Organic farms as refuges for small mammal biodiversity in agro ecosystems

Habitat fragmentation, the process by which relatively continuous habitats is broken into smaller pieces, occurs in natural systems but is to a high degree also human-induced through landscape use. Fragmentation of the landscape produces a series of habitat patches surrounded by a matrix of different habitats and land use regimes. The major landscape consequences of fragmentation are loss of habitat, reduction in habitat patch size, and increasing isolation of habitat patches. In general, population performance declines in response to habitat loss but size of remaining area and isolation effects is known also to influence the population trend. Small mammals are well suited for examination of population responses to habitat fragmentation as they have modest spatial requirements and short generation times. In theory, organic farms could play an important role in the agricultural landscape as refuges for some small mammal species, as the lack of pesticide and fertiliser treatment, less weed control, more diversified crop structure and a general environmental friendly attitude, form a basis for habitats that provide cover and food for small mammals, and thus for larger predators of these species. Furthermore, density and area of small biotopes could be expected to be higher in the organic farms, thus leading to a decreased distance between optimal habitats. This study compares species diversity and abundance of small mammals in conventional farms and intensively and extensively grown organic farms. In a wide range of different fields in conventional and organic farms, the diversity and density of small mammals were investigated by live-trapping sessions, comprising trap lines with 15 meters between each trap. We studied the responses of populations (belonging to 11 species of small mammals) to habitat patches of different size and different surrounding management strategies (ecological and conventional farming). We found a general correlation between the number of small mammal individuals and small biotope size. This correlation applies in autumn as well as in spring. There is only a weak tendency for more small mammals in small biotopes within organic farms compared within conventional farms. The number of small mammal species stabilises at small biotope sizes around 1000 square meters. The value of organic farms in respect to small mammal biodiversity depends mainly upon the number and area of small biotopes, and only to a minor degree upon the treatments of the fields

Vole spatial distribution and dispersal in European organic and conventional farming systems

North European landscapes are highly dominated by agriculture, where small biotopes, e.g. meadows, uncultivated grassland, hedge rows, field boundaries, surroundings of water ponds, only comprise a low percentage. In recent years organic farming has expanded in acreage due to customers increased awareness regarding pesticide and fertilizer use and biodiversity conservation. However, organic farming has changed from an extensive production with small fields, low mechanical impact and high crop diversity towards larger fields, intensive mechanical treatment, lower weed densities and lower field diversity. Still, organic farms could play an important, role in the agricultural landscape as refuges for some small mammal species. We studied the responses of populations to habitat patches of different size and different surrounding management strategies (ecological and conventional farming). Studies were performed at two localities in Denmark, Kalø Estate in Eastern Jutland and the Bjerringbro area in Central Jutland. The sampling sites were represented by cultivated grassland habitat, small biotopes within cultivated fields and hedgerows between fields in rotation. Small mammal species assemblages were low in numbers in cultural farmland, and, on a property basis, not significantly different between organic and conventional farms. Very few species and individuals were present in the field matrix, and the small biotopes were by far the most important source of species richness. Species density was positively correlated with the size of the habitat, and, generally, more voles were found in organic habitat patches than in conventional ones. More field voles were found in organic grassland and more bank voles (Myodes glareolus) in organic hedge rows than in conventional ones. Telemetry studies of field voles showed low rates of dispersal and low colonization rates of the more or less isolated small biotopes at the time of year with no vegetation cover in the surrounding fields. We found no significant correlations between distance to nearest stepping stones/dispersal corridors and small mammal densities or species composition. In agricultural areas landscape structure influences the small mammal species living in this fragmented habitat matrix. The value of organic farms in respect to small mammal biodiversity depends mainly upon the number and area of small biotopes, and only to a minor degree upon the management of the fields. This is presumably related to a more dense and diverse vegetation cover, due to a lack of pesticide and fertilizer treatment in the organically managed small biotopes

Texas coastal zone biotopes : an ecography : interim report for the Bay and Estuary Management Program (CRMP)

November 1972Because esthetics, biological environment and physiography are so interrelated and have changeable meanings in various environments, we are obligated to think of the environment in terms of biological change, as environmental protection is presently a basis for much dialogue and sometimes controversy. To do this we have chosen an old concept and adapted it to identify the relationships among biological communities that may be changed when man or nature modifies the coastal environment. The chosen term is BIOTOPE, which is defined in Webster's as a region uniform in environmental conditions and in populations of animals and plants for which it is the habitat. Although the biological environment may appear to the layman as either diverse or uniform and without pattern, there are recognizable biotic assemblages that have some degree of relationship in their composition. Such recognizable assemblages may cover wide areas, such as the extensive turtle grass flats, or may be discrete small units, such as an oyster reef. Thus we have adapted the term BIOTOPE to identify such assemblages and initially suggest the following eighteen examples listed in Table 1. Thirteen of them plus an overview are illustrated. ... If the concept of the BIOTOPE is to be used to describe common, recognizable Texas Gulf coast communities, then we can use these descriptions to demonstrate the results of changes. For example, if one plans to dredge a grass flat to produce a spoil bank and a channel, the Biotopes of these three areas can be compared to allow the decision maker to evaluate how the change may affect the area involved. Because the decision maker is not always scientifically oriented, we have elected to describe the Biotope by artists' renditions accompanied with lists of common and scientific names of major species of plants and animals and a description of the relative productivity of the major organisms in the area.Supported in part by Coastal Resources Management Program, Office of the Governor, IAC (72-73)-806, and The National Science Foundation RANN, Grant GI-34870XMarine Scienc

