production, biodiversity and ecological connectivity
3.10 Agriculture and ecological connectivity
3.10.2 What do ecological networks mean in agricultural areas?
Ecological networks provide for several functions in the maintenance of the health of the environ-ment. They enable the conservation of biodiversity at
ecosystem and regional scales, putting an emphasis on the reinforcement of ecological coherence and con-tinuum and integrating biodiversity conservation into broad environmental management plans. Ecological networks may buffer critical areas from the effects of potentially damaging activities and help in the restora-tion of degraded ecosystems. Ensuring the ecological continuum, without limiting human development, con-tributes to the promotion of sustainable use of natural resources and to the raising of people’s awareness in respect to a pacific coexistence and sharing of common spaces with wildlife species (Favilli et al., 2013, 2015).
Ecological networks can greatly contribute to the maintenance or the protection of the biodiversity of agricultural areas. Ecological networks connect areas of habitat and allow animals and plants to move through the countryside. This potential for free movements is an important factor for the survival of many species in relation to changes in land use patterns and climate. As well as being vital for the functioning of ecosystems, ecological networks and corridors, greenways and landscape linkages also have aesthetic value that may contribute to increasing the attractiveness of living and working environments. Ecological networks are not only for wildlife species. They may have important rec-reational and touristic value and can offer further eco-nomic benefits by protecting property and businesses
Agricultural landscape in the Nature Park Kaunergrat.
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from environmental impacts or providing a source of food, fuel and building materials (Ailte et al., 2007).
Farming may have a crucial impact on biodiversity in the Alps that can be either negative or positive. On one hand, intensive agriculture in valleys is a major obstacle to the migration of fauna and the spread of wild plants.
On the other hand, extensively farmed high fields can still be of outstanding biodiversity value, although the abandonment of traditional farming practices increas-ingly threatens these fields. In intensively worked fields, for example, connectivity can be enhanced through green margins or structural linear elements like hedges and dry-stone walls. Extensive forms of management, without the use of fertilisers or insecticides, for ex-ample, help to maintain biodiversity and ecological networks and can enhance control of weeds, diseases, and arthropod pests and increase pollination services.
Furthermore, they increase soil quality, carbon seques-tration, and water-holding capacity in surface soils, energy-use efficiency, and resistance and resilience to climate change (Kremer and Miles, 2012).
The general public should be aware of what farmers can do to promote connectivity, and to protect the high socioeconomic value of the ecosystem services that rural and mountain areas provide. Farmers should receive appropriate compensation for this contribu-tion, because these measures are helping to conserve biodiversity as a basis for life and to create an attractive living environment for the whole of society (Kohler and Heinrichs, 2011).
Many environmental improvements (Genghini, 1994) can play a key role in the maintenance of the struc-tural and functional connectivity of the landscape.
Different species can use them as seasonal refuges and/or core areas and, therefore, these improve-ments are extremely useful for the survival of biodi-versity. Agricultural landscapes can also contribute positively to the establishment and maintenance of ecological connectivity. Small linear features such as hedgerows, field margins, verges, or remnants of semi- margins, help to enhance diversification of the environment (Figure 14).
// Figure 14: The illustration depicts a farmed landscape in which connectivity is high. It contains many features that are desirable for wildlife but which can also contribute to farming practice and game management
Wooded hilltop
Hedgerows and
embank-the water
Shelters wildlife and game Protects crops (wind-break) and
slows the movement of water
and preserves the banks
Source: Adapted from Bonnin et al., 2007
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Interventions that can be made by farmers and land managers to support ecological corridors in the territo-ries of their competencies (CIPRA, 2010) range from the restoration or maintenance of landscape elements to a wider landscape management scheme. Single measures have to be inserted into a strategy combining the crea-tion of an ecological network with the maintenance of traditional agriculture.
These single measures usually take the form of strips of vegetation that have been deliberately planted for a variety of purposes including: shelter, reduction of soil erosion, provision of timber sources, creation of wild-life habitat or for aesthetic qualities. The agricultural field margins not only provide a habitat for rare species of plants and contribute to the protection of soils and water resources, they also constitute important linear transit routes and form buffer zones between vari-ous forms of land use. Along fields and paths, the field margins form a network of linear connecting elements.
