While we often think of connectivity over large-scale landscapes or seascapes, many species benefit from small-scale conservation actions that directly support individual movement. Several recent studies give examples of how connectivity at a more local level can be achieved, particularly in agricultural and other human-dominated settings.
Bats are common residents of cities, and public green spaces provide large, open areas for them to forage. However, private green spaces are often more common and widely scattered, offering a chance for better connectivity. A recent study in Paris shows that one of the most abundant bats of Northern European urban areas, the common pipistrelle (Pipistrellus pipistrellus), benefits from both private and public gardens. Although private gardens make up only 36% of the total green area of the city, they contribute almost half of bat habitat availability. They also decrease the resistance of the city matrix by over half. Urban conservation planning should include the contribution of private green spaces, even when these spaces are small and fragmented.
Like bats, bees can adapt to human-modified environments. Vineyards are a good example of the crossroad between agriculture and insect conservation, covering over 7 million ha globally and supporting a diverse array of pollinators. New research on cavity-nesting bees in vineyards of central Germany reveals that both species richness and abundance increase in vineyards that are close to semi-natural habitats or woody elements such as hedges and remnant forest patches. This connectivity, which provides access to nesting habitat, is more important than whether a vineyard is organic or conventionally managed. These connected habitats have the potential to benefit not only bees, but other insects and larger organisms such as breeding birds.
Some agriculture can benefit from woody elements that are even smaller, such as a few isolated trees or small woody patches. A new study in the tropical lowlands of Mexico looks at the effect that small, isolated arboreal elements have on birds in highly fragmented agricultural settings. Like previous work on small, isolated patches, connectivity improved when there were isolated trees, living fences, small clumps of trees, and other patches smaller than 1 ha, even for species that are poor dispersers. By specifically managing for the spatial distribution of these arboreal elements, volant species have more opportunities for movement and dispersal within an inhospitable matrix.
Like agriculture, roads can disrupt connectivity at the local scale by acting as barriers to movement. However, they also have the potential to act as corridors, especially for small mammals. A new study in southern Portugal looks at the effect of road verges (also called curb strips, nature strips, or roadside buffers) on wood mice (Apodemus sylvaticus) that live near roads bisecting well-preserved woodlands. Although the presence of a road decreases overall connectivity, verges include most of the important microhabitats for maintaining connectivity. Cutting the vegetation in the verges, or plowing nearby land, decreases their ability to act as corridors. Even in regions that are relatively untouched except by roads, road verges can be beneficial for small mammals if managed minimally and in a staggered pattern.
Resources
Mimet, A., Kerbiriou, C., Simon, L., Julien, J.F. and Raymond, R. 2020. Contribution of private gardens to habitat availability, connectivity and conservation of the common pipistrelle in Paris. Landscape and Urban Planning 193: 103671.
Uzman, D., Reineke, A., Entling, M.H. and Leyer, I. 2020. Habitat area and connectivity support cavity-nesting bees in vineyards more than organic management. Biological Conservation 242: 108419.
Cadavid-Florez, L., Laborde, J. and Mclean, D.J. 2020. Isolated trees and small woody patches greatly contribute to connectivity in highly fragmented tropical landscapes. Landscape and Urban Planning 196: 103745.
Galantinho, A., Herrera, J.M., Eufrázio, S., Silva, C., Carvalho, F., Alpizar-Jara, R. and Mira, A. 2020. Road verges provide connectivity for small mammals: A case study with wood mice (Apodemus sylvaticus) in an agro-silvo pastoral system. Journal of Environmental Management 258: 110033.
