Find research datasets worth reusing

Data from: Higher species richness enhances yield stability in intensively managed grasslands with experimental disturbance

Climate models predict increased frequency and severity of drought events. At an Irish and Swiss site, experimental summer droughts were applied over two successive years to grassland plots sown with one, two or four grassland species with contrasting functional traits. Mean yield and plot-to-plot variance of yield were measured across harvests during drought and after a subsequent post-drought recovery period. At both sites, there was a positive relationship between species richness and yield. Under rainfed control conditions, mean yields of four-species communities were 32% (Wexford, Ireland) and 51% (Zürich, Switzerland) higher than in monocultures. This positive relationship was also evident under drought, despite significant average yield reductions (-27% at Wexford; -21% at Zürich). Four-species communities had lower plot-to-plot variance of yield compared to monoculture or two-species communities under both rainfed and drought conditions, which demonstrates higher yield stability in four-species communities. At the Swiss but not the Irish site, a high degree of species asynchrony could be identified as a mechanism underlying increased temporal stability in four-species communities. These results indicate the high potential of multi-species grasslands as an adaptation strategy against drought events and help achieve sustainable intensification under both unperturbed and perturbed environmental conditions.

Data from: Identifying native plants for coordinated habitat management of arthropod pollinators, herbivores and natural enemies

1. Providing non-crop flowering resources in agricultural landscapes is widely promoted as a strategy to support arthropods that deliver pollination and pest control services. However, management options have largely been developed separately for pollinators and natural enemies, whereas possible effects on insect herbivores, such as crop pests, have often been overlooked. A first critical step for design and implementation of multifunctional plantings that promote beneficial arthropods while controlling insect pests is to identify suitable plant species to use. 2. We aimed to identify California native plants and, more generally, plant traits suitable for the coordinated management of pollinators (wild bees and honey bees), insect herbivores and arthropod natural enemies (predators and parasitic wasps). We established 43 plant species in a common garden experiment and sampled arthropods by weekly netting (wild bees), observations (honey bees) or vacuum sampling (insect herbivores, arthropod predators and parasitic wasps) during peak bloom of each plant species over two years. 3. Plant species differed in attractiveness for each arthropod functional group. Floral area of the focal plant species positively affected honey bee, predator and parasitic wasp attractiveness. Later bloom period was associated with lower numbers of parasitic wasps. Flower type (actinomorphic, composite or zygomorphic) predicted attractiveness for honey bees, which preferred actinomorphic over composite flowers and for parasitic wasps, which preferred composite flowers over actinomorphic flowers. 4. Across plant species, herbivore, predator and parasitic wasp abundances were positively correlated, and honey bee abundance correlated negatively to herbivore abundance. 5. Synthesis and applications. We use data from our common garden experiment to inform evidence-based selection of plants that support pollinators and natural enemies without enhancing potential pests. We recommend selecting plant species with a high floral area per ground area unit, as this metric predicts the abundances of several groups of beneficial arthropods. Multiple correlations between functionally important arthropod groups across plant species stress the importance of a multifunctional approach to arthropod habitat management.

Data from: Distinguishing the victim from the threat: SNP‐based methods reveal the extent of introgressive hybridization between wildcats and domestic cats in Scotland and inform future in situ and ex situ management options for species restoration

The degree of introgressive hybridisation between the Scottish wildcat and domestic cat has long been suspected to be advanced. Here we use a 35-SNP-marker test, designed to assess hybridisation between wildcat and domestic cat populations in Scotland, to assess a database of 265 wild-living and captive cat samples, and test the assumptions of the test using 3097 SNP markers generated independently in a subset of the data using ddRAD. We discovered that despite increased genetic resolution provided by these methods, wild-living cats in Scotland show a complete genetic continuum or hybrid swarm structure when judged against reference data. The historical population of wildcats, although hybridised, clearly groups at one end of this continuum, as does the captive population of wildcats. The interpretation of pelage scores against nuclear genetic data continues to be problematic. This is probably because of a breakdown in linkage disequilibrium between wildcat pelage genes as the two populations have become increasingly mixed, meaning that pelage score or SNP score alone are poor diagnostic predictors of hybrid status. Until better tools become available, both should be used jointly, where possible, when making management decisions about individual cats. We recommend that the conservation community in Scotland must now define clearly what measures are to be used to diagnose a wildcat in the wild in Scotland, if future conservation action is to be effective.

