Suchergebnisse

To determine the resilience of complex social-ecological systems (SESs) it is necessary to have a thorough understanding of the system behavior under changing political, economic, and environmental conditions (i.e., external system stressors). Such behavior can be predicted if one knows the stable and unstable equilibrium states in a system and how these equilibria react to changes in the system stressors. The state of the system rapidly or gradually changes either toward (i.e., stable equilibrium) or away from (i.e., unstable equilibrium) an equilibrium. However, the equilibrium states in a SES are often unknown and difficult to identify in real systems. In contrast, agent-based SES models can potentially be used to determine equilibria states, but are rarely used for this purpose. We developed a generic approach to identify stable and unstable equilibria states with agent-based SES models. We used an agent-based SES model to simulate land-use change in an alpine mountain region in the Canton of Valais, Switzerland. By iteratively running this model for different input settings, we were able to identify equilibria in intensive and extensive agriculture. We also assessed the sensitivity of these equilibria to changes in external system stressors. With support-vector machine classifications, we created bifurcation diagrams in which the stable and unstable equilibria as a function of the values of a system stressor were depicted. The external stressors had a strong influence on the equilibrium states. We also found that a minimum amount of direct payments was necessary for agricultural extensification to take place. Our approach does not only provide valuable insights into the resilience of our case-study region to changing conditions, but can also be applied to other (agent-based) SES models to present important model results in a condensed and understandable format. ; ISSN:1708-3087

This study presents an analysis of 82 accounts of travel in the United Provinces, written by French travellers who made their journeys between 1748 and 1795. In this period Italy, Britain but also Holland were very popular with French people travelling abroad. The Republic still served as a refuge for those threatened by absolute government or harassed by the judiciary. Moreover Dutch universities and well-established trading firms continued to attract French students and apprentices. In the second half of the eighteenth century increasing number of tourists set out on the journey to Holland, keen to visit a country reputed to be very special. Lovers of fine arts were curious to see the paintings of Flemish and Dutch masters, who were then becoming fashionable. Those interested in politics and infused with the spirit of the Enlightenment could have additional profit from the journey by seeing for themselves one of the few surviving republics of Europe. Zie: Summary

Context
Wild rabbits are considered a key species in the coastal dunes of the Netherlands, but populations have collapsed as a result of viral diseases.

Aim
We studied to what extent population collapse led to local extinction and whether recolonisation of empty patches in the dunes happened.

Methods
We investigated occupancy dynamics using data of 245 transects where rabbits were surveyed in 1984–2009. Dynamic site-occupancy models were used to analyse the data. These models adjust for imperfect detection to avoid bias in occupancy-trend estimation.

Key results
The decline of the rabbit population has resulted in many local extinctions, especially in woodland and in the northern part of the coastal dunes. Most transects along grassland and mixed vegetation have recently been reoccupied. The recovery of woodland occupancy is slow, probably not because of limited dispersal capacity of rabbits, but because the quality of woodland habitats is poor. Detection probability of rabbits varied considerably over the years and among habitat types, indicating the necessity of taking detection into account. Rabbits were slightly better detected when it was cloudy, windy and rainy and when lunar phase approached new moon.

Conclusion
Extinction and recolonisation of habitat patches varied considerably among habitat types.

Implications
The current slow recolonisation hampers the recovery of rabbit populations in woodland habitats in the Dutch coastal dunes. Furthermore, monitoring rabbit occupancy should take imperfect detection into account to avoid biased results.

Maximizing the area under biodiversity-related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short-distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them.

Maximizing the area under biodiversity‐related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short‐distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them. ; PECBMS is supported financially by the RSPB and the European Commission. TT was supported by Institutional Research Plan (RVO: 68081766), SH and LB were supported by EUBON project (308454; FP7‐ENV‐2012 European Commission) and the TRUSTEE project (RURAGRI ERA‐NET 235175), and AL received financial support from the Academy of Finland (project 275606).

Maximizing the area under biodiversity-related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short-distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them. ; Peer reviewed

ABSTRACT The European Union's Natura 2000 (N2000), is one of the largest international networks of protected areas. One of its aims is to secure the status of a pre-determined set of (targeted) bird and butterfly species. However, also non-target species may benefit from N2000. We evaluated how the terrestrial component of this network relates to the abundance of non-targeted, more common bird and butterfly species using data from long-term volunteer-based monitoring programs in 9,602 sites for birds and 2,001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased with the proportion of N2000 sites in the landscape. The corresponding positive relationship was found for 27 of the 104 butterfly species, although most of these species were generalists. These positive relationships disappeared for most of the species when land-cover covariates were taken into account, hinting that land-cover is a primary factor defining the positive effects of the N2000 network. The increase in abundance with N2000 was correlated with the specialization index for bird species, but not for butterfly species. Although the N2000 network supports higher abundance of a large spectrum of species, the low number of specialist butterfly species showing a positive association stresses the need to implement management plan improving the quality of habitats of N2000 areas potentially harboring openland butterfly specialists. For a better understanding of the processes involved, we advocate for a standardized collection of data on N2000 sites. Article impact statement: Across Europe the abundance of a majority of nontarget birds and a quarter of nontarget butterflies increased with Natura 2000 coverage. This article is protected by copyright. All rights reserved ; Peer reviewed