Landscape heterogeneity as an ecological filter of species traits

International audienceLandscape heterogeneity is a major driver of biodiversity in agricultural areas and represents an important parameter in conservation strategies. However, most landscape ecology studies measure gamma diversity of a single habitat type, despite the assessment of multiple habitats at a landscape scale being more appropriate. This study aimed to determine the effects of landscape composition and spatial configuration on life-history trait distribution in carabid beetle and herbaceous plant communities. Here, we assessed the gamma diversity of carabid beetles and plants by sampling three dominant habitats (woody habitats, grasslands and crops) across 20 landscapes in western France. RLQ and Fourth Corner three-table analyses were used to assess the association of dispersal, phenology, reproduction and trophic level traits with landscape characteristics. Landscape composition and configuration were both significant in explaining functional composition. Carabid beetles and plants showed similar response regarding phenology, i.e. open landscapes were associated with earlier breeding species. Carabid beetle dispersal traits exhibited the strongest relationship with landscape structure; for instance, large and apterous species preferentially inhabited woody landscapes, whereas small and macropterous species preferentially inhabited open landscapes. Heavy seeded plant species dominated in intensified agricultural landscapes (high % crops), possibly due to the removal of weeds (which are usually lightweight seeded species). The results of this study emphasise the roles of landscape composition and configuration as ecological filters and the importance of preserving a range of landscape types to maintain functional biodiversity at regional scales

The legacy of 20th Century landscape change on today’s woodland carabid communities

Aim For many species, the effects of landscape change can involve a time lag and result in an extinction debt. The landscape matrix plays a vital role in supporting species populations. However, the importance of the historical composition and configuration of landscape mosaics has received little attention, with studies focusing on the effects of loss and fragmentation of single (focal) habitat over time. We investigated the importance of historical and contemporary landscape heterogeneity (composition and configuration) to identify how landscape change has, and is continuing to have, an effect on current woodland carabid communities. Location Lowland Britain. Methods Carabids were sampled from woodlands in 36 tetrads of 4 km2. Ordination methods analysed current community response to representations of contemporary and historical (1930’s) landscape heterogeneity. The effects of 80 years of landscape change on current carabid assemblages were compared among tetrads. Results Results are consistent with an extinction debt; carabid communities correlated significantly with the historical composition and configuration of the landscape, but not contemporary landscape configuration. Community assemblages have been shaped, and many species remain affiliated with landscape conditions that no longer exist, notably, large patches of broadleaf woodland and semi-natural grassland. Recent introduction of conifer plantations has had a negative effect on the abundance of many woodland species. For many common, slow-dispersing species, contemporary and historical landscapes offered sub-optimum woodland coverage indicating a lag effect that exceeds 80 years. Increased arable landcover and loss of semi-natural grassland and heathland points towards an ongoing detrimental impact on carabid populations. Main conclusions Compared with focal-habitat studies, the landscape mosaic approach provides a more comprehensive understanding of the effects of widespread landscape change on species communities. Conservation guidance includes new planting, maintenance and restoration of semi-natural habitats, implemented across multiple spatial scales and where feasible, considering both historical and contemporary landscape heterogeneity

Landscape Agroecology and ecosystem services

Landscape Agroecology and ecosystem service

Aider à la gestion des services de régulation naturelle des bioagresseurs : enjeux de connaissances et de prise en compte des agriculteurs : une approche bibliographique

