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In this short perspective, we discuss some topics to further the decolonisation of ecological research by bringing Global North geographers and Global South ecologists together for the debate. The text reviews current debates and provides reflections on dis/connections between disciplines around decolonisation topics, research publishing, collaboration, and the geographies of ecology. Following recent advances in actions and programs striking the exclusionary effects of English in scientific practice, we argue for increasing efforts on supporting a plurality of expression in science that can strengthen the scientific community beyond the “global North”. Inclusive approaches for collaborative research have been taking steps towards decolonisation, but we highlight these strategies may further unethically practices into targeting determined profiles to satisfy funder requirements without building an inclusive environment. An unequal movement from the “global North” to the “global South” has been the core of unequal collaborations for conserving the nature. Nevertheless, we argue that more effective division of labour could advance field ecology and center in-country ecologists into ecological debate. There is no easy pathway to decolonise ecological research, but we believe that confronting the persisting colonial-era power relationships requires moving into places of necessary discomfort, either by learning new languages or stepping aside. Then, we push this discussion to provoke a moment of introspection and further debate.

International audience; Animal community responses to extreme climate events can be predicted from the functional traits represented within communities. However, it is unclear whether geographic variation in the response of functional community structure to climate change is primarily driven by physiological matching to local conditions (local adaptation hypothesis) or by differences between species pools in functional redundancy (insurance hypothesis). We conducted a coordinated experiment to understand how aquatic invertebrate traits mediate the responses of multitrophic communities to changes in the quantity and evenness of rainfall in 180 natural freshwater microcosms (tank bromeliads) distributed across six sites from 18°N in the Caribbean to 29°S in South America. At each site, we manipulated the mean and dispersion of the daily amount of rainfall that entered tank bromeliads over a 2-month period. Manipulations covered a response surface representing 50% to 200% of the dispersion of daily rainfall crossed with 10% to 300% of the mean amounts of rainfall. The response of functional community structure to precipitation regimes differed across sites. These geographic differences were not consistent with the local adaptation hypothesis, as responses did not correlate with the current amplitude in precipitation. Geographic differences in community responses were consistent with the insurance hypothesis: sites with the lowest functional redundancy in their species pools had the strongest response to a gradient in hydrological variability induced by uneven precipitation. In such sites, an increase in the hydrologic variability induced a shift from communities with both pelagic and benthic traits using both green and brown energy channels to strictly benthic, brown energy communities. Our results predict uneven impacts of precipitation change on community structure and energy channels within communities across Neotropical regions. This geographic variation is due more to differences in the size and redundancy of species pools than to local adaptation. Strategies for climate change adaptation should thus seek to identify and preserve functionally unique species and their habitats. Read the free Plain Language Summary for this article on the Journal blog.

