Search

Copyright of Berichte aus dem Julius Kühn-Institut is the property of Julius Kuehn Institut and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Punctoribates is one of few genera in Poronota (Acari: Oribatida) containing species with porose areas and species with saccules, the two types of the octotaxic system. These porose organs are the main difference between two morphologically similar species, P. punctum with porose areas and P. zachvatkini with saccules. As the octotaxic system can vary within species, species separation solely based on this trait might be insufficient. To assess the species status of P. zachvatkini, we investigated additional differences from P. punctum by comparing habitat preferences of the two species regarding nature reserves and agricultural landscapes during a field study in the German Eifel region, and by examining Punctoribates material from four large German natural history museums. We also performed scanning electron microscopy (SEM) and a genetic analysis using the D3 marker of the nuclear 28S rDNA gene. In the field study, P. zachvatkini had higher densities in the nature reserves and P. punctum in the agricultural landscapes. Evaluation of the museum material revealed P. punctum occurred more regularly in disturbed sites such as urban, agricultural and post-mining areas compared to P. zachvatkini. Pairwise distances of the 28S D3 genetic marker as well as an additional base pair in P. zachvatkini further support the separation of the two species, and SEM investigations revealed new details regarding the punctulation of P. zachvatkini. The review of the museum material showed that P. zachvatkini already occurred in Germany in 1967 and has a wider distribution than previously known. [ABSTRACT FROM AUTHOR]

Kettle holes are found in young moraine landscapes and serve as an important habitat for amphibians. The loss of amphibians has been dramatic in recent decades, mainly because of the increase in land use intensity and deterioration of habitats e.g., kettle holes in agricultural landscapes. We monitored amphibian species on three organically managed farms in north-eastern Germany to get an overview of their occurrence and proof of reproduction to develop effective protection strategies. From 2016 to 2020, we investigated 50 kettle holes in cultivated fields. In 2018, we implemented the nature conservation measure 'cutting back dense wooded belts' in six of these kettle holes. Here, we focused on seven species considering four highly endangered species. We found six to seven species in up to 17 kettle holes in the 44 kettle holes without the measure 'cutting back dense wooded belts'. Bombina bombina occurred at the most kettle holes (57%). The number of kettle holes where amphibians reproduced differed strongly. On average, at least one species reproduced at 58% of the kettle holes. Many kettle holes become overgrown with negative effects for amphibians due to the reduction in solar irradiation and higher water consumption. The nature conservation measure increased the number of species on average from two to four and the number of species with reproduction from one to three. It is one of more than 100 measures in the 'Farming for Biodiversity' project that farmers can choose to receive a nature conservation certificate, which can be used for marketing purposes. [ABSTRACT FROM AUTHOR]

Flower plantings can increase the abundance of bees and improve pollination services in the surrounding landscape. However, uncertainty remains as to whether flower plantings play a role in wild bee conservation. The aim of this study has been to examine the contribution of the composition and management of flower plantings to the attraction of bees, particularly of endangered species. In a large-scale monitoring project, wild bee data were collected on 60 flower plantings and 120 semi-natural reference plots in 20 study sites over 2 years. In total, we recorded 60,335 bees belonging to 351 species. In flower plantings, bee species richness and abundance were intricately linked to high plant richness and constant blooming throughout the season. In the first year of this study, a complimentary blooming phenology of annual and perennial plants resulted in a more constant bloom on flower plantings. In the second year, partial mowing of flower plantings mid-season enhanced floral resources during the late season. As a result, bee richness and abundance in flower plantings increased from the first to the second year. Nevertheless, the compositional heterogeneity of bees over all 20 sites in Germany did not increase from the first to the second year. We conclude that diverse and constant blooming throughout the season is the most important factor for promoting bees in flower plantings. To ensure sufficient beta diversity over a large spatial scale, we recommend the adjustment of seed mixtures according to the geographical region. [ABSTRACT FROM AUTHOR]