Comment construire des connaissances pour aider les agriculteurs à mieux mobiliser les services de régulation naturelle des bioagresseurs? Nous avons réalisé une revue de la littérature scientifique pour examiner si et comment les connaissances produites pouvaient aider à la réalisation d'un diagnostic de ces services. Nous avons considéré pour cela que ces connaissances devaient porter sur les relations entre i) la problématique de la régulation naturelle des bioagresseurs, ii) les facteurs affectant cette problématique (e.g., pratiques agricoles, environnement paysager), et iii) les ressources des agriculteurs impactées par la régulation biologique (e.g., productions) et/ou permettant de maîtriser les facteurs affectant cette régulation (e.g., ressources en connaissance, travail, équipements). Nous avons aussi examiné si les dynamiques temporelles de ces relations étaient étudiées (Duru, Therond et al, 2015). 1. Nous avons réalisé une requête large dans le Web Of Science des études portant sur le contrôle, y compris chimique et/ou mécanique, des bioagresseurs (15334 articles). 2. Ayant peu de mots clés précis pour identifier les dimensions d'un diagnostic dans ces études, nous avons construit et mobilisé des dictionnaires de mots clés dans une analyse lexicale de notices avec l'outil CorText. Un sous-corpus de 6024 articles a été obtenu après extraction d'études hors-sujet. Nous avons identifié 9 thématiques diversement combinées dans les études, les plus fréquentes étant: "gestion des bioagresseurs", "gestion des adventices", "systèmes de cultures", "modélisation et prise de décision", "acteurs et système d'exploitation" et "agroécosystème et paysage". 3. Afin d'identifier les connaissances utiles pour un diagnostic à partir de ces thématiques, nous avons échantillonné des études selon leurs profils et les avons analysées à partir d'une grille de lecture ad hoc. Nous présentons les résultats pour une sélection de 31 études les plus pertinentes a priori. Leurs notices mentionnent la régulation naturelle des bioagresseurs et combinent 3-5 thématiques dont au moins "acteurs et systèmes d'exploitation": notre hypothèse est qu'elles prennent en compte explicitement les acteurs et leurs ressources. Ces études sont effectivement les plus riches. Cependant la plupart n'étudient aucune dynamique temporelle. Nous avons distingué 3 groupes. Le premier groupe (15 articles) met l'accent sur l'élucidation de l'influence relative des facteurs "pratiques" et "paysage" sur le phénomène de régulation; les ressources des agriculteurs sont contextuelles (ex: comparaison agriculture biologique vs. agriculture conventionnelle). Le deuxième groupe (6 articles) met l'accent sur l'impact de la régulation biologique et/ou des nouvelles pratiques et aménagements paysagers sur les ressources des agriculteurs (e.g., coûts/bénéfices économiques) à l'échelle de la parcelle. Le dernier groupe (10 articles) est le plus intégrateur des composantes du diagnostic; on y trouve le plus d'études engagée dans l'accompagnement des agriculteurs, notamment l'apprentissage collectif (Bell et al, 2016; Robertson et al, 2014)

Agroforestry systems of high nature and cultural value in Europe: provision of commercial goods and other ecosystem services

Land use systems that integrate woody vegetation with livestock and/or crops and are recognised for their biodiversity and cultural importance can be termed high nature and cultural value (HNCV) agroforestry. In this review, based on the literature and stakeholder knowledge, we describe the structure, components and management practices of ten contrasting HNCV agroforestry systems distributed across five European bioclimatic regions. We also compile and categorize the ecosystem services provided by these agroforestry systems, following the Common International Classification of Ecosystem Services. HNCV agroforestry in Europe generally enhances biodiversity and regulating ecosystem services relative to conventional agriculture and forestry. These systems can reduce fire risk, compared to conventional forestry, and can increase carbon sequestration, moderate the microclimate, and reduce soil erosion and nutrient leaching compared to conventional agriculture. However, some of the evidence is location specific and a better geographical coverage is needed to generalize patterns at broader scales. Although some traditional practices and products have been abandoned, many of the studied systems continue to provide multiple woody and non-woody plant products and high-quality food from livestock and game. Some of the cultural value of these systems can also be captured through tourism and local events. However there remains a continual challenge for farmers, landowners and society to fully translate the positive social and environmental impacts of HNCV agroforestry into market prices for the products and services

Diversity Of Wheat Crop Management From Conventional To Organic Farming: Socio-Economic And Ecological Assessment.

" Biological control is considered a promising way to reduce pesticide use in cropping systems. In this study we aimed to assess biological control and natural enemy communities in a diversity of organic and conventional wheat fields. We also aimed to evaluate economic and labor aspects of cropping systems studied. Twenty pairs of organic and conventional fields were studied in Brittany, France in 2016. Data on carabid abundance and species richness, as well as pest predation rates were collected in fields; crop management and machinery used were also surveyed. We identified 2 organic crop management types and 3 conventional types. Results were not equal for all types of each category. One type of organic crop management, associated with less work for farmers and more economic profit, was beneficial to carabid beetles. Predation rate was lower only in one type of conventional crop management compared with other management types. This study underlines the need to account for the diversity of crop management strategies to assess socio-economic and ecological aspects in organic and conventional farming systems.

