Search

Recent actions to mitigate biodiversity loss in agricultural environments appear insufficient despite the considerable efforts channeled via the European Union’s Common Agricultural Policy. One likely reason for this failure is the limited attention paid to the regional and landscape level ecological characteristics in farmland conservation planning. We demonstrate how to obtain conservation prioritization solutions that would address simultaneously three goals, including two landscape level targets: minimizing local habitat quality loss, maximizing habitat connectivity, and incorporating landscape heterogeneity. As these goals may be contradictory, we investigate the potential trade-offs between them. We used the Zonation prioritization tool to examine how our three goals could be implemented in the agricultural landscapes of southwest Finland. We used measures of (i) biodiversity value of grasslands, (ii) connectivity between grasslands, and (iii) landscape heterogeneity which comprised of (land cover type based) compositional heterogeneity and (field margin based) configurational heterogeneity. Integration of landscape heterogeneity measures and habitat connectivity resulted in some tradeoffs with local habitat quality, the most prominent observation being that landscape heterogeneity co-varied with grassland connectivity. Among the two landscape heterogeneity parameters, inclusion of compositional heterogeneity resulted in more clustered prioritization solutions than configurational heterogeneity, which had a spatially more balanced impact. Concordance among landscape scale factors implies high potential for reconstruction of a functioning network of semi-natural grasslands in areas under intensive agricultural use. Broader scale multi-objective planning approaches can thus importantly support targeting biodiversity conservation planning and mediating the implementation of Common Agricultural Policy objectives. peerReviewed

The amount of High Nature Value farmland (HNVf) is a commonly used environmental indicator for assessing the performance of the Common Agricultural Policy, to support sustainable agriculture and monitor changes in agricultural land use in Europe. HNVf comprises agricultural areas of semi-natural state, low-intensity farming and fine-scale landscape mosaics of different habitat types. For a successful implementation, the identification of HNVf should correctly reflect the variation in biodiversity values between different agricultural landscapes. We examined how well the Finnish HNVf indicator and the sub-indicators constituting it – recalculated for the purposes of this study for five study regions – reflect the variation in bird and butterfly species richness and diversity patterns at different spatial scales. We found that butterfly diversity index was positively associated with the HNVf indicator at the finest scale of 0.5 km × 0.5 km squares. Among the HNVf sub-indicators, extensive cultivation of grasslands was most strongly related to the farmland bird diversity and the density of edge to the butterfly diversity. Thus, the HNVf concept reflects well the distribution of butterflies in the Finnish agricultural landscapes but insufficiently the diversity patterns of farmland birds. Importantly, semi-natural vegetation and long-term pastures – the backbone of the concept – presently occur in small and highly fragmented patches in agricultural landscapes in Finland. The Pan-European concept of HNVf has restricted application to farmland birds of this boreal country and the national HNVf concept may need to be revised.

Set-asides sown to wildflowers are introduced to promote agrobiodiversity. Often, sown seed mixtures have been used to enhance aboveground biodiversity while belowground biodiversity has received less attention. We studied in a 15-year-old set-aside experiment, the impact of seed mixtures (grass vs. meadow) and mowing (mown vs. unmown) on the abundance and diversity of plants, two aboveground invertebrate groups (pollinators and natural enemies of pest species) and one key belowground group, earthworms. We also studied the treatment effects on selected soil chemical properties. In general, a sown meadow seed mixture mostly benefitted aboveground biodiversity, whereas the impacts of late-season mowing were most discernible for earthworms. Plant species richness or coverage did not differ between seed mixtures, but plant coverage showed a positive response to mowing, while the impact on species richness was minor. The meadow seed mixture was dominated by Centaurea jacea. A non-mown meadow treatment supported the highest earthworm density and species richness, while the values were lowest in the mown meadow, where earthworm total mass was also at its lowest. In a grass seed mixture of intermediate density and richness, the mowing had no measurable effect on the earthworm community. Topsoil carbon, nitrogen and soluble phosphorus concentrations showed a typical gradient for non-inverted soils, with the highest concentrations in the 0–2.5 cm layer. The two uppermost soil layers (to 5 cm depth) had higher soluble phosphorus content under grass than under meadow seed mixture. Abundance of natural enemies of pests was not significantly different between the treatments, but for carabids there was a marginally significant positive response to mowing. Bumblebee species richness and the abundance of bumblebees and honeybees were highest in the mown meadow seed mixture plots. Butterfly species richness was marginally significantly higher in mown than in non-mown treatments in both seed mixtures. The results showed the potential of set-asides to promote both aboveground and belowground biodiversity through increased plant diversity.