Data from: Challenges of NGS in conservation management: insights from long-term monitoring of corridor effects on the genetic diversity of mouse lemurs in a fragmented landscape

Long-term genetic monitoring of populations is essential for efforts aimed at preserving genetic diversity of endangered species. Here, we employ a framework of long-term genetic monitoring to evaluate the effects of fragmentation and the effectiveness of the establishment of corridors in restoring population connectivity and genetic diversity of mouse lemurs Micocebus ganzhorni. To this end, we supplement estimates of neutral genetic diversity with the assessment of adaptive genetic variability of the MHC. In addition, we address the challenges of long-term genetic monitoring of functional diversity by comparing the genotyping performance and estimates of MHC variability generated by SSCP/Sanger-sequencing with those obtained by high throughput sequencing (NGS, Illumina), an issue that is particularly relevant when previous work serves as a baseline for planning management strategies that aim to ensure the viability of a population. We report that SSCP greatly underestimates individual diversity and that discrepancies in estimates of MHC diversity attributable to the comparisons of traditional and NGS genotyping techniques can influence the conclusions drawn from conservation management scenarios. Evidence of migration among fragments in Mandena suggests that mouse lemurs are robust to the process of fragmentation and that the effect of corridors is masked by ongoing gene flow. Nonetheless, results based on a larger number of shared private alleles at neutral loci between fragment pairs found after the establishment of corridors in Mandena suggest that gene flow is augmented as a result of enhanced connectivity. Our data points out that despite low effective population size, M. ganzhorni maintains high individual heterozygosity at neutral loci and at MHC II DRB gene and that selection plays a predominant role in maintaining MHC diversity. These findings highlight the importance of long-term genetic monitoring in order to disentangle between the processes of drift and selection maintaining adaptive genetic diversity in small populations.

opencc-zeroDec 2010View details →

Data from: Ecologically relevant dispersal of corals on isolated reefs: implications for managing resilience

Coral reefs are in decline worldwide, and marine reserve networks have been advocated as a powerful management tool for maximizing the resilience of coral communities to an increasing variety, number, and severity of disturbances. However, the effective design of reserves must account for the spatial scales of larval dispersal that affect the demography of communities over ecological time frames. Ecologically relevant distances of dispersal were inferred from DNA microsatellite data in a broadcast-spawning (Acropora tenuis) and a brooding (Seriatopora hystrix) coral at isolated reef systems off northwest Australia. Congruent with expectations based on life histories, levels of genetic subdivision among populations were markedly higher in the brooder than in the broadcast spawner. Additionally, significant subdivision for both species between systems (>100 km), and between (>10 km) or within reefs (<10 km) within systems, indicated that many reefs or reef patches are demographically independent. There was also a clear distinction in the scale of genetic structure between the different systems; at the more geographically complex of the systems, a much finer scale structure was detected in both species. This suggested that the hydrodynamics associated with these complex reefs restrict distances regularly traveled by larvae. The primary implication is that short-term recovery of these coral communities after severe disturbance requires the input of larvae from viable communities kilometers to a few tens of kilometers away. Therefore, to be self-sustaining, we suggest that coral reef protected areas need to be large enough to encompass these routine dispersal distances. Further, to facilitate recovery from severe disturbances, protected areas need to be replicated over these spatial scales. However, specific designs also need to account for size, complexity, and isolation of reefs, which will either restrict or enhance dispersal within this range.

