| 1. |
- Cavieres, Lohengrin A., et al.
(författare)
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Facilitative plant interactions and climate simultaneously drive alpine plant diversity
- 2014
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Ingår i: Ecology Letters. - : Wiley. - 1461-0248 .- 1461-023X. ; 17:2, s. 193-202
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Tidskriftsartikel (refereegranskat)abstract
- Interactions among species determine local-scale diversity, but local interactions are thought to have minor effects at larger scales. However, quantitative comparisons of the importance of biotic interactions relative to other drivers are rarely made at larger scales. Using a data set spanning 78 sites and five continents, we assessed the relative importance of biotic interactions and climate in determining plant diversity in alpine ecosystems dominated by nurse-plant cushion species. Climate variables related with water balance showed the highest correlation with richness at the global scale. Strikingly, although the effect of cushion species on diversity was lower than that of climate, its contribution was still substantial. In particular, cushion species enhanced species richness more in systems with inherently impoverished local diversity. Nurse species appear to act as a ‘safety net’ sustaining diversity under harsh conditions, demonstrating that climate and species interactions should be integrated when predicting future biodiversity effects of climate change.
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| 2. |
- Goncalves-Pereira, M, et al.
(författare)
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[Needs for Care and Service Use in Dementia: Baseline Assessment of Portuguese Participants in the Actifcare Cohort Study]
- 2019
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Ingår i: Acta medica portuguesa. - : Ordem dos Medicos. - 1646-0758 .- 0870-399X. ; 32:5, s. 355-367
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Tidskriftsartikel (refereegranskat)abstract
- Introdução: As pessoas com demência e os seus familiares deveriam ter acesso atempado a cuidados formais na comunidade (centros de dia, apoio domiciliário). O projecto EU-Actifcare investigou o acesso/utilização destes serviços em países europeus. Descrevemos a implementação do estudo de coorte e a avaliação inicial em Portugal, com foco nas necessidades de cuidados e recurso aos serviços.Material e Métodos: Selecionámos uma amostra de conveniência de 66 pessoas com diagnóstico de demência ligeira a moderada (residindo na comunidade sem cuidados formais relevantes) e respetivos familiares-cuidadores. A avaliação (clínico-funcional e social) incluiu os instrumentos Camberwell Assessment of Need for the Elderly e Resource Utilization in Dementia.Resultados: Identificámos necessidades não-cobertas dos doentes (média 1,1; DP = 1,7), principalmente de companhia (23% dos casos), sofrimento psicológico (20%) e atividades diárias (14%). Os familiares-cuidadores dedicavam 150 minutos/dia (mediana) à prestação de cuidados e 44% apresentavam necessidades não-cobertas de sofrimento psicológico. Quando havia problemas de acesso/utilização dos serviços de saúde e sociais na comunidade, estes estavam frequentemente relacionados com recusa ou desconhecimento de utentes/familiares.Discussão: A seleção dos participantes não foi fácil, pela especificidade dos critérios adotados. Não almejando representatividade nacional, recrutámos uma amostra típica de pessoas em estádios ligeiros a moderados de demência, em serviços e regiões diferentes. Nalguns casos, encontrámos necessidades não-cobertas e repercussões familiares que já justificariam respostas de serviços na comunidade, não fossem os problemas de acesso/utilização.Conclusão: Na área das demências, existem dificuldades no acesso atempado e utilização efectiva de cuidados formais, coexistindo com uma cobertura menor de necessidades específicas.
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| 3. |
- Brooker, R.W., et al.
