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2003
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Journal of applied ecology, 40.
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Ajouter le résultat dans votre panierHow effective are European agri-environment schemes in conserving and promoting biodiversity ? / David Kleijn in Journal of applied ecology, 40 ([01/01/2003])
Titre : How effective are European agri-environment schemes in conserving and promoting biodiversity ? Type de document : Imprimé Auteurs : David Kleijn ; Willliam J. Sutherland (1956-) Année de publication : 2003 Article en page(s) : 947-969 Langues : Français (fre) Résumé : Increasing concern over the environmental impact of agriculture in Europe has led to the introduction of agri-environment schemes. These schemes compensate farmers financially for any loss of income associated with measures that aim to benefit the environment or biodiversity. There are currently agri-environment schemes in 26 out of 44 European countries. Agri-environment schemes vary markedly between countries even within the European Union. The main objectives include reducing nutrient and pesticide emissions, protecting biodiversity, restoring landscapes and preventing rural depopulation. In virtually all countries the uptake of schemes is highest in areas of extensive agriculture where biodiversity is still relatively high and lowest in intensively farmed areas where biodiversity is low. Approximately $24·3 billion has been spent on agri-environment schemes in the European Union (EU) since 1994, an unknown proportion of it on schemes with biodiversity conservation aims. We carried out a comprehensive search for studies that test the effectiveness of agri-environment schemes in published papers or reports. Only 62 evaluation studies were found originating from just five EU countries and Switzerland (5). Indeed 76% of the studies were from the Netherlands and the United Kingdom, where until In the majority of studies, the research design was inadequate to assess reliably the effectiveness of the schemes. Thirty-one percent did not contain a statistical analysis. Where an experimental approach was used, designs were usually weak and biased towards giving a favourable result. The commonest experimental design (37% of the studies) was a comparison of biodiversity in agri-environment schemes and control areas. However, there is a risk of bias if either farmers or scheme co-ordinators select the sites for agri-environment schemes. In such cases the sites are likely to have a higher biodiversity at the outset compared to the controls. This problem may be addressed by collecting baseline data (34% of studies), comparing trends (32%) or changes (26%) in biodiversity between areas with and without schemes or by pairing scheme and control sites that experience similar environmental conditions (16%). 5. Overall, 54% of the examined species (groups) demonstrated increases and 6% decreases in species richness or abundance compared with controls. Seventeen percent showed increases for some species and decreases for other species, while 23% showed no change at all in response to agri-environment schemes. The response varied between taxa. Of 19 studies examining the response of birds that included a statistical analysis, four showed significant increases in species richness or abundance, two showed decreases and nine showed both increases and decreases. Comparative figures for 20 arthropod studies yielded 11 studies that showed an increase in species richness or abundance, no study showed a decrease and three showed both increases and decreases. Fourteen plant studies yielded six studies that showed increases in species richness or abundance, two showed decreases and no study showed both increases and decreases. Synthesis and applications. The lack of robust evaluation studies does not allow a general judgement of the effectiveness of European agri-environment schemes. We suggest that in the future, ecological evaluations must become an integral part of any scheme, including the collection of baseline data, the random placement of scheme and control sites in areas with similar initial conditions, and sufficient replication. Results of these studies should be collected and disseminated more widely, in order to identify the approaches and prescriptions that best deliver biodiversity enhancement and value for money from community support." Identifiant : DOI : 10.1111/j.1365-2664.2003.00868.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=147261
in Journal of applied ecology > 40 [01/01/2003] . - 947-969Kleijn, David, Sutherland, Willliam J. (1956-) 2003 How effective are European agri-environment schemes in conserving and promoting biodiversity ? Journal of applied ecology, 40: 947-969.Documents numériques
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Titre : Plant traits as predictors of performance in ecological restoration Type de document : Imprimé Auteurs : Richard F. Pywell ; James Bullock ; David Roy ; Liz Warman ; Kevin John Walker ; Peter Rothery Année de publication : 2003 Article en page(s) : 65-77 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Restauration des écosystèmes
[CBNPMP-Thématique] RevégétalisationRésumé : 1 There are few studies of the performance of species in restored vegetation communities. Here we report the results of a meta-analysis of 25 experiments concerned with species-rich grassland restoration on ex-arable land and agriculturally improved grasslands situated at a wide range of locations throughout lowland Britain. Differences in species’ performance were related to 38 physiological and morphological traits. 2 An experiment-adjusted performance index was calculated for each of the 58 species (13 grasses and 45 forbs). The performance index was calculated for the first 4 years after establishment together with a temporal trend. 3 Individual species showed large differences in performance indices. However, grasses consistently out-performed forbs. 4 We examined the linkage between species’ performance and traits according to four non-exclusive hypotheses. The ability to establish and persist in restored vegetation communities requires: (H1) good gap colonization ability; (H2) strong competitive capability; and (H3) ability to undergo vegetative regeneration. (H4) Successful species are generalists associated with fertile habitats. 