Biodiversity conservation in agricultural landscapes continues to be a key challenge in the European Union (EU). However, to date the Common Agricultural Policy (CAP), which is central for addressing this issue, has proven ineffective in improving biodiversity outcomes. In contrast to solutions that focus on individual policies or measures, we take a holistic approach to explore changes in the broader governance system for biodiversity conservation. For this purpose, we draw on a set of four theoretical, ideal-typical scenarios which represent alternative governance approaches and used them to stimulate discussion about the acceptability of contrasting governance approaches among a broad range of actors in three case study areas in Germany and Sweden. Our results highlight that acceptability of alternative governance approaches is shaped by a large variety of factors. Additionally, despite differences between the views and interests of different stakeholder groups, our findings show universal support for governance approaches that fundamentally differ from the status quo approaches. Thus, evaluating and addressing acceptability of alternative governance approaches needs to consider the preferences of many different stakeholders and requires a more holistic perspective. We therefore argue that designing a potentially widely acceptable alternative governance solution for biodiversity conservation in agricultural landscapes requires a blend of different governance approaches. We outline principles that can guide the design of such a blended governance approach and discuss key challenges arising from the suggested changes for both practitioners and future research. [ABSTRACT FROM AUTHOR]

Considerable increases of farmland prices have led to discussions as to whether stronger interventions in farmland markets are necessary or not. However, altered or new interventions in farmland markets should be based on previous analyses of factors causing price differences. To give more insight in the German farmland market, a general spatial model of standard farmland values for arable land in the federal state North Rhine-Westphalia is estimated using municipal level cross-section data. Results indicate high competition for arable land. Urban sprawl and livestock production are the main price drivers. In Germany, a set of legal regulations exists that reinforce these price-increasing impacts and, hence, have counterproductive effects on interventions aiming to reduce price increases. Therefore, it should be more effective and efficient to alter existing regulations that reinforce the price-increasing impacts instead of creating new regulations. [ABSTRACT FROM AUTHOR]

Many of the processes behind the decline of farmland birds can be related to modifications in landscape structure (composition and configuration), which can partly be expressed quantitatively with measurable or computable indices, i.e. landscape metrics. This paper aims to identify statistical relationships between the occurrence of birds and the landscape structure. We present a method that combines two comprehensive procedures: the 'landscape-centred approach' and 'guild classification'. Our study is based on more than 20,000 individual bird observations based on a 4-year bird monitoring approach in a typical agricultural area in the north-eastern German lowlands. Five characteristic bird guilds, each with three characteristic species, are defined for the typical habitat types of that area: farmland, grassland, hedgerow, forest and settlement. The suitability of each sample plot for each guild is indicated by the level of persistence (LOP) of occurrence of three respective species. Thus, the sample plots can be classified as 'preferred' or 'less preferred' depending on the lower and upper quartiles of the LOP values. The landscape structure is characterized by 16 different landscape metrics expressing various aspects of landscape composition and configuration. For each guild, the three landscape metrics with the strongest rank correlation with the LOP values and that are not mutually dependent were identified. For four of the bird guilds, the classification success was better than 80%, compared with only 66% for the grassland bird guild. A subset of six landscape metrics proved to be the most meaningful and sufficiently classified the sample areas with respect to bird guild suitability. In addition, derived logistic functions allowed the production of guild-specific habitat suitability maps for the whole landscape. The analytical results show that the proposed approach is appropriate to assess the habitat suitability of agricultural landscapes for characteristic bird guilds. [ABSTRACT FROM AUTHOR]

Scattered trees support high levels of farmland biodiversity and ecosystem services in agricultural landscapes, but they are threatened by agricultural intensification, urbanization, and land abandonment. This study aimed to map and quantify the decline of orchard meadows (scattered fruit trees of high nature conservation value) for a region in Southwestern Germany for the 1968 2009 period and to identify the driving forces of this decline. We derived orchard meadow loss from 1968 and 2009 aerial images and used a boosted regression trees modelling framework to assess the relative importance of 18 environmental, demographic, and socio-economic variables to test five alternative hypothesis explaining orchard meadow loss. We found that orchard meadow loss occurred in flatter areas, in areas where smaller plot sizes and fragmented orchard meadows prevailed, and in areas near settlements and infrastructure. The analysis did not confirm that orchard meadow loss was higher in areas where agricultural intensification was stronger and in areas of lower implementation levels of conservation policies. Our results demonstrated that the influential drivers of orchard meadow loss were those that reduce economic profitability and increase opportunity costs for orchards, providing incentives for converting orchard meadows to other, more profitable land uses. These insights could be taken up by local- and regional-level conservation policies to identify the sites of persistent orchard meadows in agricultural landscapes that would be prioritized in conservation efforts. [ABSTRACT FROM AUTHOR]