Limits of stakeholder participation in sustainable development : "where facts are few, experts are many"

Extract from: The Mediterranean coastal areas from watershed to the sea : interactions and changes / by L.F. Cassar ... [et al.]. Proceedings of the MEDCORE International conference, Florence, 10th-14th November 2005The notion of including stakeholders, those affected (positively or negatively) by a sustainable development programme in both its design and implementation, has become a central concern for those implementing such programmes. Such an approach is often referred to as ‘stakeholder participation’, as ‘participatory development’ or more simply still as ‘participation’. How best to achieve this has been the topic of a substantial literature, with a host of different methodologies presented and promoted. Each has its own advantages and disadvantages, but there has been surprisingly little discussion in the sustainable development literature as to the limits and dangers of participation irrespective of the approach employed to ‘best’ facilitate it. Inter-linked with the limits of participation is the role of specialists and expert opinion in sustainable development. This paper discusses the results of participatory exercises conducted in Gozo (Malta) between 2003 and 2005. On the positive side, participation yielded many useful and interesting insights and invoked a sense of ‘involvement’ in sustainable development, but there were problems and these are discussed in this paper. For example, the outcome of the exercise crucially depends upon representation, and a simplified vision of ‘community’ often employed in participation to make it practicable can load the process in favour of certain stakeholder groups at the expense of others.peer-reviewe

Organic Farming - Nature Conceptions, Management and Cross Compliance

Organic farmers perceptions of qualities in nature do not clearly correspond with the biologists ideas of nature quality. The differences in perception hold both opportunities and conflicts

New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg

<b>Background</b><p></p> The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg.<p></p> <b>Methods</b><p></p> During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n = 2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n = 4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex® technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500–600 bp) (acting as an internal control) and a 124 bp fragment of repetitive DNA from Fasciola sp.<p></p> <b>Results</b><p></p> Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle.<p></p> <b>Conclusions</b><p></p> Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed

Indicators of resource use and environmental impact for use in a decision aid for Danish livestock farmers

Farmers lack well documented sets of farm level indicators to allow their own evaluation of environmental impact and to stimulate the development of more environment friendly farming practices. A set of farm level indicators of resource use and environmental impact on livestock farms was developed as part of a decision aid for farmers. The indicators were meant to be part of an extended farm account and included the surpluses and efficiencies of N, P and Cu, the energy use per kg grain and per kg milk or meat, pesticide treatment index (TFI), % unsprayed area, % small biotopes on the farm, and % weeds in grain crops. The indicators were tested on 20 Danish dairy and pig farms over a period of 3 years in order to see if they were suitable for use in the farmer’s management. The third year, farm gate surpluses varied between 89 and 265 kg N ha−1, 2 and 31 kg P ha−1 and 0.1 and 0.8 kg Cu ha−1. Energy use varied between 2.1 and 4.1 MJ kg−1 milk and between 14 and 20 MJ kg−1 live weight pig sold. For all indicators, except energy use per kg grain, the variation in indicator levels between farms was more important than the variation between years within each farm. There was significant variation between farms after correction for stocking rates and soil-and farm types, which suggests that the indicators reflect differences in management practise on comparable farms. It was demonstrated that these differences between similar farms and between the years on the individual farms might be explained by the detailed knowledge of management of the farms’ different subsystems (herd and crops). The information given by the indicators is discussed from environmental and management points of view and problems of defining and interpreting the indicators are identified. Given further development of indicators for soil quality and nature values, the farm level indicators seem a promising way of enabling farmers to include environmental topics in their management

ORGANIC FARMS AS REFUGES FOR SMALL MAMMAL BIODIVERSITY

Habitat fragmentation, the process by which relatively continuous habitats is broken into smaller pieces, occurs in natural systems but is to a high degree also human- induced through landscape use. Fragmentation of the landscape produces a series of habitat patches surrounded by a matrix of different habitats and/or land use regimes. The major landscape consequences of fragmentation are loss of habitat, reduction in habitat patch size, and increasing isolation of habitat patches. In general, population performance declines in response to habitat loss but size of remaining area and isolation effects is known also to influence the population trend. Small mammals are well suited for examination of population responses to habitat fragmentation as they have modest spatial requirements and short generation times. In theory, organic farms could play an important role in the agricultural landscape as refuges for some small mammal species, as the lack of pesticide and fertiliser treatment, less weed control, more diversified crop structure and a general environmentalfriendly attitude, form a basis for habitats that provide cover and food for small mammals, and thus for larger predators of these species. Furthermore, density and area of small biotopes could be expected to be higher in the organic farms, thus leading to a decreased distance between optimal habitats

Nature quality in organic farming: A conceptual analysis of considerations and criteria in a European context

Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape. The present paper looks at nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the "Ecologist View of Nature". This is in contrast to the "Culturist View" characteristic of much conventional agriculture and the "Naturalist View" characteristic of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we will explore how criteria for nature quality based on the Ecologist View can be developed and thereby feed into the ongoing discussion of the development of the organic farming practises. We suggest additional criteria for nature quality based on an Ecologist View of Nature: biodiversity; habitat diversity, extent and structure; functional integrity of habitats and agroecosystems; and landscape integrity, accessibility and experientiality. The larger set of Naturalist and Ecologist criteria can provide a wider and more balanced basis for developing nature quality indicators that are relevant in the farmed landscapes. This broader approach to nature quality is also expected to benefit the general societal discussions and decisions on farming and nature