Inclusion of these areas in local plans increases this positive impact significantly.
The new structural elements display great variation in origin, floristic composition and structure, but there are several common features:
→ They are linear (but not always straight) and usually form grid-like networks of habitat
→ They frequently provide links between remaining natural and semi-natural habitats
→ They are closely associated with agricultural land, since past and present agricultural land manage-ment strongly influence their composition and structure.
They take forms such as:
→ Hedgerows: linear strips of shrubs, small and some-times large trees planted along the boundaries of fields, roadways, fences and other no-cropped areas.
→ Stone walls: replacement for hedges, particularly in upland and arid areas, where shrubs do not grow so well.
→ Fencerows: narrow strips of rough land that have developed by the natural regeneration of plants in neglected strips of land between fields, by roads and water bodies. Their vegetation ranges from that
dominated by grasses and herbs, to narrow lines of shrubs, to broad strips with mature woodland trees.
→ Wind-breaks: barriers usually consisting of trees or shrubs that are used to reduce and redirect wind.
→ Filter strips: areas planted with vegetation to con-trol soil erosion; they slow down water runoff and capture and prevent sediments and nutrients from entering waterways.
They are used:
→ As nesting, roosting and feeding habitat, and cover by forest-edge, farmland and game birds and sig-nificantly increase their number and diversity
→ By mammals, amphibians and reptiles as breeding areas, shelter, temporary refuge, or foraging habitat (species include badger and fox, small mammals such as field mice and bank voles, and amphibians)
→ By insects to gain nectar and pollen, prey and shel-ter (this includes ladybugs, hover flies, ladybird beetles, green and brown lacewings, parasitic and predatory wasps and spiders – many of them ben-eficial to agriculture as natural pest control agents).
Nevertheless, these particular landscape and agricultural structures are negatively impacted by herbicides, pesti-cides or manure through leaching and transport by soil water or airborne deposition from adjacent fields. At the landscape level, the removal of linear elements, such as hedges and walls, is of great importance. This is a slow process mainly driven by changes in the agricultural system. Crops, in contrast, vary more rapidly on a yearly basis (Burel, 2002). On one hand, many species have grown accustomed to extensive agricultural systems, since these systems include small features that can help animals in their basic need for movement; on the other hand, certain species have also adapted to some inten-sively managed areas (for example wet grasslands, wet areas with rice cultivation). Examples include breeding and wintering water birds in the Netherlands, Belgium and northern Germany, and species (for example badg-ers, certain birds) of hedgerow landscapes in France, UK and Ireland (Hoffmann, 2001).
All of these structural elements need to be managed with care. Where they are absent, these features can be created. In many areas of Europe financial subsidies and advice, written or in the form of farm
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conservation advisers who are able to visit farms and even create wildlife management plans, are available to farmers and land managers. This can be focused on both the ongoing management of habi-tats and features that provide connectivity, as well as on the creation of new areas for wildlife. Other measures that can be carried out in agricultural fields to improve ecological connectivity include (Kohler and Heinrichs, 2011):
Land set-aside: Areas of wild herbs on agricultural fields provide important areas for resting, breeding, feeding, mating or cover. Set-aside areas distributed across the agricultural landscape can create high-quality habitats for wild fauna and flora and thus con-tribute on a sustainable basis to the conservation of characteristic communities in open farmland.
Fallow areas act as stepping stone biotopes. Their in-clusion in local spatial planning greatly increase their positive impact
Extensive use of grasslands and organic farming:
Extensively used grasslands are extremely important for the biotope network due to their species richness.
Their extensive use with zero to moderate fertilization, no use of plant protection products, no ploughing up of grassland or sowing, and low frequency of cutting and specific mowing techniques can also help to im-prove biotope functions. The impact on an ecological network is increased if individual areas are integrated into a network of extensively used margins and scat-tered dry meadows. Organic farming has an extremely important role to play; one reason being that it avoids and reduces the environmental stresses that can other-wise arise in farming. Furthermore, the targeted crea-tion of landscape elements, ecological compensacrea-tion areas such as hedgerows, fallow areas, forest strips and extensive meadows make an important contribution towards the promotion of biological diversity.