In many temperate regions worldwide, a large portion of deciduous forest grows on former agricultural land, while a smaller portion is ‘ancient’ forest on sites with no historical record of agricultural land use. The differences in species diversity between ancient and post-agricultural forests have been well documented. However, in regions where forest fragmentation occurred only a few centuries ago, it remains unclear whether these differences are due to an extinction debt in ancient forests (i.e., a delay in local species extinction), a colonization credit in post-agricultural forests (i.e., species are yet to colonize a patch), or both. Additionally, our knowledge on how soil conditions and landscape configuration interact with species’ traits to determine the colonization credit is limited. Here, we surveyed ancient and post-agricultural forest patches in NE Germany to quantify the magnitude of the colonization credit and identify its determinants. The colonization credit in an average forest patch amounted to 4.7 forest specialist species and ranged up to 9 species in highly isolated patches. In contrast, we found more species than predicted in patches better connected to ancient forests. The colonization credit was not smaller in older patches than it was in younger ones. Species with a low dispersal potential and a low seed output contributed most to the colonization credit. Our study demonstrates that in a landscape where the extinction debt has already been paid and only a small fraction of ancient forest is left, the recovery of forest specialist diversity in post-agricultural forests may take several centuries. [ABSTRACT FROM AUTHOR]

The knowledge about determinants of species survival is fundamental in conservation. Beyond determinants affecting local population survival, metapopulation theory emphasises the importance of processes operating on larger spatial scales (e.g. dispersal). We studied dispersal capacity and requirements for seedling recruitment of the threatened fen grassland species Trollius europaeus in order to assess the species' ability to persist under the current land use conditions in the study region, north-east Germany. We used a seed sowing experiment and simulated endozoochorous and hydrochorous dispersal in a field and a laboratory experiment. Germination success reflected the experimental reduction of vegetation complexity, but the germination and recruitment rate was overall low. Survival was followed 2008-2011 and was best on plots with an intact moss layer. Mollusc exclusion displayed no significant effect. Endozoochorous dispersal is possible, however, in only minor quantities. Hydrochorous dispersal is very limited and negligible for connecting distant patches. We found evidence for microsite limitation, remnant population dynamics and the existence of unoccupied but suitable habitat patches available for colonization in our study region. However, (re-)colonization events are probably very rare due to dispersal limitation stressing the need for artificial seed transfer within the scope of restoration projects. Therefore, large quantities of seed material should be used in combination with mowing and thorough litter removal but leaving the moss layer intact. Management should be continued for longer than just the introduction year. Our study contributes to the understanding of species dynamics in fragmented landscapes. In particular, it contributes to the conservation of T. europaeus as an indicator of species-rich fen meadows in its Central European range. [ABSTRACT FROM AUTHOR]

How is gradual landscape change perceived and dealt with at the community level? Based on a case study approach, this question is investigated with regards to agricultural abandonment and the subsequent expansion of forests in the Black Forest, Germany. In the case presented, local residents' perception of incremental landscape change does not correspond with a survey on biophysical features of landscape change, but rather focuses on visible effects and exhibits considerable time lags. Facing the same problem, local responses to change in two similarly structured and almost adjacent communities contrast strongly in character and outcomes. I conclude that local perceptions of change as well as specific community identities need to be taken into account in landscape management and policy. The promotion of specific examples of well-performing community-based management strategies, preferably by those people directly involved, should be considered as a particularly valuable dissemination tool. [ABSTRACT FROM AUTHOR]

out 30% of the world's soil carbon is stored in peat soils. Peat land's functional principle of carbon storage greatly depends on management strategies. Therefore, agricultural peat land use becomes a focal point of interest in the current debate on climate protection. Agricultural management demands a drawdown of the water-level that causes degradation of the soils, as well as trace-gas emissions which have a negative impact on greenhouse-gas balance. Climate-friendly peat land management strategies, however, demand enhanced groundwater tables and decreased land-use intensity. Against this background, we analyse ways of re-organising agricultural peat land use within a case study located in Germany, where intensive peat land use accounts for 2.3-5.1% of the country's overall greenhouse-gas emission. The study takes place in six regions which represent all possible socio-economic and natural conditions with regard to the range of existing peat land types, range of management and cultivation types, as well as the range of land-use intensity. To analyse potentials and effects of re-organising peat land use, stakeholder workshops and extensive farm surveys were carried out. The results indicate that reservations exist as regards a re-organisation of peat land management. Financial compensation for farmers appears necessary. The results also show that the potential of rearrangement throughout the regions varies significantly, mainly according to the existing level of interconnection and cooperation between local stakeholders, the technical feasibility of restoration and water logging and the level of agricultural profitability of peat land cultivation with regard to income, capital commitment and the share of affected peat land area. [ABSTRACT FROM AUTHOR]

