Restoration of agro-biodiversity in Switzerland

Transcription

1 Restoration of agro-biodiversity in Switzerland I Swiss Federal Research Station for Agroecology and Agriculture, Zurich, Switzerland 2 Research Institute of Organic Agriculture, Frick, Switzerland 3 Department of Environmental Science, University of Zurich, Switzerland Abstract In 1995 the Swiss people voted a constitutional article which tied agricultural subsidies to ecological requirements. Among other measures, farmers had to convert at least 7 % of their land to semi-natural biotopes (ecological compensation areas - ECA). Major ECA are extensified grassland, traditional orchards, hedges, wild flower strips. The introduction of ECA throughout the country's agricultural area can be seen as a large scale landscape restoration experiment. Its biological effects are evaluated in a monitoring programme. Preliminary results show that endangered plant species are present on 42 % of 582 meadows examined in 1999, making up 29 % of the 486 plant species recorded. Positive effects of ECA were recorded also with respect to butterflies, carabid beetles, and spiders. From the "political-willingness-to-pay" a monetary value can be calculated as a measure of the importance which the population attaches to the biodiversity of agricultural landscapes. l Introduction In the early 1990s the growing costs for the regulation of agricultural markets and increased awareness of environmental damage caused by agriculture led to the introduction of agri-environmental programmes in Europe. In the European Union (EU), they were based on regulation 2078/92, now integrated into which set the framework for national or regional schemes. In Switzerland, although not a member country of the EU, there was a similar development. From 1993 onwards, farmers had to increasingly provide ecological

2 services in order to qualify for direct payments and additional incentives were given for specific measures. Basically, the Swiss agri-environmental policy can be regarded as complementary to the European approach. There are, however, some particular features: - the Swiss agri-environmental policy was repeatedly sanctioned by public referenda, - the farmer participation is particularly high, - the utilised agricultural area (UAA) of the entire country has been interspersed with ecological compensation areas (ECA). The pillars of the Swiss agri-environmental programme consist of strong incentives for integrated production (aiming mainly at a reduction of nutrients and pesticides in soils and waterbodies), of incentives for animal husbandry (aiming at increased animal health and wellbeing) and on the introduction of ECA. The main purpose of ECA is to stabilise and enhance agro-biodiversity. In this contribution, the ECA-scheme and its adoption by farmers is presented (Section 2), some preliminary effects of the scheme on agro-biodiversity are summarised (Section 3), an approach for the monetary valuation of agro-biodiversity based on political-willingness-to-pay is outlined (Section 4) and the further development of the Swiss agri-environmental policy is sketched (Section 5). 2 Ecological compensation areas (ECA) About half of the total land area in Europe is under agricultural use and agriculture has a key responsibility for the preservation of biodiversity on the continent [l]. There are basically two distinct approaches to the conservation of agrobiodiversity: - the concentration of measures and funds on particularly valuable (from an environmental point of view) and sensitive areas with the achievement of high environmental standards in those areas but only very few restrictions on agricultural production in the rest of the UAA; - the spreading of measures and fimds on as many regions and farms as possible to achieve minimum ecological standards on the entire territory. In Europe, all intermediate stages between those two approaches can be found in the about 150 agri-environmental programmes which exist [2]. The goal of the ECA scheme in Switzerland is [3]: - to enhance natural biodiversity, - to preserve agro-biodiversity (no further extinctions but stabilisation and spreading of endangered species). This can only be achieved by an approach aiming at the entire UAA. The Swiss agri-environmental programme therefore requires that each participating farmer has to convert 7 % of his or her farmland to ECA. The catalogue of ECA encompasses traditional landscape elements as well as new types of biotopes which were designed for the purpose of enriching the agricultural landscape (Table 1). The management of ECA is regulated in order to achieve environmental goals (restrictions in fertilisation, pesticide use, prescribed dates for mowing of meadows, etc.). Agricultural management must be continued (no