Data from: Nest survival modeling using a multi-species approach in forests managed for timber and biofuel feedstock

1. Switchgrass (Panicum virgatum) intercropping is a novel forest management practice for biomass production intended to generate cellulosic feedstocks within intensively managed loblolly pine-dominated landscapes. These pine plantations are important for early-successional bird species, as short rotation times continually maintain early successional habitat. We tested the efficacy of using community models compared to individual surrogate species models in understanding influences on nest survival. We analysed nest data to test for differences in habitat use for 14 bird species in plots managed for switchgrass intercropping and controls within loblolly pine (Pinus taeda) plantations in Mississippi, USA. 2. We adapted hierarchical models using hyper-parameters to incorporate information from both common and rare species to understand community-level nest survival. This approach incorporates rare species that are often discarded due to low sample sizes, but can inform community-level demographic parameter estimates. We illustrate use of this approach in generating both species-level and community-wide estimates of daily survival rates for songbird nests. We were able to include rare species with low sample size (minimum n = 5) to inform a hyper-prior, allowing us to estimate effects of covariates on daily survival at the community level, then compare this with a single-species approach using surrogate species. Using single species models, we were unable to generate estimates below a sample size of 21 nests per species. 3. Community model species-level survival and parameter estimates were similar to those generated by five single species models, with improved precision in community model parameters. 4. Covariates of nest placement indicated that switchgrass at the nest site (< 4 m) reduced daily nest survival, although intercropping at the forest stand level increased daily nest survival. 5. Synthesis and applications. Community models represent a viable method for estimating community nest survival rates and effects of covariates while incorporating limited data for rarely detected species. Intercropping switchgrass in loblolly pine plantations slightly increased daily nest survival at the research plot scale (0.1 km2), although at a local scale (50 m2) switchgrass negatively influenced nest survival. A likely explanation supported by previous research is intercropping shifted community composition, favouring species with greater disturbance tolerance.

opencc-zeroDec 2015View details →

Data from: Manipulating wetland hydroperiod to improve occupancy rates by an endangered amphibian: modelling management scenarios

Environmental managers have the difficult task of ensuring species persistence despite considerable uncertainty about their response to management. Spatially explicit population models provide one solution for simulating the dynamics of species and evaluating alternative management regimes. We used a Bayesian model to investigate wetland occupancy dynamics of the endangered growling grass frog Litoria raniformis at a wastewater treatment plant in southern Victoria, Australia. We coupled prior information from earlier research on this species with our survey data to quantify the effects of patch-scale variables and connectivity on the probabilities of occupancy, population extinction and colonization. Hydroperiods of 13 sites were experimentally enhanced to bolster occupancy rates by L. raniformis. We used simulations to assess the extent to which the enhanced hydroperiod regime improved the viability of the focal metapopulation. Occupancy rate increased by 15% among the enhanced sites in 2013–2014, whereas the rate of occupancy among unenhanced sites fell by 11% in that year. Forward simulation using the dynamic occupancy model suggested that the minimum occupancy rate across the metapopulation would be 18% higher if the enhanced hydroperiod regime was retained over the next 20 years. Mean posterior effects of patch-scale variables and connectivity on the occupancy dynamics of L. raniformis were consistent with the prior effect in all cases, with only small changes to the size of these effects. There was no clear effect of water chemistry on occupancy dynamics. Synthesis and applications. This work suggests that managing the hydroperiod of constructed wetlands can be an effective tool for the conservation of amphibians and demonstrates the utility of spatially explicit models for assessing metapopulation viability. We encourage managers to experimentally test the efficacy of manipulating patch-scale variables to improve occupancy rates within amphibian metapopulations.

opencc-zeroDec 2015View details →

Data from: Restricted grouper reproductive migrations support community-based management

Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small—the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km2. This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km2 using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km2 no-take LMMA to 1–2 km2 would protect approximately 30–50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.

