Data integration for large-scale models of species distributions

With the expansion in the quantity and types of biodiversity data being collected, there is a need to find ways to combine these different sources to provide cohesive summaries of species’ potential and realized distributions in space and time. Recently, model-based data integration has emerged as a means to achieve this by combining datasets in ways that retain the strengths of each. We describe a flexible approach to data integration using point process models, which provide a convenient way to translate across ecological currencies. We highlight recent examples of large-scale ecological models based on data integration and outline the conceptual and technical challenges and opportunities that arise

Worldwide occurrence records suggest a global decline in bee species richness

Wild and managed bees are key pollinators, ensuring or enhancing the reproduction of a large fraction of the world's wild flowering plants and the yield of ∼85% of all cultivated crops. Recent reports of wild bee decline and its potential consequences are thus worrisome. However, evidence is mostly based on local or regional studies; the global status of bee decline has not been assessed yet. To fill this gap, we analyzed publicly available worldwide occurrence records from the Global Biodiversity Information Facility spanning over a century. We found that after the 1990s, the number of collected bee species declines steeply such that approximately 25% fewer species were reported between 2006 and 2015 than before the 1990s. Although these trends must be interpreted cautiously given the heterogeneous nature of the dataset and potential biases in data collection and reporting, results suggest the need for swift actions to avoid further pollinator decline. Wild bee pollination is fundamental to the reproduction of hundreds of thousands of wild plant species and is key to securing adequate yields in about 85% of food crops. Declines in the abundance and diversity of bee species have been reported at local, regional, and country levels on different continents, but up to now there has not been a long-term assessment on global trends. We turned to publicly available data on specimen collections and observations gathered at the Global Biodiversity Information Facility, mostly coming from museum and academic collections and complemented by citizen-science efforts. We found that the number of bee species being collected or observed over time has been steadily declining since the 1990s. Although these results might in part reflect increased impediments to specimen collection and data mobilization, as well as reduced sampling coverage, they could also reflect a worldwide decline in bee diversity given that many species are becoming rarer and less likely to be found. Wild bees are key to pollination of wild and crop plants, and local and regional reports of their decline are cause for concern. Since there are no global long-term datasets of bee diversity, we analyzed historical occurrence data from collections and observations gathered by the Global Biodiversity Information Facility and found that the number of bee species worldwide has been steadily decreasing since the 1990s as a result of either concerted changes in data-gathering strategies or, most likely, an actual global decline in bee diversity.Fil: Zattara, Eduardo Enrique. Indiana University; Estados Unidos. National Museum Of Natural History. Departamento de Zoología. Area de Invertebrados; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Wissenschaftskolleg zu Berlin; Alemani

A new comprehensive trait database of European and Maghreb butterflies, Papilionoidea

Trait-based analyses explaining the different responses of species and communities to environmental changes are increasing in frequency. European butterflies are an indicator group that responds rapidly to environmental changes with extensive citizen science contributions to documenting changes of abundance and distribution. Species traits have been used to explain long- and short-term responses to climate, land-use and vegetation changes. Studies are often characterised by limited trait sets being used, with risks that the relative roles of different traits are not fully explored. Butterfly trait information is dispersed amongst various sources and descriptions sometimes differ between sources. We have therefore drawn together multiple information sets to provide a comprehensive trait database covering 542 taxa and 25 traits described by 217 variables and sub-states of the butterflies of Europe and Maghreb (northwest Africa) which should serve for improved trait-based ecological, conservation-related, phylogeographic and evolutionary studies of this group of insects. We provide this data in two forms; the basic data and as processed continuous and multinomial data, to enhance its potential usage

Combining range and phenology shifts offers a winning strategy for boreal Lepidoptera

Species can adapt to climate change by adjusting in situ or by dispersing to new areas, and these strategies may complement or enhance each other. Here, we investigate temporal shifts in phenology and spatial shifts in northern range boundaries for 289 Lepidoptera species by using long-term data sampled over two decades. While 40% of the species neither advanced phenology nor moved northward, nearly half (45%) used one of the two strategies. The strongest positive population trends were observed for the minority of species (15%) that both advanced flight phenology and shifted their northern range boundaries northward. We show that, for boreal Lepidoptera, a combination of phenology and range shifts is the most viable strategy under a changing climate. Effectively, this may divide species into winners and losers based on their propensity to capitalize on this combination, with potentially large consequences on future community composition.Peer reviewe

An analytical framework for spatially targeted management of natural capital

A major sustainability challenge is determining where to target management to enhance natural capital and the ecosystem services it provides. Achieving this understanding is difficult, given that the effects of most actions vary according to wider environmental conditions; and this context dependency is typically poorly understood. Here, we describe an analytical framework that helps meet this challenge by identifying both why and where management actions are most effective for enhancing natural capital across large geographic areas. We illustrate the framework’s generality by applying it to two examples for Britain: pond water quality and invasion of forests by rhododendron

Does a short pollard walk transect capture butterfly and bee diversity? A test to inform pollinator monitoring and community science initiatives