3 abandonment). For most types of ECA farmers have to commit themselves for at least 6 years. Table 1. Major types of ecological compensation areas in Switzerland. Source: L41 ECA types Surface in 1999 hectares Traditional ECA types Low intensity meadows, litter areas: Grassland with minimum size of ha, restrictions on fertilisation and mowing, commitment for 2 6 years Traditional orchards: Standard fruit and nut trees, mostly on grassland 24632' Hedges, field and riverside woods: Hedges with grassland buffers of 2283 >3 m on both sides, total area 2 5 ares, commitment for 6 years or more Others: low intensity pastures, single trees and alleys, wooded pastures, n.a. water ditches and ponds, ruderal areas, stonewalls, naturally covered field tracks, species rich vineyards Novel ECA types Wild flower strips: Arable fallow sown with seed mixtures of wild plants, m width or more, no fertilisers or pesticides. Short term rotational fallow is also possible. Low intensity cropping strips: Strips (3-12 m) of extensively managed 59 cereals, rape, sunflowers, leguminoses; no fertilisation, restricted pesticide use, in two consecutive years at the lame location. l Estimated from the number of trees, assuming 0.01 hectaresltree Almost 80 % of the UAA in Switzerland is grassland [5], this is reflected by the high share of grassland-type ECA (75 % of total ECA area). In comparison, the other types are far less important in area. Still, in regions where arable agriculture dominates, linear landscape elements (strips with annual or perennial vegetation) are important elements of ecological infrastructure [6, 71. The Swiss agricultural sector mainly consists of relatively small family farms (average farm size 18.4 hectares in 1999 [g]) and because the acceptance of the ECA-scheme is almost general (90.05 % of farmers in 1999 farming 94.9 % of UAA [g]), ECA are distributed throughout the UAA of the entire country. There is, however, an increased share of ECA in mountain regions, where 14.3 %of the UAA is managed as ECA as compared to the intermediate hilly zone (7.1 %) and the lowlands (6.7 %). 3 Effects of ecological compensation areas on agricultural biodiversity An evaluation programme was launched in 1996 in order to assess the effect of the agri-environmental policy. The status of agro-biodiversity is assessed by means of indicator groups: vascular plants, carabid beetles, spiders, butterflies, grasshoppers, breeding birds. The indicators are supposed to react specifically to the landscape change imposed by the ECA scheme. They meet general criteria for biodiversity indicators (e.g. [10]) such as stable taxonomy, occurrence in a

4 breadth of habitats, a broad geographical range, etc., represent all major functional guilds and take into account several spatial and temporal scales. At a large scale, the evolution of the vegetation of ECA and of breeding birds of the Swiss Plateau is followed. Because an eventual observation of a change in biodiversity cannot be assigned to the agri-environmental scheme (other factors interfere such as modifications of agricultural practices caused by market forces, nature protection policies, climate change, etc.), in three case study areas of about 5 sqkm each the causal relationships between the introduction of ECAs and biodiversity indicators are investigated. The research will continue until 2005 and a concluding evaluation will only then be possible. Some preliminary results are nevertheless summarised below. They concentrate on some of the most prominent ECA-types (meadows, wild flower strips) and on the landscape as a whole. 3.1 ECA grassland By far the largest share of ECA are different types of grassland: extensively managed meadows (no or only minor fertilisation, first cut not before June and even later in mountain areas), litter meadows (no fertilisation, mown not before September l"', not more than once per year but at least once every three years), extensively managed pastures (no fertilisation, regular pasturing). Whereas some meadows are very precious from a nature protection point of view, most ECA meadows consist mainly of grasses and herbs which are typical for (formerly) intensively managed mown grassland such as Lolium spp., Dactylis glomerata, Ranunculus spp., Taraxacurn officinale, Poa trivialis, etc. [l l]. Still, e~~dangered species occur as well. In 582 relevces in the Swiss plateau 486 vascular plant species were found. Of these, 101 can be considered "extinct in the wild" or "critically endangered" or "endangered" or "vulnerable" or "threatened at lower risk" according to Landolt [12]. Most of them, however, were present in less than 1 % of the meadows. Species which are typical for traditional hay meadows of the lowlands (e.g. Arrhenatherum elatius, Plantago lanceolata, Festuca spp, Centaurea jacea, etc.) were more frequent [13]. Based on these species, assessment tools will be developed to judge the botanical quality of ECA meadows. Spider populations have been compared between ECA meadows and non- ECA meadows. In one of the case study regions, about 16'000 spiders of 135 species have been trapped (funnel pitfall traps). Species numbers were around 20 in both, ECA and non-eca meadows. Species composition differed between the two groups of meadows as revealed by canonical correspondence analysis (Figure 1). In conclusion, ECA-meadows are habitats for spiders which otherwise cannot be found in the agricultural landscape.