Conservation translocation is a controversial, yet sometimes the only applicable, conservation tool in the face of the human-induced environmental change. One important aspect often neglected in translocation experiments is predicting the spatial expansion potential of the translocated population in the release area. In this study, we used a spatially explicit movement model to project the expansion rate of a translocated clouded Apollo (Parnassius mnemosyne) population. The model was parameterised with data collected from the source population inhabiting an open landscape with well-connected habitat patches. We then used these parameter estimates to simulate the spread of the translocated population in the new area, which was a forested landscape with more fragmented habitat. We tested the model predictions by comparing them to the observed expansion rate between 2000 and 2016. Additionally, we tested whether including annually varying weather conditions would increase realism in the projections. Model predictions were qualitatively correct and quantitatively most accurate for flight seasons with prevailing weather conditions similar to those of the season when the data for parameter estimation was collected. We conclude that spatially explicit movement models are potential tools to improve the planning of future conservation translocations in terms of choosing the optimal release area, as they enable the comparison of functional connectivities even between structurally different landscapes. However, our results suggest that a model fitted based on movement data from a single year may not be representative for the overall dispersal rates due to temporal variation in dispersal.

Success rates for conservation translocations of species are low and there is a need for increased understanding of how this activity is best applied. Here, using static species distribution models and a spatially-explicit dynamic simulation model, RangeShifter, we examine the impacts of habitat cover in recipient landscapes, allocation of individuals into multiple sites and species trait characteristics on the long-term fate of hypothetical translocations of a grassland specialist butterfly, Maniola jurtina, in Finland. While persistence of populations introduced to climatically suitable locations northwards of the current range can be increased by selecting sites with increasing habitat cover and by allocation of individuals to multiple release sites, local population growth rate is shown to be the key parameter in determining likely translocation success. We conclude that the long-term persistence of translocated habitat specialist butterflies, particularly with low growth rates, appears to be uncertain in modern-day fragmented grassland networks and that translocation activities should prioritize management that improves local growth rate.

Translocations have been advocated as a conservation tool helping species adapt to climate and land-use change, but well-documented examples of invertebrates’ translocations are rare. The paper describes a successful translocation of the threatened Clouded Apollo butterfly ( Parnassius mnemosyne ) in Finland, compares this to a specific failed translocation, and presents conclusions for conservation planning as to factors contributing to the success. Two apparent key characteristics of the successful translocation were greater abundance of larval resources and less open landscape. The successful site was surrounded by forest, which strongly restricted emigration, crucially supporting the survival of the small initial population. Based on 20 mated females’ translocation in 2000, the local population increased slowly, reaching 600 butterflies in 2011. A large translocation patch together with host-plant abundance enabled successful establishment of the local population. Availability of other suitable grassland patches sufficiently nearby was an additional key characteristic, facilitating the Clouded Apollo’s expansion. However, the expansion rate was low; it took seven years for the butterflies to colonise the five nearest patches, only 10–200 m from the translocation patch. By 2013, they had colonised all suitable semi-natural grassland patches within 2 km from the translocation site and established a seemingly viable metapopulation with 11 subpopulations. The results point to the significance of local habitat area and landscape quality, along with conditions restricting emigration, in determination of suitable translocation sites.

This paper studies joint provision of two environmental non-market commodities related to agriculture: biodiversity conservation and water protection. We provide an optimising tool for analysing spatial dependencies of multifunctional agriculture at catchment scale. We show that efficiency gains can be achieved by spatial allocation and choice of the type of vegetation. In particular, inclusion of meadow nectar plants in the founding grass seed mixture of set-asides was found out to be an economically efficient measure to promote biodiversity and water protection on warm, steep slopes.