1. Widespread declines in insects will threaten ecosystem functioning and services. Nevertheless, a lack of data hinders assessments of population and biodiversity trends for many insect groups and thus effective conservation actions. Implementing cost-effective, unbiased, and accurate monitoring programmes targeting different groups across a larger geographical range has therefore become a key conservation priority. 2. We evaluated a sampling protocol designed for community science initiatives targeting butterflies and bees. Specifically, we tested how well a short (200-m long) version of traditional Pollard walk transects, designed to be accessible for large numbers of community scientists, captures changes in alpha and beta diversity of these two pollinator groups. 3. We used resampling methods to simulate and assess scenarios varying in sampling intensity and frequency. We found that alpha and beta diversity of butterflies and bees were estimated at similar accuracies across different scenarios, which suggests that even short transects can provide useful information on diversity patterns for both taxa. However, common sampling frequencies resulted in low accuracies (e.g. one sample every 10 days finds on average ~50% of the species present at a site). 4. We discuss our results in the context of developing large scale, structured monitoring systems for multiple insect taxa, and how information on biodiversity patterns can inform the expansion of monitoring schemes. We explain why, moving forward, even rapid sampling designs similar to the approach tested here will be useful given a higher potential to involve community scientists, data integration techniques, and the opportunities to sample under-represented habitat type

Optimal pollination thresholds to maximize blueberry production

Pollination management for highbush blueberry crops (Vaccinium spp.) generally depends on beehives stocked at variable densities, with little consideration given to optimal pollination levels dictated by the mating system of the crop. This approach limits our capability to accurately forecast the consequences of animal pollination on crop productivity and can result in pollination shortfalls. Using experimental and observational data, we estimated optimal pollination thresholds for blueberry crops that maximize fruit diameter. We manipulated stigmatic pollen loads and used Bayesian models to evaluate the effects on fruit diameter. In this way, we were able to define thresholds for deficient, optimal and supraoptimal pollen deposition in blueberries. These thresholds were then evaluated under field conditions in blueberry farms, and used simulations to estimate the minimum number of honeybee visits required for optimal blueberry pollen deposition. A quadratic relationship described fruit diameter in response to stigmatic pollen load, with optimal pollen deposition peaking at 192 pollen tetrads and ranging between 112 and 274. Our simulations showed that a flower visitation rate guaranteeing, on average, six to seven honeybee visits per flower (i.e. flower visitation rate of 0.6 visits per 100 flowers h−1) would result in 60% of the plant flowers receiving optimum stigmatic pollen deposition. Higher numbers of honeybee visits increased the probability that blueberry stigmatic pollen loads were below the optimum and the probability that smaller berries were produced. We show that adverse pollination scenarios in blueberries can occur through different pathways, either because of a deficit or an excess of pollination that directly impacts the quality of the fruits produced. By identifying thresholds, we provide a pragmatic basis for adaptive management of honeybees based on average visitation rates that are most suitable for growers to manipulate. Our study provides new insights into the mechanisms behind pollination, fruit production, and the contribution of honeybee to blueberry crops. We highlight that systematic pollination management through flower visitation monitoring and clear optimal pollination targets can help prevent detrimental pollination scenarios

Soybean dependence on biotic pollination decreases with latitude

Identifying large-scale patterns of variation in pollinator dependence (PD) in crops is important from both basic and applied perspectives. Evidence from wild plants indicates that this variation can be structured latitudinally. Individuals from populations at high latitudes may be more selfed and less dependent on pollinators due to higher environmental instability and overall lower temperatures, environmental conditions that may affect pollinator availability. However, whether this pattern is similarly present in crops remains unknown. Soybean (Glycine max), one of the most important crops globally, is partially self-pollinated and autogamous, exhibiting large variation in the extent of PD (from a 0 to ∼50% decrease in yield in the absence of animal pollination). We examined latitudinal variation in soybean’s PD using data from 28 independent studies distributed along a wide latitudinal gradient (4–43 degrees). We estimated PD by comparing yields between open-pollinated and pollinator-excluded plants. In the absence of pollinators, soybean yield was found to decrease by an average of ∼30%. However, PD decreases abruptly at high latitudes, suggesting a relative increase in autogamous seed production. Pollinator supplementation does not seem to increase seed production at any latitude. We propose that latitudinal variation in PD in soybean may be driven by temperature and photoperiod affecting the expression of cleistogamy and androsterility. Therefore, an adaptive mating response to an unpredictable pollinator environment apparently common in wild plants can also be imprinted in highly domesticated and genetically-modified crops

Rewiring of interactions in a changing environment: nettle‐feeding butterflies and their parasitoids

Climate and land use change can alter the incidence and strength of biotic interactions, with important effects on the distribution, abundance and function of species. To assess the importance of these effects and their dynamics, studies quantifying how biotic interactions change in space and time are needed. We studied interactions between nettle‐feeding butterflies and their shared natural enemies (parasitoids) locally and across 500 km latitudinal gradient in Sweden. We also examined the potential impact of the range‐expansion of the butterfly Araschnia levana on resident butterflies via shared parasitoids, by studying how parasitism in resident butterflies covaries with the presence or absence of the newly‐established species. We collected 6777 larvae of four nettle‐feeding butterfly species (Aglais urticae, Aglais io, Ar. levana and Vanessa atalanta), over two years, at 19 sites distributed along the gradient. We documented the parasitoid complex for each butterfly species and measured their overlap, and analysed how parasitism rates were affected by butterfly species assemblage, variations in abundance, time, and the arrival of Ar. levana. Parasitoids caused high mortality, with substantial overlap in the complex of parasitoids associated with the four host butterflies. Levels of parasitism differed significantly among butterflies and were influenced by the local butterfly species assemblage. Our results also suggest that parasitism in resident butterflies is elevated at sites where Ar. levana has been established for a longer period. In our study system, variations in butterfly species assemblages were associated in a predictable way with substantial variations in rates of parasitism. This relationship is likely to affect the dynamics of the butterfly host species, and potentially cascade to the larger number of species with which they interact. These results highlight the importance of indirect interactions and their potential to reorganise ecological communities, especially in the context of shifts in species distributions in a warmer world