Zobel M.,University of Tartu |
Otto R.,University of La Laguna |
Laanisto L.,University of Tartu |
Laanisto L.,CSIC - National Museum of Natural Sciences |
And 4 more authors.
Global Ecology and Biogeography | Year: 2011
Aim Explanations of biogeographic diversity patterns have emphasized the role of large-scale processes that determine species pools, whereas explanations of local patterns have not. We address the hypothesis that local diversity patterns are also primarily dependent on the size of the available species pools, which are expected to be large when the particular habitat type has been evolutionary more abundant, or in unproductive habitats due to shorter generation time and hence higher diversification rates. Location The Canary Islands. Methods We determined the geographic distribution and habitat requirements of all native vascular plant species in the Canary Islands. Species pools for each habitat type on particular islands were further split into two categories according to origin: either originating due to local diversification or due to natural immigration. The dependence of historical diversification and diversification rate on habitat type, area, age, altitude and distance to the mainland was tested with general linear mixed models weighed according to the Akaike information criterion. Results The largest portion of the local variation in plant species diversity was attributed to the historic (pre-human) habitat area, although island age was also important. The diversification rate was higher in unproductive habitats of coastal scrub and summit vegetation. Main conclusion Our study supports the species pool hypothesis, demonstrating that natural local patterns of species diversity in different habitats mirror the abundance of those particular habitats in evolutionary history. It also supports the community-level birth rate hypothesis, claiming that stressful conditions result in higher diversification rates. We conclude that much of the observed local variation in plant diversity can be attributed to the differing sizes of species pools evolved under particular habitat conditions, and that historic parameters are far more important determinants of local diversity than suggested by ecological theory. © 2010 Blackwell Publishing Ltd.
CASTELLANOS-FRIAS E.,CSIC - Institute for Sustainable Agriculture |
GARCIA DE LEON D.,CSIC - Institute for Sustainable Agriculture |
GARCIA DE LEON D.,Laboratorio Internacional en Cambio Global |
BASTIDA F.,University of Huelva |
And 2 more authors.
Journal of Agricultural Science | Year: 2015
Lolium rigidum L. (rigid ryegrass) is one of the most extensive and harmful weeds in winter cereal crops. A bioclimatic model for this species was developed using CLIMEX. The model was validated with records from North America and Oceania and used to assess the global potential distribution of L. rigidum under the current climate and under two climate change scenarios. Both scenarios represent contrasting temporal patterns of economic development and carbon dioxide (CO2) emissions. The projections under current climatic conditions indicated that L. rigidum does not occupy the full extent of the climatically suitable area available to it. Under future climate scenarios, the suitable potential area increases by 3·79% in the low-emission CO2 scenario and by 5·06% under the most extreme scenario. The model's projection showed an increase in potentially suitable areas in North America, Europe, South America and Asia; while in Africa and Oceania it indicated regression. These results provide the necessary knowledge for identifying and highlighting the potential invasion risk areas and for establishing the grounds on which to base the planning and management measures required. Copyright © Cambridge University Press 2015
Troncoso-Palacios J.,University of Chile |
Ferri-Yanez F.,CSIC - National Museum of Natural Sciences |
Ferri-Yanez F.,Laboratorio Internacional en Cambio Global
Check List | Year: 2013
We report two new records for Liolaemus patriciaiturrae in Chile, one corresponding to specimens previously misidentified as L. nigriceps. We also provide a map showing all the known locations of the species. © 2013 Check List and Authors.
Ovando D.A.,University of California at Santa Barbara |
Deacon R.T.,University of California at Santa Barbara |
Lester S.E.,University of California at Santa Barbara |
Costello C.,University of California at Santa Barbara |
And 8 more authors.
Marine Policy | Year: 2013
Cooperatives are increasingly proposed as solutions for sustainable fisheries management. While individual case studies and economic theory suggest that cooperatives may manage fisheries effectively under some conditions, there is little empirical evidence comparing the actions of cooperative fisheries across a diverse set of environments. This study applies a standardized survey method to collect data from a set of cooperatively managed fisheries from around the globe, documenting their social, economic, and ecological settings as well as the cooperative behaviors in which they engage and the role they play in conservation. The resulting database covers 67 cooperatives from the major oceanic regions of the world, providing a unique overview of the global diversity of fishery cooperatives. It enables empirical analysis of the links between the characteristics and contexts of fisheries, such as the development status of the host nation, fisheries management practices, and species characteristics, and the collective actions taken by fishery cooperatives. The evidence shows that cooperatives form in a variety of development and governance contexts, and in diverse kinds of fisheries. Fishery cooperatives often take actions directed toward coordinating harvest activities, adopting and enforcing restrictions on fishing methods and effort, and taking direct conservation actions such as establishment of private marine protected areas. © 2012 Elsevier Ltd.
Tamme R.,University of Tartu |
Hiiesalu I.,University of Tartu |
Laanisto L.,University of Tartu |
Laanisto L.,CSIC - National Museum of Natural Sciences |
And 3 more authors.
