Super-regional land-use change and effects on the grassland specialist flora

Abstract

Habitat loss through land-use change is the most pressing threat to biodiversity worldwide. European semi-natural grasslands have suffered an ongoing decline since the early twentieth century, but we have limited knowledge of how grassland loss has affected biodiversity across large spatial scales. We quantify land-use change over 50–70 years across a 175,000 km2 super-region in southern Sweden, identifying a widespread loss of open cover and a homogenisation of landscape structure, although these patterns vary considerably depending on the historical composition of the landscape. Analysing species inventories from 46,796 semi-natural grasslands, our results indicate that habitat loss and degradation have resulted in a decline in grassland specialist plant species. Local factors are the best predictors of specialist richness, but the historical landscape predicts present-day richness better than the contemporary landscape. This supports the widespread existence of time-lagged biodiversity responses, indicating that further species losses could occur in the future.

Species characteristics affect local extinctions

“…Habitat loss and destruction represent the leading cause of biodiversity loss (Vitousek et al., ; Wilcove et al., ; Mace et al., ; Newbold et al., ); they contribute to loss of suitable area, fragment the landscape, and degrade habitat quality (Fahrig, ), all of which may affect species survivorship, establishment, and spread (Pimm, ; Tilman et al., ; Thompson et al., ; Leckie et al., ; Baskin and Baskin, ; Bellemare et al., ; Henle et al., ; Honnay et al., ; Halley et al., ; Nualart et al., ; Ceia‐Hasse et al., ). Therefore, similar to studies wherein species experiencing high rates of habitat loss disappeared from New Zealand (Duncan and Young, ), Spain (Aedo et al., ), Switzerland (Lienert et al., ), England (Walker and Preston, ), and European grasslands (Auffret et al., ), the loss of 14% of the county's prairie species is likely due to the disproportionate amount of prairie habitat lost in the 19th and 20th centuries. This loss of natural grasslands and their biodiversity reflects the ongoing conversion of historically prairie‐dominated landscapes across the midwestern United States, and the effects of past and continuing habitat loss and changes in land use will likely cause further contemporary declines of vulnerable species (Watson et al., ; Auffret et al., ).…”

“…Therefore, similar to studies wherein species experiencing high rates of habitat loss disappeared from New Zealand (Duncan and Young, ), Spain (Aedo et al., ), Switzerland (Lienert et al., ), England (Walker and Preston, ), and European grasslands (Auffret et al., ), the loss of 14% of the county's prairie species is likely due to the disproportionate amount of prairie habitat lost in the 19th and 20th centuries. This loss of natural grasslands and their biodiversity reflects the ongoing conversion of historically prairie‐dominated landscapes across the midwestern United States, and the effects of past and continuing habitat loss and changes in land use will likely cause further contemporary declines of vulnerable species (Watson et al., ; Auffret et al., ).…”

“…This decline in habitat specialists could be due to habitat rarity, given that prairie, while once abundant in Kalamazoo County, had a limited range across Michigan (Chapman and Brewer, ). Alternatively, specialist declines could be due to habitat loss: as prairie habitat remnants disappear or are altered by agriculture and invasion, prairie specialists that are unable to disperse to and survive in other habitat types slowly disappear (Diamond, ; Lawton and May, ; Owens and Bennett, ; Purvis et al., ; Kotze and O'Hara, ; Kotiaho et al., ; Auffret et al., ).…”

“…For species that had gone extinct, community association was based on where it was historically reported (McKenna, ). We hypothesize that habitats that have experienced high rates of degradation and loss (e.g., prairies) will experience high rates of species loss (Duncan and Young, ; Lienert et al., ; Walker and Preston, ; Aedo et al., ; Auffret et al., ). Species origin: Classified as native or nonnative in Michigan, determined from the USDA PLANTS Database. We hypothesize that native species are more likely to be lost than nonnative species, as native species are more often lost than nonnative species in several other habitat types (Suding et al., ; Weigmann and Waller, ; Farnsworth and Ogurcak, ) and invasive species may thrive in the face of human disturbance and anthropogenic environmental change (Dukes and Mooney, ). Range edge: Classified as “edge” or “central” species, determined from the USDA PLANTS Database.…”

“…In butterflies, for example, species with narrow niche breadth, restricted resource use, poor dispersal ability, and low reproductive rates are at high risk of extinction (Kotiaho et al., ; Öckinger et al., ), while in mammals, characteristics such as geographic range and life history strategy have been associated with extinction risk (Davidson et al., ). In plants, native species (Suding et al., ; Weigmann and Waller, ; Rogers et al., ), forbs (Leach and Givnish, ; Soons and Heil, ; Smart et al., ; Weigmann and Waller, ), perennials (Grashof‐Bokdam, ; Verheyen et al., ; Suding et al., ), habitat specialists (Rich and Woodruff, ; Fischer and Stöcklin, ; Preston, ; Preston et al., ; Davies et al., ; Kolb and Diekmann, ), and species experiencing high rates of habitat loss (Duncan and Young, ; Lienert et al., ; Aedo et al., ; Auffrett et al., ), among others, experience high rates of local extinction. Identifying traits associated with species that have been lost from a given geographic area or habitat may help elucidate the characteristics that help or harm species in the face of global change and may aid in the development of strategies to manage and conserve species with similar characteristics (Cardillo et al., ; Farnsworth and Ogurcak, ; Razgour et al., ; Romeiras et al., ; Bai et al., ).…”