that the pandemic-induced declines in conservation revenue and capacity, livelihood and trade disruptions are likely to have long-lasting and negative implications for biodiversity and conservation efforts. Yet, the COVID-19 pandemic also brought about a global pause in human movement that is unique in recent history, and may yet foster long-lasting behavioural and societal changes, presenting opportunities to strengthen and advance conservation efforts in the wake of the pandemic. Enhanced collaborations and partnerships at the local level, cross-sectoral engagement, local investment and leadership will all enhance the resilience of conservation efforts in the face of future perturbations. Other actions aimed at enhancing resilience will require fundamental institutional change and extensive government and public engagement and support if they are to be realised. The pandemic has highlighted the inherent vulnerabilities in the social and economic models upon which many conservation efforts are based. In so doing, it presents an opportunity to reconsider the status quo for conservation, and promotes behaviours and actions that are resilient to future perturbation. A free Plain Language Summary can be found within the Supporting Information of this article.
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4. |
- Carvalheiro, Luisa Gigante, et al.
(författare)
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The potential for indirect effects between co-flowering plants via shared pollinators depends on resource abundance, accessibility and relatedness
- 2014
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 17:11, s. 1389-1399
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Tidskriftsartikel (refereegranskat)abstract
- Co-flowering plant species commonly share flower visitors, and thus have the potential to influence each other's pollination. In this study we analysed 750 quantitative plant-pollinator networks from 28 studies representing diverse biomes worldwide. We show that the potential for one plant species to influence another indirectly via shared pollinators was greater for plants whose resources were more abundant (higher floral unit number and nectar sugar content) and more accessible. The potential indirect influence was also stronger between phylogenetically closer plant species and was independent of plant geographic origin (native vs. non-native). The positive effect of nectar sugar content and phylogenetic proximity was much more accentuated for bees than for other groups. Consequently, the impact of these factors depends on the pollination mode of plants, e.g. bee or fly pollinated. Our findings may help predict which plant species have the greatest importance in the functioning of plant-pollination networks.
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