5 Non-ECA meadows (n= 1 5 ) ECA meadows (n=: 13) LISP, Spiders Figure 1: Ordination of the canonical correspondence analysis of spider populations in ECA and non-eca meadows. Assemblages of the two types of meadows differ significantly (p=0.05, Monte Carlo permutation test). Source: [l Wild flower strips Wild flower strips are arable fallows sown with seed mixtures of wild- plants which are commercially available. The strips must 3 m wide or more, fertiliser or pesticide applications are not allowed. Cutting the vegetation is allowed once a year on half of the surface from the second year on to avoid invasion of woody species and improve re-germination and regeneration of sown species. During the two to six years lifespan of wild flower strips, there is essentially a succession of plants from annuals (local weeds together with sown (Agrosternrna githago, Centaurea cyanus, Papaver rhoeas) to biannuals (Cichoriurn intybus, Daucus carota, Echiurn vulgare, Verbascurn denslflorurn) and finally to local grass species together with sown perennial wildflowers (Centaurea jacea, Hypericum perforaturn, Leucanthernurn vulgare, Origanurn vulgare). ECA wild flower strips have been shown to be specific habitats for carabid beetles. In an arable case-study region, about 33,000 beetles belonging to 96 species were trapped (funnel pitfall traps). There were significant differences in species diversity as well as in abundance between the samples trapped in ECA wild flower strips and in arable crops (winter wheat). Wild flower strips are more diverse habitats than adjacent arable crops (plant species and structure of vegetation). This is reflected in the distribution of the carabid species according to habitat and micro-climatic preferences (Figure 2). There are more species and more carabid beetles with specific habitat requirements (xero-thermophilous) in ECA wild flower strips than in the adjacent crop fields.

6 Mostly meso-hygrophylous species more frequent in wheat only in floral fallows only 26 I J \yi g:; rero-thermophylous more frequent in floral fallows / 34 Figure 2: Distribution of carabid beetles in eleven wild flower strips and neighbouring winter wheat fields according to habitat requirements. Source: [l Landscape context It is often difficult to attribute biodiversity indicator values to individual types of biotopes because most species, especially in the agricultural landscape, require not only a single type but a mosaic of biotopes to move and to complete their life-cycles. This can be illustrated by results of butterfly observations. In one of the three case-study areas, 892 butterflies belonging to 17 species have been observed. A model developed with the help of canonical correspondence analysis for butterflies showed that species assemblages are significantly sensitive to landscape features (Figure 3). The surrounding habitat type of the observation site has a major influence. Plant species richness at the site is not sufficient to explain the difference in the species assemblages. On the one hand, butterfly assemblages are influenced by the habitat type (type of ECA). On the other hand, ECAs in the surrounding landscape have a significant influence on butterfly assemblages observed on a given site, which is a result of the extensification rate at the landscape level. In conclusion, there are indications that the introduction of ECA into the agricultural landscape has positive effects on the biodiversity indicators which are examined and - as a consequence - positive effects on agro-biodiversity as a whole can be expected. More data gathering over a longer time span is necessary to confirm or disprove this conclusion.

7 - Habitat Plant species richness Landscape Land cover classes: - forest - ecological compensatory area 4.1% 5.5% Butterfly assemblage Figure 3: Synthetic model of causal relations between environmental variables and butterfly assemblages, based on partial canonical correspondence analysis. Both habitat and landscape descriptors explain a significant part of the variance (p=0.05, Monte Carlo procedure). The arrows are proportional to the percentage of the explained variance. Source: [l 61 4 Monetary valuation of agro-biodiversity in Switzerland Agri-environmental programmes are funded with public money. In the EU in the 1990s about 4 % of the guarantee spending of the common agricultural policy was spent in programmes relating to directive [17]. The question therefore arises of the value of environmental goods and services: is there sufficient value for money and is the public spending justified? The monetary valuation of environmental goods is a controversial issue (e.g. [18]). Often contingent valuation methods are applied to capture the public good aspects of biodiversity although problems related to the construction of the hypothetical market exist [19]. Because in Switzerland the system of political decisions strongly relies on regular ballots, votes in favour of a policy can be interpreted as "political willingness-to-pay" for that policy [4, 201. The problem of constructing a hypothetical market can thus be avoided [21]. During the decade from the mid- 1980s onwards, there has been a number of votes on agricultural policy and of related parliamentary debates and decisions. In this process the country's agricultural policy was re-framed and public spending was re-oriented: - from 1950s to 1980s agricultural policy relied on market and price guarantees, restricting regulations mainly concerned the abiotic environment; : the public rejected a law to support domestic sugar production, for the first time the market support policy was seriously called into question (see e.g. [22]), public awareness on detrimental effects of intensive farming on the environment (namely on biodiversity) and on the amount of public spending for the agricultural sector increased; : a constitutional article that was to become the basis of new agricultural laws and ordinances was rejected against a large majority in parliament and a majority of the political parties because it did not contain a binding paragraph