Data from: Effects of water level and grassland management on alpha and beta diversity of wet grassland birds in restored wetlands

Nearly 60% of European wetlands have been lost to drainage or to the cessation of grassland management. Large amounts of resources are put into wetland restoration with the aim to recover biodiversity. However, few studies have simultaneously evaluated effects of management, wetness and flooding dynamics on biodiversity of restored wetlands such as seasonally flooded wet grasslands. We inventoried bird communities over 4 years at 137 sites (each 3·1 ha) within five restored wet grassland areas in Sweden to investigate whether species richness and occurrence of 12 common wet grassland species were related to (i) local conditions such as management (grazing, mowing and unmanaged areas), basic wetness and spring flooding dynamics. Further, we investigated whether (ii) the composition of the adjacent landscape (20 ha) related to local bird diversity and (iii) species turnover (i.e. beta diversity) differed between sites characterized by their basic wetness, degree of flooding and predominant management regime. Local species richness was positively linked to degree of flooding and basic wetness of grasslands but not to type of grassland management. Species richness tended also to be negatively linked to proportion of forest at the landscape scale. Although variable, the same results were also true concerning the probability of the occurrence of a single species at the local scale. Species turnover between sites, and thus total species richness, was distinctly higher in (i) grazed as compared to mowed grasslands except in dry non-flooded grasslands and (ii) flooded as compared to non-flooded sites. Similar patterns held for the subset of 12 red-listed species. We suggest that the high beta diversity in grazed and flooded grasslands is driven by the heterogeneous vegetation structure, resulting in good conditions for foraging and nesting for several wet grassland bird species. Synthesis and applications. The selection of wetlands for conserving wet grassland birds should prioritize temporary flooded grasslands of moderate wetness, preferably far from forest edges. Restoration and management of wet grasslands should include water level management, removal of shrubs and trees, and low-intensity grazing, whereas mowing could be used in non-flooded grasslands of low basic wetness.

Data from: Phylogenetic measures of plant communities show long-term change and impacts of fire management in tallgrass prairie remnants

1. Phylogenies are increasingly incorporated into ecological studies on the basis that evolutionary relatedness broadly correlates with trait similarity. However, phylogenetic approaches have rarely been applied to monitoring long-term community change or guiding management. 2. We analysed a 25-year resampling data set (1976–2001) of 41 tallgrass prairie remnants (Illinois, USA) to test for phylogenetic signals of plant community structure, change, environmental associations, fire management and functional traits. A community phylogeny was constructed using GenBank sequences and trait data were acquired from the TRY consortium. Phylogenetic measures of alpha and beta diversity were compared with taxonomic and functional measures. 3. From 1976–2001, communities became more phylogenetically clustered relative to null model expectations, i.e. increasingly restricted to subsets of species more closely related than expected by chance. Phylogeny was a sensitive indicator of environmental gradients and fire management. There were strong relationships between phylogeny and traits: key traits were phylogenetically non-random and phylogenetic diversity was a necessary complement to species richness for explaining variation in trait diversity. 4. Phylogeny revealed a shift in community structure over time, with sites having been phylogenetically random in 1976 but becoming differentiated from each other by 2001. In contrast, measures of taxonomic and functional diversity showed differentiation at both time points. Phylogenetic patterns likely reflected changes in species' abundances mediated by the influence of environmental conditions and fire frequency. 5. Synthesis and applications. Phylogenetic analyses can elucidate factors central to sound monitoring and management of plant communities. In this system, phylogeny was not a proxy for other indicators, but provided information complementing taxonomic-based and trait-based approaches for understanding vegetation structure, change and response to fire management. Phylogenetic approaches to ecological analysis are increasingly accessible, but fuller understanding of phylogeny–trait relationships and further development of user-friendly analytical tools are needed for phylogenetics to widely inform restoration and management. In some systems, targeting phylogenetic diversity may be an effective means for restoring functionally diverse plant communities.