The disappearance of low-intensity types of agricultural land use such as mowing and grazing is a global phenomenon which leads to changes in species composition and interactions in plant communities. In central Germany, formerly species-rich, semi-natural dry grasslands have been converted into species-poor communities dominated by Festuca rupicola or Poa angustifolia. As a consequence, several forbs have become endangered, and biodiversity has decreased. In a 5-year competition experiment (replacement design; pots were placed outdoors at Halle Botanical Garden), we evaluated the performance of plant-plant interactions between the rare forb Campanula glomerata, F. rupicola and P. angustifolia, respectively. The response of C. glomerata to the presence of the two grass species were measured by stem length, number of flowers and above-ground biomass annually harvested. We did not find significant differences in C. glomerata stem lengths between years and treatments, but flower production, which was highest in the first year, strongly decreased in the subsequent years. Moreover, flower production was lower in combination with P. angustifolia than with F. rupicola. Biomass production showed significant differences between years, but not between treatments. The positive and negative interactions between C. glomerata and the two grass species was estimated by calculating Relative Neighbour Effect Index (RNE). In combination with F. rupicola, interactions switched between facilitation and competition from year to year. In the presence of P. angustifolia, competitive effects on C. glomerata were highest in the second year, but declined from year to year. Curiously, there were no significant correlations between positive and negative interactions with climatic conditions (annual temperature, precipitation and relative air humidity). Our results showed that the response of the rare forb C. glomerata varies with neighbour species, and that fecundity is more prominently affected by competition than stem height or biomass. Our data indicate that biomass removal by traditional land use methods would facilitate the restoration of species-rich dry grassland communities. [ABSTRACT FROM AUTHOR]

Abstract: Agri-environmental measures (AEM) are the central area-based measures of the second pillar of the Common European Agricultural Policy. Cost-effectiveness of AEMs has to be improved. In this paper a newly designed AEM called result-oriented incentive is empirically analysed for the first time concerning its impacts on environmental effects and cost. Result-oriented financial incentives are linked directly to the desired environmental objectives and allow farmers to choose the most efficient way of management to reach them on their own. In this paper, we present the results of 90 interviews with farmers who have participated in a result-oriented AEM in Baden-Wuerttemberg (Germany). We investigated potential advantages (flexibility, innovation, higher intrinsic motivation and improved continuous adaptation). In addition, we researched disadvantages (transaction costs involved in control efforts, risk for farmers). Our results show that such kind of AEM has a positive impact on cost-effectiveness. However, the concrete design and the implementation process of these AEMs play a crucial role for their successful application. [Copyright &y& Elsevier]

Abstract: Hedgerows have been proposed as habitat and conservation corridor for forest plant species, but their importance for the survival of these species is still not clear. The objective of our study was to examine the frequency of occurrence of forest species and total forest species richness in different parts of the hedgerows, and to relate these patterns of occurrence to the species’ habitat requirements and life history traits. We surveyed in total 130 forest-hedgerow transects in North-western Germany, including three age classes. About 77% of all forest plant species (including some endangered taxa) occurring in the neighbouring forests were also found in the adjacent hedgerows. In all age classes, there was a negative relationship between distance from the forest-hedgerow ecotone and the number of species. Ancient hedgerows were not significantly more species-rich than more recent ones. Within 100m distance from the forest edge, forest species richness increased with an increasing number of species in the nearby forest and with an increasing cover of the tree canopy as well as a decreasing cover of the shrub layer. Species with high frequency had comparatively high Ellenberg indicator values for light, and were mostly associated with anemochorous and epizoochorous seed dispersal. The frequency of occurrence in hedgerows of species with common attributes was partly in agreement, partly in disagreement with the results obtained in previous studies. We conclude that patterns are difficult to generalize, probably due to a strong regional variation in the pool of forest species and in the specific environments of both forests and hedgerows. [Copyright &y& Elsevier]

