Resilience and adaptability of rice terrace social-ecological systems: A case study of a local community’s perception in Banaue, Philippines

© 2016 by the author(s). The social-ecological systems of rice terraces across Southeast Asia are the result of centuries of long-term interactions between human communities and their surrounding ecosystems. Processes and structures in these systems have evolved to provide a diversity of ecosystem services and benefits to human societies. However, as Southeast Asian countries experience rapid economic growth and related land-use changes, the remaining extensive rice cultivation systems are increasingly under pressure. We investigated the long-term development of ecosystem services and the adaptive capacity of the social-ecological system of rice terrace landscapes using a case study of Banaue (Ifugao Province, Northern-Luzon, Philippines). A set of indicators was used to describe and assess changes in the social-ecological state of the study system. The resilience of the rice terraces and the human communities that maintain them was examined by comparing the current state of the system with results from the literature. Our findings indicate that, although the social-ecological system has not yet shifted to an alternative state, pressures are increasing and some cultural ecosystem services have already been lost

Regional-scale effects override the influence of fine-scale landscape heterogeneity on rice arthropod communities

© 2017 The Authors Irrigated rice croplands are among the most biologically diverse agroecosystems globally; however, intensification and simplification of farmed areas into homogeneous monocultures can lead to biodiversity loss and a reduction of associated ecosystem services such as natural pest regulation. Understanding how landscape heterogeneity affects the diversity of arthropod communities is therefore crucial for the sustainable management of rice agroecosystems. Here, we examine the influence of fine-scale landscape heterogeneity and regional-scale effects on the arthropod communities of three rice-production regions in the Philippines. Our analysis of 213 arthropod morphospecies (37,339 individuals) collected using two sampling methods at 28 field sites indicated that the rice agroecosystems in each study region had unique arthropod assemblages, likely reflecting region-specific environmental and land-use conditions. For all sites together, we found no effect of fine-scale landscape context (classified as rather high or low heterogeneity sites) on assemblage structure (arthropod abundance, species richness or diversity). When assemblages were analyzed separately, significant effects of fine-scale landscape context were only detected in one region and for two functional groups (predators and detritivores). Elevation gradient, used as a proxy for regional-scale effects in the study regions, explained more than 60% of variance in assemblage structure. Total arthropod abundance and rarefied species richness were negatively related to elevation, suggesting that regional-scale effects rather than fine-scale landscape heterogeneity explained the composition of rice-arthropod communities in landscapes. To further disentangle the complex effects of broad-scale environmental drivers versus fine-scale landscape complexity on arthropod communities and biocontrol services, future research in rice agroecosystems should focus on a more detailed quantification of landscape heterogeneity and examine its effect at multiple spatial scales

Inaugural BMC Ecology and Evolution image competition: the winning images

The inaugural BMC Ecology and Evolution image competition attracted entries from talented ecologists and evolutionary biologists worldwide. Together, these photos beautifully capture biodiversity, how it arose and why we should conserve it. This editorial celebrates the winning images as selected by the Editor of BMC Ecology and Evolution and senior members of the journal’s editorial board

Evaluating the ecological realism of plant species distribution models with ecological indicator values

Species distribution models (SDMs) are routinely applied to assess current as well as future species distributions, for example to assess impacts of future environmental change on biodiversity or to underpin conservation planning. It has been repeatedly emphasized that SDMs should be evaluated based not only on their goodness of fit to the data, but also on the realism of the modelled ecological responses. However, possibilities for the latter are hampered by limited knowledge on the true responses as well as a lack of quantitative evaluation methods. Here we compared modelled niche optima obtained from European-scale SDMs of 1,476 terrestrial vascular plant species with empirical ecological indicator values indicating the preferences of plant species for key environmental conditions. For each plant species we first fitted an ensemble SDM including three modeling techniques (GLM, GAM and BRT) and extracted niche optima for climate, soil, land use and nitrogen deposition variables with a large explanatory power for the occurrence of that species. We then compared these SDM-derived niche optima with the ecological indicator values by means of bivariate correlation analysis. We found weak to moderate correlations in the expected direction between the SDM-derived niche optima and ecological indicator values. The strongest correlation occurred between the modelled optima for growing degree days and the ecological indicator values for temperature. Correlations were weaker for SDM-derived niche optima with a more distal relationship to ecological indicator values (notably precipitation and soil moisture). Further, correlations were consistently highest for BRT, followed by GLM and GAM. Our method gives insight into the ecological realism of modelled niche optima and projected core habitats and can be used to improve SDMs by making a more informed selection of environmental variables and modeling techniques

Development of parasitic Maculinea teleius (Lepidoptera, Lycaenidae) larvae in laboratory nests of four Myrmica ant host species