Data from: Restoration and management for plant diversity enhances the rate of belowground ecosystem recovery

The positive relationship between plant diversity and ecosystem functioning has been criticized for its applicability at large scales and in less controlled environments that are relevant to land management. To inform this gap between ecological theory and application, we compared recovery rates of belowground properties using two chronosequences consisting of continuously cultivated and independently restored fields with contrasting diversity management strategies: grasslands restored with high plant richness and managed for diversity with frequent burning (n=20) and grasslands restored with fewer species that were infrequently burned (n=15). Restoration and management for plant diversity resulted in 250% higher plant richness. Greater recovery of roots and more predictable recovery of the active microbial biomass across the high diversity management strategy chronosequence corresponded with faster recovery of soil structure. The high diversity grasslands also had greater nutrient conservation indicated by lower available inorganic nitrogen. Thus, mesic grasslands restored with more species and managed for high plant diversity with frequent burning enhances the rate of belowground ecosystem recovery from long-term disturbance at a scale relevant to conservation practices on the landscape.

opencc-zeroDec 2018View details →

Data from: Detection and initial management of gestational diabetes through primary health care services in Morocco: an effectiveness-implementation trial

Background: Gestational Diabetes Mellitus (GDM) testing and management in Morocco is associated with delays resulting in late commencement of treatment. To reduce delays and to increase access of women to GDM care, a country-adapted intervention targeting primary health care providers was designed to test the hypothesis that detection and initial management of GDM at the primary level of care improves newborn outcomes in terms of lower birthweights and less cases of macrosomia and impacts on maternal weight gain, glucose balance and pregnancy outcomes. Materials and methods: We conducted a cluster randomized controlled trial in two districts of Morocco. In each district, 10 health centers were randomly selected to serve either as intervention or control sites. Pregnant women attending antenatal care in the study facilities were eligible to participate. At the intervention sites, women were offered GDM screening by capillary glucose testing following International Association of Diabetes in Pregnancy Study Groups/WHO criteria. Women diagnosed with GDM received counselling on nutrition and exercise and were followed up through their health center whereas at control facilities routine practice was applied. Primary outcome was birthweight and secondary outcomes maternal weight gain, glucose control and pregnancy complications. We further assessed GDM prevalence in the intervention arm. Statistical analysis was performed on 210 recruited women. Continuous variables were reported using means while categorical variables using frequencies with tests of independence applying chi-squared tests. Differences of outcome variables between the two groups were estimated by mixed-effects regression models and effect sizes adjusted for confounders. The trial is registered under NCT02979756 at ClinicalTrials.gov. Results: GDM prevalence reached 23.7% in Marrakech. Birthweight in the intervention group was 147grams lower than in the control group (p = 0.08) as was the proportion of macrosomes (3.5% versus 18.4%; p< 0.001). In the intervention arm, women did two times more follow-ups than at control sites (p = 0.001) and mean follow-up intervals were shorter (11.3 days versus 18.7 days; p < 0.001). Overall, 30% more fasting blood sugar values were balanced (p = 0.005) and mean weekly maternal weight gain 49 grams lower (p = 0.032) in the intervention group. More women from control facilities had a delivery complication whereas more newborn complications were observed in women from intervention facilities. No difference between the two groups existed regarding mode of delivery and mean gestational age at delivery. One of the main limitations of the study was the Hawthorn-effect at control sites that might have led to an underestimation of the effect size. Conclusion: A high GDM prevalence in Morocco calls for a context-adapted screening and management approach to enable early interventions. GDM detection and care through antenatal care at primary health facilities may have positively impacted on newborn birthweight but findings are inconclusive. Results of this study will contribute to the decision on a potential upscaling of the intervention in Morocco. Future research could examine long term metabolic changes including diabetes type 2 in the cohort of women and their children.

