Today habitat loss and degradation is the number one cause of species extinction and loss of biodiversity across the planet. In particular, habitat fragmentation – the separation of habitat landscapes into isolated sections due to natural or human causes – has dramatically impacted the composition of environments and species survival rates. Despite this, a UW study has recently shown that habitat and species recovery is possible through the process of connecting habitat fragments.
After two decades of research, Ellen Damschen, a professor of biology at UW-Madison, has shown with her research project that small modifications to connect habitats leads to species growth, ecosystem recovery, and slowed extinction rates.
Damschen’s research began in 1999 at the U.S. Department of Savannah River Site in South Carolina. There, with permission from the U.S. Forest Service, Damschen and her team of researchers clear-cut 40 patches of savanna on the 170,000 acre site. These isolated patches varied in shape – squares, rectangles, and plus signs – but contained the same area. Following the creation of fragmented lands, narrow corridors were used to connect the patches together. Researchers proceeded to monitor and occasionally manage the land with controlled fires to simulate natural stressors and occurrences.
Over the next two decades of the study, 24 new species of plants appeared on the land after the connection of fragments, which demonstrated a 14% increase in species diversity. Plants that had never surfaced on the land began to grow from both dormant seeds in the soil and outside natural sources. When it came to population size of new species, Damschen’s team discovered that species abundance increased 5% each year without ever stagnating. Additionally, the number of disappearing species annually was 2% less compared to the rate in unconnected fragments. By creating the habitat corridors to connect small fragmented areas, increased species abundance and diversity were supported.
This study could help restore habitats and lands across the country, especially when it comes to Wisconsin’s prairies and savannas. Conservation biologist and statewide habitat management specialist for the Wisconsin Department of Natural Resources, Matt Zine estimates that only 1% of Wisconsin’s savanna and prairie lands are unbroken.
He says, “There used to be a lot of it, and now there’s not much.” The majority of lands remain isolated in small plots separated by surrounding farms, cities, and industrial infrastructure, preventing ecosystem productivity and the maintenance of species diversity and abundance.
In regards to the study, Damschen asserts, “There’s not really a ‘lose’ in connecting habitat. Even at these small scales it appears to have a positive benefit.” In the long run, the simple action of connecting habitats will yield greater species diversity and abundance, enrich ecosystems, and benefit the well-being of this planet and its inhabitants.