We present a landscape model to investigate the ecological consequences and costs of different management regimes in semi-natural grasslands. The model integrates dynamic abiotic conditions, management (i.e. disturbance) regime and response of more than 50 characteristic plant and insect species by modelling the dynamics of relevant niche parameters as predictors for species distribution models. We compare our results for exemplary scenarios differing in spatial and temporal scales and exemplary species belonging to different functional groups through several steps of aggregation. Our analysis aims at the question whether an infrequent massive disturbance by rototilling can serve as a less expensive alternative to annual mowing for preserving the characteristic species composition of open dry grasslands in Southern Germany. Rototilling results in a shifting mosaic determining the habitat quality for plant and animal species that may reduce the survival of local or regional populations. For some meadow species as well as the encroaching shrub species, rototilling has a detrimental effect on regional habitat quality. Other species, e.g. weeds and annual pioneers, strongly benefit or show only negligible reaction. Since this is a multi-objective problem, there is a no magic bullet in selecting an optimum scenario of measures. But by visualising the trade-off between ecological consequences and costs, our model is a valuable tool for conservation managers providing a sound scientific basis for management decisions relying on available ecological knowledge. It is also an interesting example for a model describing complex communities in a relatively simple way, simultaneously considering the main driving factors. [Copyright &y& Elsevier]

1. The expansion of simplified ecosystems such as intensively managed annual crops plays a big part in driving the global biodiversity crisis. Field-scale diversification, for example leaving weeds to grow in crops, is one way in which diversity in agro-ecosystems can be restored. However, little is known about the determinants of the non-crop plant-based insect communities within arable fields at local and larger spatial scales, an essential component in extrapolating plant diversity benefits to higher trophic levels. 2. We investigated how diversification of agro-ecosystems at the field and landscape levels affects the insect community of the creeping thistle Cirsium arvense. Artificial plots of the host-plant were established in three regions of Germany in 48 paired organic (diverse, weeds not controlled with herbicides) and conventional (simplified, very low weed density and species richness) wheat fields across a gradient of landscape heterogeneity, from simple arable-dominated to heterogeneous, diverse landscapes. 3. Leaf-feeding herbivores were monitored directly, while stem-boring herbivores and their parasitoids were quantified by dissecting the stems of the thistles. Land-use types and naturally occurring thistle stands were mapped within a radius of 1 km around each thistle plot. 4. Herbivore species richness was enhanced by both organic farming and landscape heterogeneity but not by higher densities of thistles in the landscape. For most of the species, host-plant plots in organic fields were more likely to be colonized than those in the conventional fields. The enhancement of diversity in organic fields is probably the result of a slightly higher natural cover of the host-plant Cirsium arvense. 5. Synthesis and applications. Both diversification of landscape (fewer arable crops, more perennial habitats) and extensification through organic management are effective measures of enhancing arthropod diversity on weeds. The impact of field-scale agri-environment schemes on biodiversity should be supplemented by including landscape-scale diversification programmes to include a minimum level of perennial habitat cover. Biodiversity benefits of organic agriculture rely for a large part on non-crop plants. Weed populations should be allowed to coexist with the crop to maintain these benefits, which are threatened by more intensive ‘organic’ management, such as heavy mechanical weed control. [ABSTRACT FROM AUTHOR]

Landscape diagnosis provides a bridge between scientific knowledge and socioeconomic issues that is needed to meet the demands of sophisticated landscape planning and management. The diagnostic assessment of landscape functions (capacities, goods and services supported by the landscape) at different spatiotemporal scales is a valuable tool that can solve the transformation problem. A variety of landscape classification systems including biophysical and landscape units can be applied as a spatial reference system. Examples are described from the multitude of approaches to assess landscape functions that can be employed in landscape diagnosis. The theoretical and methodological aspects of the approach are illustrated using examples both from Germany and the Czech Republic. The examples focus on landscape functions such as groundwater recharge, regulation of water balance, and resistance to wind erosion. in addition, the rarity of and threats to landscape types, landscape aesthetic values, and the landscape character and landscape persistence are discussed. [ABSTRACT FROM AUTHOR]

The effect of sharp edges between three different types of land use on the species richness and structure of ant communities was examined in an agricultural landscape within Central Hesse, Germany. Species richness and nest densities of ants at the centres and the edges of meadows, crop fields, and fallow land were recorded by hand sampling during 1997 and 1998. Edges between different land-use types did not increase ant species richness at the landscape scale, nor were they unique habitats for a specialised ant fauna. Nonetheless, most species shared 'ecotonal effects' in the way that their relative abundance either decreased (e.g. Myrmica scabrinodis) or increased (e.g. Lasius niger, Lasius flavus) at the edges, resulting in different community structure between edges and centres of the land-use types. This was influenced by two major factors: (i) the boundary contrast between the neighbouring habitats (i.e. in terms of disturbance caused by agricultural practices), and (ii) the response of different species to changing abiotic conditions. High nest densities of aggressive species with large colonies occurred along edges. We hypothesise that this can significantly reduce edge permeability for surface-dwelling arthropods. [ABSTRACT FROM AUTHOR]