8 on minimum ecological management preconditions for direct income payments to farmers, nor did it mention a reduction of market support; : a revised constitutional article, which tied direct income payments to basic ecological management requirements found a large (78 %) majority in the. popular referendum; : based on this constitutional article a revised agricultural law was enacted. Public surveys support the view that the budgetary expenditures for agri-environmental measures, including those in favour of biodiversity, are well founded in public preferences. Individual tax payments appear to be within the range of individuals' maximum willingness to pay for the public environmental goods provided by domestic agriculture. Based on this assumption, estimations of the monetary benefits of agri-environmental support can be derived from public expenditures (agricultural budget items). Domestic agriculture as a whole, including all aspects, from food supply security to landscape-aesthetic, cultural, social, and ethic values can be interpreted to produce annual benefits of about CHF 4700 per hectare UAA corresponding with a mean individual willingness to pay of CHF 1000 per capita of the population. The benefits of having a relatively environmentally sound type of agriculture contributes about one third or about CHF 1400 per hectare and CHF 300 per capita to this annual value. Incentives paid for ECA aim specifically at an increase of agro-biodiversity. From national budgets the annual benefits of species diversity can be inferred as about CHF 115 per hectare of the total UAA and year [4]. Payments to farmers for these landscape elements may, if expressed per hectare, be interpreted as their marginal value (Table 2). This approximation is only possible for ECA (Table 1) for which farmers receive additional financial incentives. Table 2: Cost-sharing payments for ECA as incentives to enhance biodiversity. Per capita values are an approximation of the individuals' tax payments for these cost-sharing programme. Source: [4] (modified). Payment class Payments CHF paid per CHF paid per capita (mio. CHF) hectare (a) (b) ECA meadows Hedges and rustic groves Traditional orchard trees per tree 5.05 Wild flower strips Total (a) Payments depending on elevation zone (b) Based on population of 7.1 mio. 5 Conclusions and outlook The Swiss agri-environmental programme, namely the introduction of ECA throughout the agricultural land, can be regarded as a real-world landscape resto-

9 ration experiment. In contrast to some other agri-environmental programmes in Europe which are limited to specific areas (e.g. Environmental Sensitive Areas in the UK), it addresses intensively as well as less intensively managed regions. In the mountain zone, where intensive agricultural management is hampered by unfavourable natural conditions, there is the highest acceptance and the highest share of ECA of the UAA. There, the scheme can be expected contribute to the stabilisation of agricultural management, to the conservation namely of grassland biodiversity and to the prevention of land abandonment. In the lowlands (Swiss Plateau), on the other hand, agriculture has been continuously intensified since the 1950s. There the ECA scheme is supposed to stop the loss of plant and animal species and to stabilise ago-biodiversity. The present agricultural policy has been sanctioned by the public in several referenda. However, the effectivity of the agri-environmental programme and the efficiency of the public money spent for individual measures will be questioned in the future and the new agricultural policy will be challenged as the former was. The environmental goals of the programme are ambitious (no further extinction~ but stabilisation and spreading of endangered species). First positive and encouraging effects are observed but only time will show if goals can be reached. Restoring agro-biodiversity is a long-term undertaking. The restoration process will require significantly more time than the deterioration did. The Swiss agri-environmental scheme is continuously modified. A quality bonus system for ECA which fulfil certain ecological criteria will be implemented in 2001 in order to increase the incentives for farmers to "produce biodiversity". There is a trend towards a regionalisation of the agri-environmental programme. The bonus system, for example, will be put into practice by regional authorities or organisations. It will strengthen the many regional programmes which exist already today and which provide additional financial incentives for particular, locally relevant features and elements of the agricultural landscape. References Cammarata, A. et al. Agriculture and Environment. Bruxelles, CAP Working Notes, Buller, H. Regulation 2078: patterns of implementation. Agri-environmental policy in the European Union, eds. H. Buller, G.A. Wilson & A. Ho11. Ashgate Publishing: Hampshire and Vermont, pp Forni, D., Gujer, H.U., Nyffenegger, L., Vogel, S. & Gantner, U. Evaluation der Okornassnahmen und Tierhaltungsprogramme. Agrarforschung 6, pp ,1999. Giinter, M., Schlapfer, F., Walter, T., & Herzog, F. Direct payments for biodiversity provided by Swiss farmers: An economic interpretation of direct democratic decision., OECD ENVIEPOCIGEEIIBI0(2001)9: Paris, SAEFL & FOA Swiss agriculture on its way to sustainability. Swiss Agency for the Environment, Forests and LandscapeISwiss Federal Office of Agriculture: Bern, 2000.

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