Data from: Evaluating conservation and fisheries management strategies by linking spatial prioritisation software and ecosystem and fisheries modelling tools

1. Well-designed marine protected area (MPA) networks can deliver a range of ecological, economic and social benefits, and so a great deal of research has focused on developing spatial conservation prioritization tools to help identify important areas. 2. However, whilst these software tools are designed to identify MPA networks that both represent biodiversity and minimize impacts on stakeholders, they do not consider complex ecological processes. Thus, it is difficult to determine the impacts that proposed MPAs could have on marine ecosystem health, fisheries and fisheries sustainability. 3. Using the eastern English Channel as a case study, this paper explores an approach to address these issues by identifying a series of MPA networks using the Marxan and Marxan with Zones conservation planning software and linking them with a spatially explicit ecosystem model developed in Ecopath with Ecosim. We then use these to investigate potential trade-offs associated with adopting different MPA management strategies. 4. Limited-take MPAs, which restrict the use of some fishing gears, could have positive benefits for conservation and fisheries in the eastern English Channel, even though they generally receive far less attention in research on MPA network design. 5. Our findings, however, also clearly indicate that no-take MPAs should form an integral component of proposed MPA networks in the eastern English Channel, as they not only result in substantial increases in ecosystem biomass, fisheries catches and the biomass of commercially valuable target species, but are fundamental to maintaining the sustainability of the fisheries. 6. Synthesis and applications. Using the existing software tools Marxan with Zones and Ecopath with Ecosim in combination provides a powerful policy-screening approach. This could help inform marine spatial planning by identifying potential conflicts and by designing new regulations that better balance conservation objectives and stakeholder interests. In addition, it highlights that appropriate combinations of no-take and limited-take marine protected areas might be the most effective when making trade-offs between long-term ecological benefits and short-term political acceptability.

Data from: Spatial variability in size at maturity of golden king crab (Lithodes aequispinus) and implications for fisheries management

Many crab fisheries around the world are managed by size, sex and season, where males are given at least one opportunity to reproduce before being harvested. Golden king crab (Lithodes aequispinus) supports a commercial fishery in Southeast Alaska and legal size is based on growth and maturity information from other parts of their range. Size at maturity estimates varied for crabs among seven management areas in Southeast Alaska, where male maturity estimates increased in size with increases in latitude while maturity estimates across their North Pacific range decreased in size with increases in latitude. Depth, temperature, and harvest history were not related to variation observed in male maturity estimates. Management implications from this research include reducing legal size in some areas to maximize harvest potential and increasing in others to allow male crab the opportunity to reproduce before being harvested. A more conservative strategy would incorporate the largest maturity estimate thus, increasing the legal size which would have a negative impact to the commercial fishery, but allow male crab the opportunity to reproduce before being harvested. This study shows the importance of understanding how life history characteristics change over space and the challenge incorporating spatial variability for improved fisheries management.

opencc-zeroDec 2015View details →

Data from: Identifying management actions to increase foraging opportunities for shorebirds at semi-intensive shrimp farms

The expansion of aquaculture has resulted in widespread habitat conversion throughout the world. Identifying beneficial management measures may dramatically reduce negative impacts of aquaculture for migratory birds. We studied how densities of foraging shorebirds varied at ponds within a semi-intensive shrimp aquaculture farm on the north-western coast of Mexico, as related to timing of harvest and tidal cycles. Further, we estimated the total daily available area for each shorebird species throughout two entire harvesting seasons at the shrimp farm. High densities (average ca. 50 individuals per ha) of foraging shorebirds were found during the first days following pond harvest. The most abundant species were Willet Tringa semipalmata and Black-necked Stilt Himantopus mexicanus, followed by Marbled Godwit Limosa fedoa and American Avocet Recurvirostra americana. Other regular, but less abundant, species were whimbrel Numenius phaeopus and dowitchers Limnodromus spp. Densities of shorebirds sharply declined daily following harvest. In addition, the time-window availability of harvested ponds was related to each species' foraging behaviour: <2 days for godwits and dowitchers, 4 days for stilts, 5 days for willets and more than a week for avocets and whimbrels. However, birds continued to use harvested ponds that received a low, but continuous water influx. Our results demonstrate that a tropical shrimp farm represents a patchy environment that provides 4·3–12·7% (depending on species) of its total area as foraging opportunities for shorebirds. Synthesis and applications. Sequential harvesting of shrimp aquaculture farm ponds and increasing moisture of the substrate by providing some water supply to harvested ponds, at least throughout the harvesting period, could integrate shorebird conservation into shrimp-farm production. These low-cost and easy management procedures would not increase costs or affect shrimp production – thus representing a win-win opportunity – and would have potential applications for shorebird conservation throughout the world.

