Shifting baselines in the restoration ecology of Renosterveld

Authors:
Cherie Forbes

Publication Date:
2019

Abstract/Summary:
Ecological baselines are important in informing restoration targets. Baselines can shift, however, depending on the timescale of observation. Using observations from the past few years or decades can give a misleading impression of the historical range of variability, and the extent of recent human transformation. Palaeoecological techniques can track interacting effects of climate change and land-use on vegetation composition and fire regimes over decadal–millennial timescales, thereby informing ecologically possible conservation management options and restoration targets. In the Cape Floristic Region, South Africa, European settlement and subsequent land transformation led to dramatic changes in land-cover. Ninety-six percent of Renosterveld, a highly diverse indigenous shrubland, has been transformed. Thus, appropriate management of remaining fragments is critical to biodiversity conservation. However, we know little of the Renosterveld landscapes before the mid-17th century. This study used fossil pollen, coprophilous fungal spores and charcoal to track vegetation, herbivory and fire at centennial timescales in one of the few remaining Renosterveld fragments. Results showed that the current landscape is atypical compared with the long-term history of the site, with higher abundance of Renosterbos (Elytropappus rhinocerotis), local fires, and herbivory that reflect intensive utilisation beginning in the mid-20th century. To accommodate uncertainties in future environmental change, we recommend an adaptive management approach, which incorporates palaeoecological analyses, burning and grazing experiments, and long-term monitoring. Managing the integrity of Renosterveld at this site according to a pre-colonial baseline requires lower levels of herbivory and fire.

Resource Type:
Audio/Video, SER2019

Pre-approved for CECs under SER's CERP program

Source:
Society for Ecological Restoration