Wet Grasslands as a Green Infrastructure for Ecological Sustainability: Wader Conservation in Southern Sweden as a Case Study

Abstract

Abstract:Biosphere Reserves aim at being role models for biodiversity conservation. This study focuses on the unsuccessful conservation of waders (Charadrii) on wet grasslands in the Kristianstad Vattenrike Biosphere Reserve (KVBR) in southern Sweden. Predation on nests and young has been proposed as one reason contributing to the decline of waders. We explored this hypothesis by comparing two landscapes, one with declining (KVBR) and one with stable (Östergötland) wader populations on managed wet grasslands in southern Sweden. Specifically, we tested three predictions linked to predation on wader nests and young, namely that (1) the relative abundance of avian predators and waders; (2) the avian predator abundance; and (3) the predation rate on artificial wader nests, should all be higher in declining versus stable populations. All predictions were clearly supported. Nevertheless, predation may not be the ultimate factor causing wader population declines. We discuss the cumulative effects of landscape change linked to increased food resources for predators, reduced wet grassland patch size and quality. Holistic analyses of multiple wet grassland landscapes as social-ecological systems as case studies, including processes such as predation and other factors affecting waders, is a promising avenue towards collaborative learning for wet grasslands as a functional green infrastructure. However, if governance and management approaches can be improved is questionable without considerable investment in both ecological and social systems.

Defining Benchmarks for Restoration of Green Infrastructure: A Case Study Combining the Historical Range of Variability of Habitat and Species’ Requirements

“…However, similar declines in wader populations have been recorded over the past 150 years throughout southern Sweden [38,39] and Europe [40]. Wader population declines are associated with the intensification of grassland management leading to changes in both the patterns of land covers [40] and ecological processes [5]. The same applies to the Black grouse [41].…”

“…Kristianstad remains one of Sweden's most important conservation areas for several types of grasslands. As a consequence of the degradation and recognition of the importance of the grasslands, several conservation initiatives have been established to try and manage the area sustainably [5] To understand the historic development of semi-natural grasslands as components of green infrastructure in Kristianstad, we analyzed four different sources of data: (1) Official agricultural statistics from 1927,1932,1937,1944,1951,1956,1961,1971, and 1981 about land covers of Sweden summarized by parishes [28]; (2) the reconnaissance map (scale 1:20,000) made 1812-1820 for the Skåne region [29]; (3) the ordnance survey map (scale 1:50,000) made 1926-1934 for the Skåne region [30]; and (4) Swedish Land Survey land cover maps (scale 1:50,000) 2004 (Table 1) [31].…”

“…The degradation of the semi-natural grasslands of Kristianstad is linked to the declines and local extinction of several wader species (e.g., [5]). Unfortunately, data documenting wader population trends do not extend across more than three decades.…”

“…However, evidence indicates that the abundance and breeding success of bird species are dependent on both the patterns within their biophysical land cover patch (e.g., [63]) and the processes within the surrounding landscape's matrix [64]. For example, avian predator abundance and predation rates of ground nesting birds have been shown to affect their composition and abundance [5,65]. The removal of predators [66] and provision of alternative food [67] has been shown to positively affect the reproductive success of ground nesting birds.…”

“…A wide range of studies have indicated that intensified management and use of natural and cultural land covers (e.g., forests, woodlands, and grasslands) has caused reductions in the composition, structure, and function of biodiversity [3][4][5]. Additionally, urbanization and development of transport infrastructure may directly and indirectly affect both land cover patterns and ecological processes [6,7].…”