Journal of Vegetation Science | Year: 2010
The positive relationship between spatial environmental heterogeneity and species diversity is a widely accepted concept, generally associated with niche limitation. However, niche limitation cannot account for negative heterogeneity-diversity relationships (HDR) revealed in several case studies. Here we explore how HDR varies at different spatial scales and provide novel theories for small-scale species co-existence that explain both positive and negative HDR. At large spatial scales of heterogeneity (e.g. landscape level), different communities co-exist, promoting large regional species pool size and resulting in positive HDR. At smaller scales within communities, species co-existence can be enhanced by increasing the number of different patches, as predicted by the niche limitation theory, or alternatively, restrained by heterogeneity. We conducted meta-regressions for experimental and observational HDR studies, and found that negative HDRs are significantly more common at smaller spatial scales. We propose three theories to account for niche limitation at small spatial scales. (1) Microfragmentation theory: with increasing spatial heterogeneity, large homogeneous patches lose area and become isolated, which in turn restrains the establishment of new plant individuals and populations, thus reducing species richness. (2) Heterogeneity confounded by mean: when heterogeneity occurs at spatial scales smaller than the size of individual plants, which forage through the patches, species diversity can be either positively or negatively affected by a change in the mean of an environmental factor. (3) Heterogeneity as a separate niche axis: the ability of species to tolerate heterogeneity at spatial scales smaller than plant size varies, affecting HDR. We conclude that processes other than niche limitation can affect the relationship between heterogeneity and diversity. © 2010 International Association for Vegetation Science.
Duarte C.M.,University of Western Australia |
Fulweiler R.W.,Boston University |
Lovelock C.E.,University of Queensland |
Martinetto P.,Institute Investigaciones Marinas y Costeras |
And 6 more authors.
BioScience | Year: 2015
The proliferation of a number of pressures affecting the ocean is leading to a growing concern that the state of the ocean is compromised, which is driving society into pessimism. Ocean calamities are disruptive changes to ocean ecosystems that have profound impacts and that are widespread or global in scope. However, scrutiny of ocean calamities to ensure that they can be confidently attributed to human drivers, operate at widespread or global scales, and cause severe disruptions of marine social-ecosystems shows that some of the problems fail to meet these requirements or that the evidence is equivocal. A number of biases internal and external to the scientific community contribute to perpetuating the perception of ocean calamities in the absence of robust evidence. An organized auditing of ocean calamities may deliver a more precise diagnosis of the status of the oceans, which may help to identify the most pressing problems that need be addressed to conserve a healthy ocean. © 2014 The Author(s).
Pires A.P.F.,Federal University of Rio de Janeiro |
Marino N.A.C.,Federal University of Rio de Janeiro |
Srivastava D.S.,University of British Columbia |
Farjalla V.F.,Federal University of Rio de Janeiro |
Farjalla V.F.,Laboratorio Internacional en Cambio Global
Ecology | Year: 2016
Changes in the distribution of rainfall and the occurrence of extreme rain events will alter the size and persistence of aquatic ecosystems. Such alterations may affect the structure of local aquatic communities in terms of species composition, and by altering species interactions. In many aquatic ecosystems, leaf litter sustains detrital food webs and could regulate the responses of communities to changes in rainfall. Few empirical studies have focused on how rainfall changes will affect aquatic communities and none have evaluated if basal resource diversity can increase resistance to such rainfall effects. In this study, we used water-holding terrestrial bromeliads, a tropical aquatic ecosystem, to test how predicted rainfall changes and litter diversity may affect community composition and trophic interactions. We used structural equation modeling to investigate the combined effects of rainfall changes and litter diversity on trophic interactions. We demonstrated that changes in rainfall disrupted trophic relationships, even though there were only minor direct effects on species abundance, richness, and community composition. Litter diversity was not able to reduce the impact of changes in rainfall on trophic interactions. We suggest that changes in rainfall can alter the way in which species interact with each other, decreasing the linkages among trophic groups. Such reductions in biotic interactions under climate change will have critical consequences for the functioning of tropical aquatic ecosystems. © 2016 by the Ecological Society of America.
Aiken C.M.,University of Santiago de Chile |
Aiken C.M.,Laboratorio Internacional en Cambio Global |
Navarrete S.A.,University of Santiago de Chile |
Navarrete S.A.,Laboratorio Internacional en Cambio Global |
And 2 more authors.
Journal of Geophysical Research: Biogeosciences | Year: 2011
Climate change is likely to result in significant alterations in the atmospheric and oceanic circulation, which may, as a result, affect species that depend on an ocean-driven nutrient supply and particularly those that possess a dispersal phase in their life history. In this paper we investigate the potential changes in larval dispersal and connectivity of marine populations on the Chilean coast due to altered wind forcing consistent with a future climate change scenario. Numerical ocean simulations forced by modeled present-day and future winds under the Intergovernmental Panel on Climate Change A2 scenario are used to investigate the potential changes in nearshore circulation. Off-line particle-tracking simulations are then analyzed to determine resulting changes in larval dispersal and connectivity under each scenario as a function of pelagic larval duration and for two different possible larval behaviors: passive and vertical migration. It is found that the projected future winds drive an intensification of the upwelling circulation, which results in a relative annual mean surface cooling of 1°C over much of the domain, an increase in the strength of the poleward undercurrent, and a more energetic mesoscale eddy field. Neutrally buoyant larvae are inferred to have low rates of settlement under present conditions and are more strongly disadvantaged under the simulated future conditions than larvae with vertically migrating behavior. Larvae that posses an ability to sink out of the surface Ekman layer are found to have higher rates of settlement under present conditions and are, in fact, favored slightly in the A2 scenario for pelagic larval durations longer than 2 days. This behavior-dependent response to future conditions may potentially drive a reorganization of coastal communities. Copyright 2011 by the American Geophysical Union.
Wood C.L.,Stanford University |
Micheli F.,Stanford University |
Fernandez M.,University of Santiago de Chile |
Gelcich S.,University of Santiago de Chile |
And 3 more authors.
Journal of Animal Ecology | Year: 2013
Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. We found that nearly all parasite species exhibited substantially greater density (# parasites m-2) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.