Data from: Ecosystem services and disservices provided by small rodents in arable fields: effects of local and landscape management

1. In agriculture, both valuable ecosystem services and unwanted ecosystem disservices can be produced by the same organism group. For example, small rodents can provide biological control through weed seed consumption but may also act as pests, causing crop damage. 2. We studied the hypothesised causal relationships between ecosystem services (removal of weed seeds) and disservices (removal of wheat and crop damage) derived by small rodents (voles and mice) at multiple spatial scales. At the landscape scale, we studied the effects of landscape compositional and configurational heterogeneity along the former inner German border in east and west Germany on the abundance of voles and mice and their related ecosystem services and disservices. At the local scale, we studied how this abundance and ecosystem functions are affected by management intensity (organic vs. conventional winter wheat), associated differences in crop characteristics and edge effects. 3. Linear mixed effects models and path analysis show that voles drive ecosystem disservices, but not ecosystem services, in agricultural fields. Daily wheat seed removal by voles was influenced by increasing wheat height and was almost three times higher than weed seed removal, which was not related to local or landscape-scale effects. 4. Abundance of voles and associated crop damage decreased with lower crop density and higher wheat height, which were associated with organic farming. Abundance of voles and crop damage were highest in conventional fields in west Germany. 5. Synthesis and applications. As the ecosystem disservice of wheat seed consumption by voles and mice must be considered mainly during crop sowing, management before harvest should focus on decreasing the pest potential of voles' but not mice. Our results suggest that densities of voles and their ecosystem disservices could be reduced by having fields with low crop density and high wheat height, practices associated with organic farming. Surrounding landscapes with low compositional and configurational heterogeneity could further reduce voles' pest potential, but with probable negative effects on farmland biodiversity.

Data from: Habitat restoration promotes pollinator persistence and colonization in intensively managed agriculture

Widespread evidence of pollinator declines has led to policies supporting habitat restoration including in agricultural landscapes. Yet, little is yet known about the effectiveness of these restoration techniques for promoting stable populations and communities of pollinators, especially in intensively managed agricultural landscapes. Introducing floral resources, such as flowering hedgerows, to enhance intensively cultivated agricultural landscapes is known to increase the abundances of native insect pollinators in and around restored areas. Whether this is a result of local short-term concentration at flowers or indicative of true increases in the persistence and species richness of these communities remains unclear. It is also unknown whether this practice supports species of conservation concern (e.g., those with more specialized dietary requirements). Analyzing occupancies of native bees and syrphid flies from 330 surveys across 15 sites over eight years, we found that hedgerow restoration promotes rates of between-season persistence and colonization as compared with unrestored field edges. Enhanced persistence and colonization, in turn, led to the formation of more species-rich communities. We also find that hedgerows benefit floral resource specialists more than generalists, emphasizing the value of this restoration technique for conservation in agricultural landscapes.

opencc-zeroJul 2019View details →

Data from: Variation across river channels in demographic dynamics of a riparian herb with threatened status: management and conservation implications