Aldo Leopold's approach to environmental management changed drastically between the early 1920s, when he advocated predator eradication, and 1944, when he drafted "Thinking Like a Mountain."How are we to understand these changes? It is shown that, early in his career, Leopold developed the basic elements of a conservation ethic, borrowing key elements from the Russian organicist P. D. Ouspensky and from A T. Hadley, an American pragmatist who was president of Yale University when Leopold was a student there. Hadley's pragmatism counseled that we act on the wisdom embodied in the intuitive perceptions of our forefathers. While Leopold changed the presentation of his conservation ethic over the years, he never gave up these key ideas, traces of which remain in the final version of "The Land Ethic." The changes in Leopold's management strategies were not due to a change in metaphysical or moral views, but to his evolving experience as a forester and game manager. Leopold learned that "violent' strategies, such as monocultural planting of trees, pervasive agricultural management of fragile ecosystems and, above all, predator eradication, led to unforeseen and unwelcome results. Leopold recognized that we may never have adequate information to manipulate natural systems for maximal human utility without diminishing their vitality. He therefore lost faith in "economic biology" as a guide to environmental management. Leopold's changing views on management resulted from his experience as an environmental manager, not from a conversion from utilitarian anthropocentrism to biocentric nonanthropocentrism. While Leopold was drawn to Ouspensky's organicism, and he hoped Americans would, through a profound change in their perceptions of nature adopt such a view eventually, he believed throughout his career that long-sighted anthropocentrism provides an adequate basis for conservation practices. El enfoque de manejo ambiental de Aldo Leopold cambió drásticamente alrededor del comienzo de los años 20, cuando abogaba por la erradicación de animales depredadores, y en 1944, cuando produjo "Pensando como una montaña". ¿Cómo vamos a entender estos cambios? Es evidente que, temprano en su carrera, Leopold desarrolló los elementos básicos de una ética conservacionista, tomando elementos claves del organicista ruso Ouspensky y de A. T. Hadley, un norteamericano pragmático, quien fue Presidente de la Universidad de Yale cuando Leopold era un estudiante en la misma. El pragmatismo de Hadley sugería que los seres humanos actuamos basados en la sabiduría expresada en las percepciones intuitivas de nuestros antepasados. Aunque Leopold cambió la presentacióon de su ética conservacionista con elpasar de los años, nunca renunció a estas ideas claves, de las cuales aún quedan vestigios en la versión final de "La Etica de la Tierra". Los cambios ocurridos en las estategias de manejo de Leopold no fueron debidos a un cambio de punto de vista metafísico o moral, sino a su experiencia evolutiva como forestal y manejador de fauna Leopold aprendío que las estrategias "violentas", tales como el monocultivo de árboles, el manejo agrícola extenso en ecositemas frágiles y, sobre todo, la erradicación de animates depredadores, conducían a resultados imprevistos e inoportunos. Leopold reconoció que quizás nunca tengamos la información adecuada para manipular los sistemas naturales para la utilidad máxima de los seres humanos sin disminuir su vitalidad. Por consiguiente, perdió la fe en la "biologia económica" como una guía para el manejo ambiental.… [ABSTRACT FROM AUTHOR]

Kettle holes are small water bodies of glacial origin which mostly occur in agricultural landscapes. They provide numerous ecosystem services (ES), but their supply may be negatively affected by agricultural management. We conducted a literature review to identify which ES are supplied by kettle holes and to analyze feedbacks with agricultural management. Taking Germany as a test case, we also analyzed how kettle holes are addressed in policy documents and for which ES they are regulated. This was done to identify the societal value officially associated with kettle holes. The literature review found eight ES attributed to kettle holes, of which hydrological cycle and flood control, chemical condition of freshwaters, nursery populations and habitats and biotic remediation of wastes were addressed most often. In contrast, only the provision of habitat service was addressed in German policy documents related to kettle holes. We identified types of agricultural management that negatively affected the supply of ES by kettle holes, in particular artificial drainage, high levels of pesticide and fertilizer application, and management where tillage and erosion result in elevated sediment inputs. Additionally, climate change may lead to an increased drying up of kettle holes. Based on our finding, we conclude that the intensity of agricultural management around kettle holes threatens the supply of all ES while only the service of providing habitats for biodiversity is addressed in German policy regulations. Further regulation is required to induce agricultural management change towards a conservation of all ES supplied by kettle holes. [ABSTRACT FROM AUTHOR]