Biodiversity indicators are assumed to reflect changes in e.g. species richness of multiple taxa, but correlations in species richness between taxa have often been shown to be weak. However, only few studies are based on data allowing for rigorous tests whether strengths of correlations differ between habitat and landscape factors. We compared strengths of correlations between species richness of butterflies, plants and farmland birds between habitats (semi-natural grasslands, forest verges or field boundaries), spatial scales (0.8 ha, 25 ha and 50 ha) and landscapes differing in heterogeneity and regional land-use intensity. Between habitats, the correlation between butterflies and plants was strongest in semi-natural grasslands. Also concerning butterflies and plants, the correlation was weakest at the 0.8 ha scale, but no consistent scale-dependent patterns were found between plants and farmland birds. In a regional context, butterfly and plant species richness were consistently positively correlated, whereas when involving farmland birds we found correlations between taxa to be weaker and/or not significant in regions with high agricultural land-use intensity and in homogeneous landscapes. In general, species richness was consistently congruent only between butterflies and plants, whereas correlations involving farmland birds were mainly weak and showed contrasting patterns depending on regional context. Increasing landscape heterogeneity thus increased congruence amongst all studied taxa, but in different contexts and due to different underlying mechanisms. Although plants were involved in most of the significant correlations we cannot recommend a particular taxon as a general diversity indicator.

Sown wildflower strips have been used to mitigate against the loss of farmland biodiversity e.g. as a part of agri-environmental schemes. In this four-year field experiment, conducted on six field parcels, the ability of wildflower strips to simultaneously promote the availability of pollination services (using bumblebee abundance as a proxy), species diversity (total species richness of bumblebees, butterflies and diurnal moths) and conservation (abundance of habitat specialist butterflies) was evaluated. The results showed that the first two indicators increased strongly and rapidly in wildflower strips until the third year of the experiment. The conservation indicator increased more slowly and this response was related to the forest cover of the surrounding landscape. Furthermore, the benefits of wildflower strips were largely independent of experimentally varied strip properties. It is concluded that wildflower strips are a flexible mitigation tool to promote different biodiversity targets in agricultural systems. Pollination services and species diversity can be promoted in different kinds of landscapes by ensuring local habitat quality. In the promotion of habitat specialists, landscape matrix quality is more critical.

Agricultural intensification is a major driver of biodiversity decline throughout Europe. Agri-environment schemes governed by EU regulation are a significant tool in combating this decline but despite high spending, experiences of their effectiveness have been mixed. Their effectiveness might be improved by targeting them to locations with high biodiversity value, and particularly by spatial coordination to enhance habitat connectivity and the associated ecological processes, such as dispersal. We show, with an example of semi-natural grassland conservation in South-Western Finland, how spatial conservation planning tools, here the Zonation software, could help in assessing the habitat connectivity and allocating management actions. We assign highest priority to sites that have been classified as nationally important and that have been under management, and let connectivity influence the Zonation prioritizations. According to Zonation outputs, 25–30% of highest-ranking grasslands in our study area are without management contracts, indicating weak connectivity of managed sites, whereas Natura 2000 areas are spatially better located. A 50% expansion of the current network would be adequate to bring its value close to that of a network created from scratch, but as the contracts are temporary, reallocation of the contracts from the least valuable, funded sites to more valuable, unfunded ones would be even more effective. Current policy instruments supporting farmland biodiversity are strongly constrained by EU regulation, and appear to be too inflexible to take the spatial differences in conservation values into account. Better communication and incentives to encourage farmer participation to these voluntary programs are needed.

The importance of rotational fallows for pollinating insects in intensively cultivated farmland was studied in a three-year field experiment. The focus was on the establishment method (undersowing or seed mixture sown post-tillage), seed mixture (competitive Festuca pratensis – Phleum pratense – Trifolium pratense or less competitive Agrostis capillaris – Festuca ovina mixture) and duration (1 or 2 years) of the fallow. The seed mixture and duration affected the pollinators more than the method of establishment. Pollinator species richness was higher in fallows sown with less competitive than with competitive grasses and it increased in the second year. Stubble fields reached as high pollinator species richness already during the first year as fallows with less competitive grasses did in the second year. Pollinator abundance was highest in those treatments in which species richness of flowering plants was highest. The results suggest that the benefits of rotational fallows for pollinators increase when they are established as stubble or using seeds of less competitive grasses and when the field is fallowed for (at least) two summers.