Made available in DSpace on 2020-12-12T01:58:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Consejo Nacional de Investigaciones Científicas y Técnicas Natural Sciences and Engineering Research Council of Canada University of British Columbia Universidad de los Andes Labex Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidad Nacional de Rosario Facultad de Ciencias, Universidad de los Andes Agence Nationale de la Recherche Agencia Nacional de Promoción Científica y Tecnológica Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) There is growing recognition that ecosystems may be more impacted by infrequent extreme climatic events than by changes in mean climatic conditions. This has led to calls for experiments that explore the sensitivity of ecosystems over broad ranges of climatic parameter space. However, because such response surface experiments have so far been limited in geographic and biological scope, it is not clear if differences between studies reflect geographic location or the ecosystem component considered. In this study, we manipulated rainfall entering tank bromeliads in seven sites across the Neotropics, and characterized the response of the aquatic ecosystem in terms of invertebrate functional composition, biological stocks (total invertebrate biomass, bacterial density) and ecosystem fluxes (decomposition, carbon, nitrogen). Of these response types, invertebrate functional composition was the most sensitive, even though, in some sites, the species pool had a high proportion of drought-tolerant families. Total invertebrate biomass was universally insensitive to rainfall change because of statistical averaging of divergent responses between functional groups. The response of invertebrate functional composition to rain differed between geographical locations because (1) the effect of rainfall on bromeliad hydrology differed between sites, and invertebrates directly experience hydrology not rainfall and (2) the taxonomic composition of some functional groups differed between sites, and families differed in their response to bromeliad hydrology. These findings suggest that it will be difficult to establish thresholds of “safe ecosystem functioning” when ecosystem components differ in their sensitivity to climatic variables, and such thresholds may not be broadly applicable over geographic space. In particular, ecological forecast horizons for climate change may be spatially restricted in systems where habitat properties mediate climatic impacts, and those, like the tropics, with high spatial turnover in species composition. Departmetn of Zoology and Biodiversity Research Centre University of British Columbia Ecolab Laboratoire Ecologie Fonctionnelle et Environnement CNRS UPS INPT Université de Toulouse Departamento de Ecologia Instituto de Biologia Centro de Ciências da Saúde Universidade Federal do Rio de Janeiro, Ilha do Fundão Programa de Pós-Graduação em Ecologia Universidade Federal do Rio de Janeiro, Ilha do Fundão Department of Biology University of Puerto Rico Mayaguez Campus AMAP IRD CIRAD CNRS INRA Université Montpellier, CEDEX-5 ECOFOG (AgroParisTech CIRAD CNRS INRA Université de Guyane Université des Antilles) CNRS LMGE (Laboratoire Microorganismes: Génome et Environnement) Université Clermont-Auvergne Laboratory of Multitrophic Interactions and Biodiversity Department of Animal Biology Institute of Biology University of Campinas (UNICAMP) Facultad de Ciencias Agrarias Instituto de Investigaciones en Ciencias Agrarias de Rosario IICAR-CONICET-UNR Universidad Nacional de Rosario Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC)-CNRS UMR 7360 Université de Lorraine, Campus Bridoux INRA Agrocampus-Ouest Ecology and Ecosystem Health, 65 rue de Saint-Brieuc Department of Watershed Sciences and the Ecology Center Utah State University Department of Forest and Conservation Sciences University of British Columbia Department of Zoology and Botany University of São Paulo State (UNESP/IBILCE) Department of Biological Sciences Andes University Departamento de Ciencias Biológicas Universidad de Caldas Department of Zoology and Botany University of São Paulo State (UNESP/IBILCE) FAPESP: # 2016/01209-9 Universidad Nacional de Rosario: 01209-9 Universidad Nacional de Rosario: 04603-4 Universidad Nacional de Rosario: 0877 Universidad Nacional de Rosario: 2012 Facultad de Ciencias, Universidad de los Andes: 2012-1 Universidad Nacional de Rosario: 2012-1 FAPESP: 2012/51143-3 Universidad Nacional de Rosario: 2014 Universidad Nacional de Rosario: 2014-9 FAPESP: 2014/04603-4 Universidad Nacional de Rosario: 2016 Universidad Nacional de Rosario: 400454 Universidad Nacional de Rosario: 51143-3 Agence Nationale de la Recherche: ANR-10-LABX-25-01 Agence Nationale de la Recherche: ANR-12-BSV7-0022-01 Agencia Nacional de Promoción Científica y Tecnológica: PICT-2010-1614 CAPES: PNPD-CAPES 2013/0877 PNPD-CAPES 2014/04603-4

Climate change and biodiversity loss have been reported as major disturbances in the biosphere which can trigger changes in the structure and functioning of natural ecosystems. Nonetheless, empirical studies demonstrating how both factors interact to affect shifts in aquatic ecosystems are still unexplored. Here, we experimentally test how changes in rainfall distribution and litter diversity affect the occurrence of the algae-dominated condition in tank bromeliad ecosystems. Tank bromeliads are miniature aquatic ecosystems shaped by the rainwater and allochthonous detritus accumulated in the bases of their leaves. Here, we demonstrated that changes in the rainfall distribution were able to reduce the chlorophyll-a concentration in the water of bromeliad tanks affecting significantly the occurrence of algae-dominated conditions. On the other hand, litter diversity did not affect the algae dominance irrespective to the rainfall scenario. We suggest that rainfall changes may compromise important self-reinforcing mechanisms responsible for maintaining high levels of algae on tank bromeliads ecosystems. We summarized these results into a theoretical model which suggests that tank bromeliads may show two different regimes, determined by the bromeliad ability in taking up nutrients from the water and by the total amount of light entering the tank. We concluded that predicted climate changes might promote regime shifts in tropical aquatic ecosystems by shaping their structure and the relative importance of other regulating factors.