(författare)
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Facilitation in plant communities: the past, the present, and the future
- 2008
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 96:1, s. 18-34
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Tidskriftsartikel (refereegranskat)abstract
- 1. Once neglected, the role of facilitative interactions in plant communities has received considerable attention in the last two decades, and is now widely recognized. It is timely to consider the progress made by research in this field.2. We review the development of plant facilitation research, focusing on the history of the field, the relationship between plant–plant interactions and environmental severity gradients, and attempts to integrate facilitation into mainstream ecological theory. We then consider future directions for facilitation research.3. With respect to our fundamental understanding of plant facilitation, clarification of the relationship between interactions and environmental gradients is central for further progress, and necessitates the design and implementation of experiments that move beyond the clear limitations of previous studies.4. There is substantial scope for exploring indirect facilitative effects in plant communities, including their impacts on diversity and evolution, and future studies should connect the degree of non-transitivity in plant competitive networks to community diversity and facilitative promotion of species coexistence, and explore how the role of indirect facilitation varies with environmental severity.5. Certain ecological modelling approaches (e.g. individual-based modelling), although thus far largely neglected, provide highly useful tools for exploring these fundamental processes.6. Evolutionary responses might result from facilitative interactions, and consideration of facilitation might lead to re-assessment of the evolution of plant growth forms.7. Improved understanding of facilitation processes has direct relevance for the development of tools for ecosystem restoration, and for improving our understanding of the response of plant species and communities to environmental change drivers.8. Attempts to apply our developing ecological knowledge would benefit from explicit recognition of the potential role of facilitative plant–plant interactions in the design and interpretation of studies from the fields of restoration and global change ecology.9. Synthesis: Plant facilitation research provides new insights into classic ecological theory and pressing environmental issues. Awareness and understanding of facilitation should be part of the basic ecological knowledge of all plant ecologists.
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| 4. |
- Kikvidze, Zaal, et al.
(författare)
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The effects of foundation species on community assembly: a global study on alpine cushion plant communities
- 2015
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Ingår i: Ecology. - : Ecological Society of America. - 0012-9658. ; 96:8, s. 2064-2069
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Tidskriftsartikel (refereegranskat)abstract
- Foundation species can change plant community structure by modulating important ecological processes such as community assembly, yet this topic is poorly understood. In alpine systems, cushion plants commonly act as foundation species by ameliorating local conditions. Here, we analyze diversity patterns of species' assembly within cushions and in adjacent surrounding open substrates (83 sites across five continents) calculating floristic dissimilarity between replicate plots, and using linear models to analyze relationships between microhabitats and species diversity. Floristic dissimilarity did not change across biogeographic regions, but was consistently lower in the cushions than in the open microhabitat. Cushion plants appear to enable recruitment of many relatively stress-intolerant species that otherwise would not establish in these communities, yet the niche space constructed by cushion plants supports a more homogeneous composition of species than the niche space beyond the cushion's influence. As a result, cushion plants support higher α-diversity and a larger species pool, but harbor assemblies with lower ?-diversity than open microhabitats. We conclude that habitats with and without dominant foundation species can strongly differ in the processes that drive species recruitment, and thus the relationship between local and regional species diversity.
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| 5. |
- Butterfield, B. J., et al.
(författare)
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Alpine cushion plants inhibit the loss of phylogenetic diversity in severe environments
- 2013
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Ingår i: Ecology Letters. - : Wiley. - 1461-0248 .- 1461-023X. ; 16:4, s. 478-486
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Tidskriftsartikel (refereegranskat)abstract
- Biotic interactions can shape phylogenetic community structure (PCS). However, we do not know how the asymmetric effects of foundation species on communities extend to effects on PCS. We assessed PCS of alpine plant communities around the world, both within cushion plant foundation species and adjacent open ground, and compared the effects of foundation species and climate on alpha (within-microsite), beta (between open and cushion) and gamma (open and cushion combined) PCS. In the open, alpha PCS shifted from highly related to distantly related with increasing potential productivity. However, we found no relationship between gamma PCS and climate, due to divergence in phylogenetic composition between cushion and open sub-communities in severe environments, as demonstrated by increasing phylo-beta diversity. Thus, foundation species functioned as micro-refugia by facilitating less stress-tolerant lineages in severe environments, erasing a global productivity – phylogenetic diversity relationship that would go undetected without accounting for this important biotic interaction.
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