This study examined how species richness of butterflies with differing population trends is affected by land cover and climate. Generalized linear models (GLM) with land cover, climate and geographical location as explanatory variables were constructed to explain variation in species richness of declining, stable and increasing butterflies in 10-km squares in Finland. The largest part of explained variation in species richness of all the three butterfly trend categories was related to spatially structured climate variables and pure geographical location. However, the relative importance of climate and land cover differed between the butterfly categories. Pure and spatially structured climate variables explained two-fold more variation in species richness in increasing butterflies than in stable and declining butterflies. On the other hand, pure and spatially structured land cover variables explained 2.5–6 times more variation in species richness in declining butterflies than in stable and increasing butterflies. Land cover variables differed in their effects on the species richness of the three trend categories: the amount of grassland had the greatest positive effect on the number of declining species, whereas the amount of forest was the most important land cover variable for species richness of stable butterflies and arable land and field-forest mosaic for species richness of increasing butterflies. The results suggest that habitat availability has the greatest effect on the trends of declining butterfly species, and climate in concert with habitat availability on the trends of increasing species.

The determinants of local species richness of diurnal Lepidoptera were studied in 68 agricultural landscapes in five geographic regions by sampling field margins, road verges, forest edges and patches of semi-natural grassland. Butterflies and day-active moths were counted and habitat quality was measured in 1191 separate 50 m transects. Generalized linear mixed models (GLMM) were built to explain patterns of species richness by first adjusting for the effects of geographic location and weather conditions during the butterfly counts. Habitat type and quality largely determined local species richness, whereas the explanatory power of the local habitat quantity and management variables was limited. Species richness was highest in patches of semi-natural grassland, second highest in forest edges and lowest in road and field margins surrounded by cultivated fields. Species richness increased with abundance of nectar flowers and margin width, and decreased with increasing soil moisture and within-patch openness. Landscape openness showed a unimodal response with a maximum species richness at intermediate values. Largely the same variables affected species richness of moths and butterflies, but moths appeared to be more sensitive to negative effects of windiness and intensive management and less dependent on abundant flowers and increasing margin width than butterflies. The results highlight the significance of even small patches of semi-natural grasslands and open, sunny forest edges for species richness in typical modern farmland with relatively intensive agriculture. The effectiveness of agri-environment schemes in promoting biodiversity could be increased by directing more efforts to maintenance and restoration of these habitats.

This paper compares the performance of five modelling methods in the prediction of a species distribution, using a data set describing the distribution of the threatened clouded apollo butterfly ( Parnassius mnemosyne ) in south-west Finland. The five statistical techniques included were: generalized linear models (GLM), generalized additive models (GAM), classification tree analysis (CTA), neural networks (ANN) and multiple adaptive regression splines (MARS). The accuracy of the models was examined at three spatial resolutions (1, 25 and 100 ha) by area under the curve (AUC) and kappa statistics. All five modelling techniques had a relatively high discrimination capacity for the occurrence of clouded apollo. Classification tree analysis provided the least robust model performance. The differences between the other methods were small, although GAM and MARS provided marginally the best stability and performance. The most accurate models were developed for the resolutions of 1 ha (highest AUC values) and 25 ha (highest kappa values) and the least accurate models for the resolution of 100 ha. Our work shows that modern modelling techniques can provide useful forecasts of species distributions in unsurveyed parts of landscapes and provide valuable contributions to conservation and management planning. However, the success of applying the new modelling tools can be influenced by the choice of statistical technique and especially of spatial resolution. In conclusion, small changes in the spatial scale may result in a clear decrease in the model performance and thus caution should be exercised when implementing the models and their predictions in practice.