5 Trait analyses supported all four hypotheses. Within the forbs, good establishment in the first year was linked to traits determining colonization ability: ruderality, percentage germination of seeds and autumn germination. However, traits linked to competitive ability, vegetative growth and seed bank persistence became increasingly important determinants of success with time. Species with generalist habitat requirements, and especially those associated with fertile soils, performed increasingly well with time. This reflects the development of a closed vegetation in which the ability to grow vigorously and out-compete other established plants is important. 6 Stress-tolerators, habitat specialists and species of infertile habitats performed badly. This may reflect high residual fertility in restored grasslands and particular niche requirements of these species. This may be a problem as grassland restoration often targets communities characterized by species with these traits and many are food plants of invertebrates of conservation value. 7 There were few significant correlations between the performance of the grasses and traits reflecting their overall good performance in comparison with the forbs. 8 This study has important implications for practical restoration programmes and policies. Efficiency might be increased by introducing only species with good performance, but this would lead to uniformity among restored grasslands and would diminish the benefits of habitat restoration for national and regional biodiversity. 9 Synthesis and applications. Future work should focus on practical methods to increase the successful establishment of the poor performing but desirable species, by (i) targeting restoration to low fertility soils, (ii) changing the abiotic environment or (iii) the ‘phased introduction’ of species several years after restoration, when both the plant community is more stable and the environmental conditions are more favourable for establishment. Note de contenu :
Identifiant : DOI : 10.1046/j.1365-2664.2003.00762.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148808
in Journal of applied ecology > 40 [01/01/2003] . - 65-77Pywell, Richard F., Bullock, James, Roy, David, Warman, Liz, Walker, Kevin John, Rothery, Peter 2003 Plant traits as predictors of performance in ecological restoration. Journal of applied ecology, 40: 65-77.Documents numériques
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Titre : Microsite availability and establishment of native species on degraded and reclaimed sites Type de document : Numérique Auteurs : Asrun Elmarsdottir ; Ása L. Aradóttir ; M. J. Trlica Année de publication : 2003 Article en page(s) : 815-823 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Restauration des écosystèmes
[CBNPMP-Thématique] RevégétalisationRésumé : 1 Restoration of native plant communities on previously disturbed land requires the identification and modification of environmental factors that impede or restrict ecosystem succession or development. One of the key factors in successful reclamation is to ensure colonization and persistence of native species within an area. Therefore, the identification of microsite types that favour colonization by native species should improve our ability to successfully reclaim degraded areas.
2 The objectives of this study were to (i) identify and describe microsite types that were conducive to the establishment of five native plant species (Euphrasia frigida, Galium normanii, Thymus praecox, Cerastium spp. and Rumex acetosa) on degraded and reclaimed sites in Iceland; and (ii) to determine the effects of reclamation activities that included the application of manure and inorganic fertilizer on the distribution of microsite types and seedling establishment. Reclamation sites of different ages were examined on an eroded area where the target community was a grass or shrub heath.
3 The spatial distribution of plant establishment was not random but varied among microsite types and study sites. More seedlings than expected were found in microsite types characterized by small rocks and biological soil crusts. These may have entrapped seed and provided more soil stability and moisture than other microsite types. The cover of these microsite types varied among the study sites but the pattern of seedling establishment among the five native forbs was similar.
4 Synthesis and applications. Practical reclamation methods are improved by identifying those factors that promote successful seedling establishment by native species. Application of fertilizer without additional seeding proved to be a simple reclamation approach that increased the availability of one favourable microsite type, enhanced the establishment of native species and subsequently allowed vegetation cover to expand. Seed of native plants may be difficult to obtain commercially, but this approach can be used on degraded land where propagules are available but recovery is slowed by soil instability or nutrient limitations.Identifiant : DOI : 10.1046/j.1365-2664.2003.00848.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155891
in Journal of applied ecology > 40 [01/01/2003] . - 815-823Elmarsdottir, Asrun, Aradóttir, Ása L., Trlica, M. J. 2003 Microsite availability and establishment of native species on degraded and reclaimed sites. Journal of applied ecology, 40: 815-823.Documents numériques
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Titre : Restoration in applied ecology : editor's introduction Type de document : Numérique Auteurs : S.J. Ormerod Année de publication : 2003 Article en page(s) : 44-50 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Revégétalisation Résumé : 1 The need to rehabilitate and restore ecological resources degraded by overuse was already established when the Journal of Applied Ecology was launched in 1964. In the intervening 40 years, submissions on restoration have increased and now contribute at least 8–12% of the papers published annually. Examples from subjects such as conservation biology, pollution ecology and ecological modelling show that notions of restoration or recovery are now implicit in the philosophy of applied ecology.