PREMISE OF THE STUDY: Gesneria pauciflora is a rare-threatened plant growing in riparian forests. Periodic disturbances, expected in this habitat, could influence demographic dynamics on plant populations, yet their impact may not be the same across watershed. We hypothesize that differences in disturbances between the main-channel and tributaries may lead to spatial dissimilarities in population growth rate (λ), structure, and fecundity. METHODS: 1277 plants were tagged and monitored over a 1.5-years period. Every 6-months we measured plant size, survival and fecundity, in addition to appearance of seedlings. These variables were applied in Integral Projection Models to assess the population status of G. pauciflora. KEY RESULTS: Plants in the main-channel were smaller but were more likely to flower and fruit than those in the tributaries. Overall mortality was greater in the main-channel and more so during the rainy season. At both sites λ ranged from 0.9114-0.9865, and survival/growth of larger plants had a greater effect on lambda (> 0.90) regardless of site. CONCLUSIONS: Lambda values suggest that G. pauciflora is declining across the watershed. Higher mortality rates in the main channel (more-perturbed sites) might driving G. pauciflora to reproduced at smaller sizes, while the tributaries (less-perturbed sites) may benefit growth and lead to larger plant sizes. Extreme climatic events are expected to increase in the Caribbean and might decrease the population if left unmanaged. Management strategies that reduce the time plants require to reach larger sizes might be necessary to increase λ, and reintroduction of cuttings might be a possible solution.

opencc-zeroDec 2018View details →

Data from: Chromosomal inversions in the Atlantic cod genome: implications for management of Canada's Northern cod stock

Following stock collapse and over twenty years of moratoria, the state of Canada's Northern Atlantic cod (Gadus morhua) remains precarious. To test if recent stock growth was of endogenous or exogenous origin, we performed a whole genome scan (ddRAD) on 135 adults captured in 2015 at three offshore spawning locations spanning the range of the offshore stock along the northeastern Newfoundland and Labrador shelf (Hawke Channel, Notre Dame Channel and Bonavista Corridor), with an additional 105 adults from three more southern locations (St. Anns Bank, Browns Bank and Bay of Fundy). Population structure analysis using 5,077 single nucleotide polymorphisms (SNPs) detected a distinct genetic break off the coast of Nova Scotia near 45 °N. Gene flow between groups north and south of this divide appears to be limited despite the presence of several northern-type and admixed individuals present in the southern area. North of the genetic divide, allele frequencies of neutral loci were indicative of a panmictic population. Several outlier SNPs were found to be associated with ecologically relevant physical characteristics (visual pigments, fin development, response to hypoxia, and various metabolic processes), which may be indicative of different ecological niches.

Data from: Territory surveillance and prey management: wolves keep track of space and time

Identifying behavioral mechanisms that underlie observed movement patterns is difficult when animals employ sophisticated cognitive-based strategies. Such strategies may arise when timing of return visits is important, for instance to allow for resource renewal or territorial patrolling. We fitted spatially explicit random-walk models to GPS movement data of six wolves (Canis lupus; Linnaeus, 1758) from Alberta, Canada to investigate the importance of the following: (1) territorial surveillance likely related to renewal of scent marks along territorial edges, to reduce intraspecific risk among packs, and (2) delay in return to recently hunted areas, which may be related to anti-predator responses of prey under varying prey densities. The movement models incorporated the spatiotemporal variable "time since last visit," which acts as a wolf's memory index of its travel history and is integrated into the movement decision along with its position in relation to territory boundaries and information on local prey densities. We used a model selection framework to test hypotheses about the combined importance of these variables in wolf movement strategies. Time-dependent movement for territory surveillance was supported by all wolf movement tracks. Wolves generally avoided territory edges, but this avoidance was reduced as time since last visit increased. Time-dependent prey management was weak except in one wolf. This wolf selected locations with longer time since last visit and lower prey density, which led to a longer delay in revisiting high prey density sites. Our study shows that we can use spatially explicit random walks to identify behavioral strategies that merge environmental information and explicit spatiotemporal information on past movements (i.e., "when" and "where") to make movement decisions. The approach allows us to better understand cognition-based movement in relation to dynamic environments and resources.