Agroforestry systems of high natural and cultural value in Europe: structure, management, goods and services

info:eu-repo/semantics/publishedVersio

Agroforestry is paying off – Economic evaluation of ecosystem services in European landscapes with and without agroforestry systems

The study assessed the economic performance of marketable ecosystem services (ES) (biomass production) and non-marketable ecosystem services and dis-services (groundwater, nutrient loss, soil loss, carbon sequestration, pollination deficit) in 11 contrasting European landscapes dominated by agroforestry land use compared to business as usual agricultural practice. The productivity and profitability of the farming activities and the associated ES were quantified using environmental modelling and economic valuation. After accounting for labour and machinery costs the financial value of the outputs of Mediterranean agroforestry systems tended to be greater than the corresponding agricultural system; but in Atlantic and Continental regions the agricultural system tended to be more profitable. However, when economic values for the associated ES were included, the relative profitability of agroforestry increased. Agroforestry landscapes: (i) were associated to reduced externalities of pollution from nutrient and soil losses, and (ii) generated additional benefits from carbon capture and storage and thus generated an overall higher economic gain. Our findings underline how a market system that includes the values of broader ES would result in land use change favouring multifunctional agroforestry. Imposing penalties for dis-services or payments for services would reflect their real world prices and would make agroforestry a more financially profitable system

Evaluation der Ökomassnahmen: Bereich Biodiversität

1993 führte der Bund ökologische Direktzahlungen ein; seit 1999 ist die Erbringung des ökologischen Leistungsnachweises (ÖLN) durch die Landwirtschaftsbetriebe die Voraussetzung zum Bezug von Direktzahlungen. Heute werden 97 % der landwirtschaftlichen Nutzfläche nach den Regeln des ÖLN bewirtschaftet. Die wichtigste Massnahme des ÖLN, welche einen Einfluss auf die Biodiversität hat, ist, dass die Betriebe 7 % ihrer landwirtschaftlichen Nutzfläche (LN) als ökologische Ausgleichsflächen (öAF) auszuweisen haben (bei Spezialkulturen 3,5 %). Weitere Anforderungen des ÖLN (ausgeglichene Nährstoffbilanz, geregelte Fruchtfolge, Bodenschutz, gezielter Einsatz von Pflanzenschutzmitteln, tiergerechte Haltung der Nutztiere) können ebenfalls einen Einfluss haben, stehen jedoch weniger im Vordergrund

Butterfly richness and abundance in flower strips and field margins: the role of local habitat quality and landscape context

Flower strips, which are created on arable land by sowing species-rich seed mixtures, are considered to have a high potential to counteract species decline of butterflies in the agricultural landscape. However, it remains largely unexplored how various factors (design, habitat quality, landscape context)interact to determine the occurrence of butterflies in flower strips. Therefore, butterflies were surveyed in 15 flower strips differing in age (first and second growing season). Flower strips were compared with 15 field margins, which were adjacent to arable land and were dominated by grasses. The field studies were conducted during two summers (2013, 2014)in Lower Saxony (Germany). Additionally, based on a literature study, 17 environmental variables likely to be decisive for the occurrence of butterflies were identified and recorded during these field studies or analyzed in GIS. Supported by a PCA, 8 environmental variables for flower strips and 7 for field margins, were selected and included in linear mixed-effects models in order to calculate their effect on butterflies. We documented 19 butterfly species and 1,394 individuals in the flower strips and 13 species and 401 individuals in the field margins. The number of flowering plant species was the key factor for the occurrence of butterflies - both in flower strips and field margins. The diversity of the surrounding landscape (Shannon-Index H)had an additional significant influence on butterflies in flower strips, with more species and individuals being observed on areas with a lower Shannon-Index. Number of flowering plant species is the key driver of butterfly diversity and abundance, which improves the habitat quality of flower strips in agricultural landscapes. In order to promote butterflies optimally, flower strips must have a good supply of flowers even over several years. This requires careful design and management, as flower supply often decreases with increasing age of the flower strips. The study indicates that flower strips have a particularly high effect in structurally simple landscapes