ORCID Profile
0000-0002-6499-381X
Current Organisations
University of Waikato
,
German Centre for Integrative Biodiversity Research (iDiv)
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Publisher: Wiley
Date: 14-02-2020
DOI: 10.1002/ECY.2957
Abstract: Deforestation and land-use change in tropical regions result in habitat loss and extinction of species that are unable to adapt to the conditions in agricultural landscapes. If the associated loss of functional ersity is not compensated by species colonizing the converted habitats, extinctions might be followed by a reduction or loss of ecosystem functions including biological control. To date, little is known about how land-use change in the tropics alters the functional ersity of invertebrate predators and which key environmental factors may mitigate the decline in functional ersity and predation in litter and soil communities. We applied litter sieving and heat extraction to study ground spider communities and assessed structural characteristics of vegetation and parameters of litter in rainforest and agricultural land-use systems (jungle rubber, rubber, and oil palm monocultures) in a Southeast Asian hotspot of rainforest conversion: Sumatra, Indonesia. We found that (1) spider density, species richness, functional ersity, and community predation (energy flux to spiders) were reduced by 57-98% from rainforest to oil palm monoculture (2) jungle rubber and rubber monoculture sustained relatively high ersity and predation in ground spiders, but small cryptic spider species strongly declined (3) high species turnover compensated losses of some functional trait combinations, but did not compensate for the overall loss of functional ersity and predation per unit area (4) spider ersity was related to habitat structure such as amount of litter, understory density, and understory height, while spider predation was better explained by plant ersity. Management practices that increase habitat-structural complexity and plant ersity such as mulching, reduced weeding, and intercropping monocultures with other plants may contribute to maintaining functional ersity of and predation services provided by ground invertebrate communities in plantations.
Publisher: Wiley
Date: 13-12-2019
DOI: 10.1111/GCB.14528
Abstract: Concern about human modification of Earth's ecosystems has recently motivated ecologists to address how global change drivers will impact the simultaneous provisioning of multiple functions, termed ecosystem multifunctionality (EMF). However, metrics of EMF have often been applied in global change studies with little consideration of the information they provide beyond single functions, or how and why EMF may respond to global change drivers. Here, we critically review the current state of this rapidly expanding field and provide a conceptual framework to guide the effective incorporation of EMF in global change research. In particular, we emphasize the need for a priori identification and explicit testing of the biotic and abiotic mechanisms through which global change drivers impact EMF, as well as assessing correlations among multiple single functions because these patterns underlie shifts in EMF. While the role of bio ersity in mediating global change effects on EMF has justifiably received much attention, empirical support for effects via other biotic and physicochemical mechanisms are also needed. Studies also frequently stated the importance of measuring EMF responses to global change drivers to understand the potential consequences for multiple ecosystem services, but explicit links between measured functions and ecosystem services were missing from many such studies. While there is clear potential for EMF to provide novel insights to global change research, predictive understanding will be greatly improved by insuring future research is strongly hypothesis-driven, is designed to explicitly test multiple abiotic and biotic mechanisms, and assesses how single functions and their covariation drive emergent EMF responses to global change drivers.
Publisher: Wiley
Date: 04-2020
DOI: 10.1002/BES2.1668
Publisher: Wiley
Date: 02-09-2021
DOI: 10.1111/ELE.13872
Abstract: Animals require a certain amount of habitat to persist and thrive, and habitat loss is one of the most critical drivers of global bio ersity decline. While habitat requirements have been predicted by relationships between species traits and home‐range size, little is known about constraints imposed by environmental conditions and human impacts on a global scale. Our meta‐analysis of 395 vertebrate species shows that global climate gradients in temperature and precipitation exert indirect effects via primary productivity, generally reducing space requirements. Human pressure, however, reduces realised space use due to ensuing limitations in available habitat, particularly for large carnivores. We show that human pressure drives extinction risk by increasing the mismatch between space requirements and availability. We use large‐scale climate gradients to predict current species extinction risk across global regions, which also offers an important tool for predicting future extinction risk due to ongoing space loss and climate change.
Publisher: Springer Science and Business Media LLC
Date: 20-05-2019
DOI: 10.1038/S41559-019-0899-X
Abstract: Predator-prey interactions in natural ecosystems generate complex food webs that have a simple universal body-size architecture where predators are systematically larger than their prey. Food-web theory shows that the highest predator-prey body-mass ratios found in natural food webs may be especially important because they create weak interactions with slow dynamics that stabilize communities against perturbations and maintain ecosystem functioning. Identifying these vital interactions in real communities typically requires arduous identification of interactions in complex food webs. Here, we overcome this obstacle by developing predator-trait models to predict average body-mass ratios based on a database comprising 290 food webs from freshwater, marine and terrestrial ecosystems across all continents. We analysed how species traits constrain body-size architecture by changing the slope of the predator-prey body-mass scaling. Across ecosystems, we found high body-mass ratios for predator groups with specific trait combinations including (1) small vertebrates and (2) large swimming or flying predators. Including the metabolic and movement types of predators increased the accuracy of predicting which species are engaged in high body-mass ratio interactions. We demonstrate that species traits explain striking patterns in the body-size architecture of natural food webs that underpin the stability and functioning of ecosystems, paving the way for community-level management of the most complex natural ecosystems.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-11-2020
Abstract: Increasing plant ersity controls herbivory by limiting energetic gains and enhancing predation of arthropod herbivores.
Location: Germany
No related grants have been discovered for Andrew Barnes.