The effects of restorative grazing on the abundance of butterfly and moth species were studied in mesic semi-natural grasslands of SW Finland differing in management history: (1) old continuously grazed, (2) restored (with ca 5 years of reinitiated grazing), and (3) abandoned former pastures. Generalized linear modelling of species abundances and indicator species analysis produced qualitatively similar results. Only three species (Polyommatus icarus, Lycaena hippothoe and Camptogramma bilineatum) were most abundant in old pastures, whereas 12 species (Polyommatus semiargus, Polyommatus amandus, Brenthis ino, Aphantopus hyperantus, Scopula immorata, Idaea serpentata, Scotopteryx chenopodiata, Epirrhoe alternata, Cybosia mesomella, Polypogon tentacularius, Hypena proboscidalis and Cryptocala chardinyi) were most abundant in abandoned pastures. None of the old-pasture species had become more abundant in restored pastures. Three species, Epirrhoe hastulata, Xanthorhoe montanata and Chiasmia clathrata, occurred equally abundantly in abandoned and in restored pastures indicating a slow progress of restoration. Species associated with old pastures differed from species associated with abandoned pastures in their recent distributional changes in Finland. The species of old pastures showed decreasing trends, whereas those of abandoned pastures showed mainly increasing trends in their distribution. In five out of 11 species, the preferred successional stage differed markedly between this study and previous studies conducted in Central Europe. We conclude that (1) ca 5 years of restorative grazing in mesic grasslands has been insufficient for the colonisation of old-pasture species in the restored sites, (2) different management intensities are needed regionally for the maintenance of grassland insect diversity and (3) application of the knowledge on successional preferences of different species in conservation management, even in climatically similar regions, should be made with caution.

Bayesian belief network (Fully Connected Belief Networks, FC BeNe) was used to estimate uncertainty in the functioning of established buffer zones in Finland. Four experts in the field of water protection and four in biodiversity were asked to assess the roles of 25 key variables involved in the functioning of buffer zones. The matrix comprised five levels of information: field properties, buffer zone properties, management measures, site data and concerns. The eight experts were asked to estimate probability distributions and causal relationships between the 25 variables, which included in particular erosion, particle bound P, dissolved P, and plant, insect and bird species diversity. Any of the three phases of the analysis; prior distributions, links and posterior distributions are end products which are usable as such. The highest uncertainties were attributed to management measures, e.g. sowing leys, meadow plants, trees and/or bushes and soil removal from the upper end of the field in order to create nutrient-poor meadows. Uncertainties were also seen in P-status, fertilizer and manure changes, transport of dissolved phosphorus, particle bound phosphorus, bird species diversity and landscape. All experts thought that erosion affects particle bound phosphorus, but there was wide deviation in the link strength values, 0.05–0.7, which clearly reflects a lack of knowledge. Two of the experts assumed particle bound P to become partly dissolved, the other two did not. The effect of buffer zones on transport of dissolved phosphorus was not clear. The link strength direction of the variables grazing and rotational grazing to dissolved P varied between the experts. According to the expert evaluations, positive impacts caused by buffer zones were probable in erosion, and in plant and insect species diversity, which is in agreement with existing empirical studies. Experts expected plant height to be beneficial to bird species diversity, but disagreed as to the effect of plant height on plant and insect species diversity. Biodiversity experts considered that steep slopes produced more erosion, more leaching, and hence more patches for biodiversity contrary to water pollution.

A decrease of habitat and species diversity in agricultural landscapes, mainly as a result of the decline of semi-natural grasslands, has been shown in several studies. However, no studies have linked the effects of decrease of grassland management with landscape structure and plant and bird species diversity on the landscape scale in a spatial grid system. In this study we examined the differences in the present habitat and species diversity (number of total and rare plant and bird species) among agricultural landscapes differing in their management history. We compared areas of 0.25 km2 (n = 34) with different grazing history in the Rekijoki river valley, SW Finland. The grazed area decreased to one fifth over 30 years (1960–1990) in our study area. The earlier interconnected network of grazed patches was disrupted, resulting in an isolated grazing pattern. There were statistical differences in the habitat structure and plant species diversity between the landscapes with different management histories, but no difference in bird diversity was observed. The number of rare plant species/0.25 km2 was 45% less in areas of 20–40 years of abandonment compared to squares with continuously grazed patches. The results address the importance of grazing management for maintaining heterogeneous habitat mosaics and plant diversity on the landscape scale.