Phytotelmata in tank-forming Bromeliaceae plants are regarded as potential miniature models for aquatic ecology, but detailed investigations of their microbial communities are rare. Hence, the biogeochemistry in bromeliad tanks remains poorly understood. Here we investigate the structure of bacterial and archaeal communities inhabiting the detritus within the tanks of two bromeliad species, Aechmea nudicaulis and Neoregelia cruenta, from a Brazilian sand dune forest. We used metagenomic sequencing for functional community profiling and 16S sequencing for taxonomic profiling. We estimated the correlation between functional groups and various environmental variables, and compared communities between bromeliad species. In all bromeliads, microbial communities spanned a metabolic network adapted to oxygen-limited conditions, including all denitrification steps, ammonification, sulfate respiration, methanogenesis, reductive acetogenesis and anoxygenic phototrophy. Overall, reducers dominated in abundance over sulfate reducers, and anoxygenic phototrophs largely outnumbered oxygenic photoautotrophs. Functional community structure correlated strongly with environmental variables, between and within a single bromeliad species. Methanogens and reductive acetogens correlated with detrital volume and canopy coverage, and exhibited higher relative abundances in N. cruenta. A comparison of bromeliads to freshwater lake sediments and soil from around the world, revealed stark differences in terms of taxonomic as well as functional microbial community structure. This article is protected by copyright. All rights reserved.

Understanding the processes that are driving variation of natural microbial communities across space or time is a major challenge for ecologists. Environmental conditions strongly shape the metabolic function of microbial communities; however, other processes such as biotic interactions, random demographic drift or dispersal limitation may also influence community dynamics. The relative importance of these processes and their effects on community function remain largely unknown. To address this uncertainty, here we examined bacterial and archaeal communities in replicate 'miniature' aquatic ecosystems contained within the foliage of wild bromeliads. We used marker gene sequencing to infer the taxonomic composition within nine metabolic functional groups, and shotgun environmental DNA sequencing to estimate the relative abundances of these groups. We found that all of the bromeliads exhibited remarkably similar functional community structures, but that the taxonomic composition within individual functional groups was highly variable. Furthermore, using statistical analyses, we found that non-neutral processes, including environmental filtering and potentially biotic interactions, at least partly shaped the composition within functional groups and were more important than spatial dispersal limitation and demographic drift. Hence both the functional structure and taxonomic composition within functional groups of natural microbial communities may be shaped by non-neutral and roughly separate processes.

Climate change will alter the distribution of rainfall, with potential consequences for the hydrological dynamics of aquatic habitats. Hydrological stability can be an important determinant of diversity in temporary aquatic habitats, affecting species persistence and the importance of predation on community dynamics. As such, prey are not only affected by drought-induced mortality but also the risk of predation [a non-consumptive effect (NCE)] and actual consumption by predators [a consumptive effect (CE)]. Climate-induced changes in rainfall may directly, or via altered hydrological stability, affect predator-prey interactions and their cascading effects on the food web, but this has rarely been explored, especially in natural food webs. To address this question, we performed a field experiment using tank bromeliads and their aquatic food web, composed of predatory damselfly larvae, macroinvertebrate prey and bacteria. We manipulated the presence and consumption ability of damselfly larvae under three rainfall scenarios (ambient, few large rainfall events and several small rainfall events), recorded the hydrological dynamics within bromeliads and examined the effects on macroinvertebrate colonization, nutrient cycling and bacterial biomass and turnover. Despite our large perturbations of rainfall, rainfall scenario had no effect on the hydrological dynamics of bromeliads. As a result, macroinvertebrate colonization and nutrient cycling depended on the hydrological stability of bromeliads, with no direct effect of rainfall or predation. In contrast, rainfall scenario determined the direction of the indirect effects of predators on bacteria, driven by both predator CEs and NCEs. These results suggest that rainfall and the hydrological stability of bromeliads had indirect effects on the food web through changes in the CEs and NCEs of predators. We suggest that future studies should consider the importance of the variability in hydrological dynamics among habitats as well as the biological mechanisms underlying the ecological responses to climate change.