2 The terminology of restoration ecology is increasingly clear, but there is still debate about the definition of restoration end-points. Although restoration constitutes the process of assisting recovery, success ultimately depends on whether populations, communities and ecological functions attain limits typical of un-degraded reference systems. With evidence increasing that the removal of stressors is not always sufficient to guarantee restoration success, the true arbiters will be the organisms and processes at which restoration is aimed. Stringent appraisal on these ecological criteria will be required if restored systems are to conserve biodiversity and deliver ecosystem services to the extent that many restoration ecologists believe is possible.
3 Botanical systems have figured most prominently among the Journal's restoration papers, but there is increasing emphasis on the restoration of individual populations or species, often invertebrates or vertebrates such as birds.
4 Recent contributions on restoration to the Journal of Applied Ecology include projects seeking the ideal technical solutions to specific restoration problems. Other papers are distinguished for their seminal value and often show that intervention is preferable to natural succession in delivering a successful outcome. Examples range from species and ecosystem-level restoration to real evidence that large-scale restoration can be achieved by policy instruments such as agri-environment. Papers published in the Journal also show how restoration can bring ecological value to urban locations, where many people now gain their first-ever wildlife experiences.
5 Synthesis and applications. This special profile of five papers follows these themes in developing the assessment of restoration end-points, in understanding the restoration process, and in identifying factors that promote success or bring failure. Restoration ecology offers yet another example where the application of ecology simultaneously provides academic leadership and solutions to real environmental problems. In an era in which the adverse economic and ecological consequences of environmental degradation are increasingly unacceptable, restoration ecology is emerging as one of the most important disciplines in the whole of environmental science.Identifiant : DOI : 10.1046/j.1365-2664.2003.00799.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155892
in Journal of applied ecology > 40 [01/01/2003] . - 44-50Ormerod, S.J. 2003 Restoration in applied ecology : editor's introduction. Journal of applied ecology, 40: 44-50.Documents numériques
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Titre : Modelling the emergence response of weed seeds to burial depth : interactions with seed density, weight and shape Type de document : Imprimé Auteurs : A.C. Grundy ; Andrew Mead ; S. Burston Année de publication : 2003 Article en page(s) : 757-770 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Banque de semences dans le sol
[CBNPMP-Thématique] Germination
[CBNPMP-Thématique] Longévité des semences
[CBNPMP-Thématique] Restauration des écosystèmesRésumé : 1 Weeds play an important role in arable and horticultural habitats, and models are being developed to improve our understanding of their population dynamics. The position of a weed seed in the soil profile influences the probability of a seed germinating, emerging successfully and its relative time of emergence. Identifying a relationship between the shape or weight of a seed and its ability to emerge from depth may allow the development of generic models. The aim of this study was to quantify seed response to burial depth, to improve the wider application of existing seedling emergence models.
2 A field experiment used weed seeds sown at different depths and densities in a standard substrate. In addition, two laboratory studies used pre-germinated seeds of the same range of species, buried at a range of depths in optimum conditions using the same substrate. These studies explored the effects of seed size, shape and sowing density on seedling emergence and also enabled reserve-dependent pre-emergence mortality to be quantified.
3 The largest and heaviest of the seeds tested overall, Veronica hederifolia, emerged from the greatest depth (8 cm). In contrast, Tripleurospermum inodorum and Veronica arvensis, the two smallest species, showed a sharp decline when burial exceeded 1 cm. However, the link between seed shape or weight and the ability to emerge from depth suggests a complex relationship. Given optimum conditions, some species (Stellaria media and Chenopodium album) have the physical reserves to emerge from a wider range of burial depths than normally observed in the field, suggesting an ability to exploit opportunities when they occur.
4 For some species, emergence was reduced at high seed densities (e.g. Veronica arvensis). These responses may be associated with traits that have evolved to counteract sibling competition.
5 Synthesis and applications. Generic models identifying the maximum depths for seed germination and emergence have a number of practical applications. For example, they can be used to target cultivation to deplete the weed seed bank or to prescribe the optimum depth of mulches to favour certain species. Our model showed that, in general, larger-seeded species emerged from deeper in the soil, but the relationship between seed size and shape and emergence was complex, possibly species specific. Our germination data may also assist our understanding of the relative importance of different causes of seed losses, particularly from different zones of the soil profile, such as the soil surface. Understanding the component processes of seed behaviour and germination is essential to developing sustainable weed management practices in agriculture and horticulture, and the work reported here contributes to a larger programme modelling weed seed bank population dynamics.
Identifiant : DOI : 10.1046/j.1365-2664.2003.00836.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155893
in Journal of applied ecology > 40 [01/01/2003] . - 757-770Grundy, A.C., Mead, Andrew, Burston, S. 2003 Modelling the emergence response of weed seeds to burial depth : interactions with seed density, weight and shape. Journal of applied ecology, 40: 757-770.Documents numériques
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