Maculinea butterflies are social parasites of Myrmica ants. Methods to study the strength of host ant specificity in the Maculinea–Myrmica association include research on chemical and acoustic mimicry as well as experiments on ant adoption and rearing behaviour of Maculinea larvae. Here we present results of laboratory experiments on adoption, survival, development and integration of M. teleius larvae within the nests of different Myrmica host species, with the objective of quantifying the degree of specialization of this Maculinea species. In the laboratory, a total of 94 nests of four Myrmica species: M. scabrinodis, M. rubra, M.ruginodis and M. rugulosa were used. Nests of M. rubra and M. rugulosa adopted M. teleius larvae more readily and quickly than M. ruginodis colonies. No significant differences were found in the survival rates of M. teleius larvae reared by different ant species. Early larval growth of M. teleius larvae differed slightly among nests of four Myrmica host species. Larvae reared by colonies of M. rugulosa which were the heaviest at the beginning of larval development had the lowest mean larval body mass after 18 weeks compared to those reared by other Myrmica species. None of the M.teleius larvae was carried by M. scabrinodis or M. rubra workers after ant nests were destroyed, which suggests a lack of integration with host colonies. Results indicate that Myrmica species coming from the same site differ in their ability to adopt and rear M. teleius larvae but there was no obvious adaptation of this butterfly species to one of the host ant species. This may explain why, under natural conditions, all four ants can be used as hosts of this butterfly species. Slight advantages of particular Myrmica species as hosts at certain points in butterfly larval development can be explained by the ant species biology and colony structure rather than by specialization of M. teleius

The social parasite Phengaris (Maculinea) nausithous affects genetic diversity within Myrmica rubra host ant colonies

Evolutionary theory predicts that high genetic variation maintains plasticity in a species’ response to parasite pressure. However, higher genetic diversity might also cause easier infiltration by social parasites, because odour diversity is high and nest-mate recognition poor. Here we test if the obligate myrmecophile Lycaenid butterfly Phengaris nausithous, a parasite of colonies of the highly polygynous ant Myrmica rubra causes local adaptation by enhancing genetic variance in parasitized versus non parasitized ant populations M. rubra colonies from six infested and three uninfested sites were assayed at five microsatellite loci to quantify genetic variation. Our results reveal isolation by distance and a significantly enhanced intracolonial variance due to the parasite pressure.HIGRADE scholarship. CLIMIT project.http://link.springer.com/journal/10841hb201

Identifying and prioritising services in European terrestrial and freshwater ecosystems

Ecosystems are multifunctional and provide humanity with a broad array of vital services. Effective management of services requires an improved evidence base, identifying the role of ecosystems in delivering multiple services, which can assist policy-makers in maintaining them. Here, information from the literature and scientific experts was used to systematically document the importance of services and identify trends in their use and status over time for the main terrestrial and freshwater ecosystems in Europe. The results from this review show that intensively managed ecosystems contribute mostly to vital provisioning services (e.g. agro-ecosystems provide food via crops and livestock, and forests provide wood), while semi-natural ecosystems (e.g. grasslands and mountains) are key contributors of genetic resources and cultural services (e.g. aesthetic values and sense of place). The most recent European trends in human use of services show increases in demand for crops from agro-ecosystems, timber from forests, water flow regulation from rivers, wetlands and mountains, and recreation and ecotourism in most ecosystems, but decreases in livestock production, freshwater capture fisheries, wild foods and virtually all services associated with ecosystems which have considerably decreased in area (e.g. semi-natural grasslands). The condition of the majority of services show either a degraded or mixed status across Europe with the exception of recent enhancements in timber production in forests and mountains, freshwater provision, water/erosion/natural hazard regulation and recreation/ecotourism in mountains, and climate regulation in forests. Key gaps in knowledge were evident for certain services across all ecosystems, including the provision of biochemicals and natural medicines, genetic resources and the regulating services of seed dispersal, pest/disease regulation and invasion resistance

Is subarctic forest advance able to keep pace with climate change?

Recent climate warming and scenarios for further warming have led to expectations of rapid movement of ecological boundaries. Here we focus on the circumarctic forest-tundra ecotone (FTE), which represents an important bioclimatic zone with feedbacks from forest advance and corresponding tundra disappearance (up to 50% loss predicted this century) driving widespread ecological and climatic changes. We address FTE advance and climate history relations over the 20th century, using FTE response data from 151 sites across the circumarctic area and site-specific climate data. Specifically, we investigate spatial uniformity of FTE advance, statistical associations with 20th century climate trends, and whether advance rates match climate change velocities (CCVs). Study sites diverged into four regions (Eastern Canada; Central and Western Canada and Alaska; Siberia; and Western Eurasia) based on their climate history, although all were characterized by similar qualitative patterns of behaviour (with about half of the sites showing advancing behaviour). The main associations between climate trend variables and behaviour indicate the importance of precipitation rather than temperature for both qualitative and quantitative behaviours, and the importance of non-growing season as well as growing season months. Poleward latitudinal advance rates differed significantly among regions, being smallest in Eastern Canada (~10 m/year) and largest in Western Eurasia (~100 m/year). These rates were 1-2 orders of magnitude smaller than expected if vegetation distribution remained in equilibrium with climate. The many biotic and abiotic factors influencing FTE behaviour make poleward advance rates matching predicted 21st century CCVs (~103 -104  m/year) unlikely. The lack of empirical evidence for swift forest relocation and the discrepancy between CCV and FTE response contradict equilibrium model-based assumptions and warrant caution when assessing global-change-related biotic and abiotic implications, including land-atmosphere feedbacks and carbon sequestration.Funding was provided by the Norwegian Research Council (grants 176065/S30, 185023/S50, 160022/F40 and 244557/RI), the Government of Canada Program for International Polar Year, the US National Science Foundation, and the University of Cambridge