Species-rich seeding on agricultural fields: Species-rich seeding of wild and cultivated plants on set-aside or
Structure rich rural landscape in the Mercantour National Park in France.
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“green” areas created in compensation for natural spaces lost through construction of roads or fallow land in resi-dential areas can enrich the landscape’s appearance and make a valuable contribution to the biotope network.
Seeding with wild species provides a source of food and cover for wild fauna and, depending on the mix of seeds used, can also provide habitats for insects.
Maintenance and preservation of mixed orchards:
Mixed orchards are a characteristic and attractive fea-ture of the cultural landscape in many Alpine regions and are among the most valuable patch biotopes. The structural diversity in mixed orchards and the result-ing diverse mosaic-type habitats provide a habitat for a wide range of species of flora and fauna. In inten-sively used agricultural landscapes, they constitute important connective structures in the local biotope network. The conservation measures for these areas must include arrangements for mowing, fertilising, management and maintenance, the preservation of ageing trees and more.
Encouragement of unpaved paths: Depending on their type and the way in which they are built, paths can have a low to high barrier effect. Pathway systems and their peripheral areas do not necessarily have a fragmenting effect on all species of flora and fauna, and if properly designed, they can also form important elements of the biotope network. They provide routes through the landscape and form buffer zones to inten-sively farmed areas.
Additional measures can include the maintenance and restoration of traditional irrigation systems, the pro-motion of traditional pasturing with sheep cultivation areas in a sustainable way, the maintenance of open areas by controlled burning, and tree maintenance and preservation of pollarded trees.
3.10.3 Conclusions
Models and policies often focus either on landscape design (that is implementation of corridors) or land use practices (that is less pesticide), while sound man-agement needs to combine both. The main reason is that corridor quality is not independent of adjacent land use (Le Coeur et al. 2002), and that solely chang-ing practices is not enough in providchang-ing new land-scape elements, especially perennial ones (strip of grass, hedgerows). The territorial policies, particularly with regard to biodiversity and to conservation of biological and extensive agriculture and of local prod-ucts, are often used only as an opportunity for politi-cal propaganda, without being integrated in to a strat-egy that requires actions (and funding) that are imme-diately available yet persistent in the long-term. It is therefore fundamental to see processes as composite and not only punctualted and simple. These processes must include a bottom-up phase. The different ac-tors must employ multiple modalities and address a variety of issues. They must operate on the basis of a solid and informed technical/scientific background in order to manage integrated actions for larger spaces.
This warrants the creation of governance processes inspired by real problems within the territory and capable of amending decisions taken in haste.
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Since 2007, this Initiative has offered an open forum for developing joint strategies and actions concerning ecological connectivtiy primarily in the Alpine area and beyond. The Continuum Initiative aims to create a common Alps-wide framework for transboundary and trans-sectoral cooperation in order to raise awareness for logical connectivity and to protect or restore eco-logical networks linking flora and fauna habitats and protected areas.
The Initiative focuses on three targets:
1. Initiating, promoting and mentoring activi-ties: The Initiative`s work and commitment have led to the establishment of the Ecological Network Platform of the Alpine Convention and the initiation of the EU Alpine Space project ECONNECT. Since 2010, the Contin-uum Initiative has gathered a large number of experts in a think tank.
2. Providing know-how: The initiative provides a website with a catalogue of measures for
improving ecological connectivity and a data-base of publications, research projects, and ex-perts from research and practice:
www.alpine-ecological-network.org
3. Awareness-building: The Initiative organises communication campaigns addressing differ-ent target audiences via a series of ten factsheets on the integration of connectivity into land use practices, such as: the film “For hermits and fire salamanders”7 in order to raise awareness for connectivity among municipalities, and the campaign “The Wall”, placed in pedestrian areas of large cities as Milan, Zurich or Munich.
The Ecological Continuum Initiative has been pro-moted by the Alpine Network of Protected Areas (ALPARC), the International Commission for the Protection of the Alps (CIPRA), the WWF Alpine Programme, and the International Scientific Com-mittee for Alpine Research (ISCAR). These organisa-tions have been collaborating on this issue since 2002, and their work has been partly funded by the Swiss MAVA Foundation for Nature.