Fragmented Landscape, Fragmented Knowledge: A Synthesis of Renosterveld Ecology and Conservation

Abstract

SummaryKnowledge of ecological patterns and processes is key to effective conservation of biodiversity hotspots under threat. Renosterveld is one of the most critically endangered habitats in the biologically unique Cape Floristic Region, South Africa. For the first time, we map and synthesize the current state of knowledge on renosterveld ecology and conservation. We investigated 132 studies for the themes, locations and taxa of renosterveld research and the fragmentation, threats, recommendations and barriers to renosterveld conservation. More studies focused on plants than any other taxa (48% of articles) and are conducted mostly in larger, intact renosterveld fragments. The most commonly identified threat to renosterveld was agricultural intensification; conservation recommendations spanned improved farming practices, formal protection and local patch management. Conservation implementation has been piecemeal and has depended largely on the goodwill of landowners, which can be constrained by costs of conservation measures and a lack of suitable restoration means. Citizen science is a promising potential solution to some barriers. Fragmented knowledge in such a transformed and relatively densely populated region highlights the scale of knowledge gaps for other biodiversity hotspots and has implications for ongoing conservation work.

Locating and dating land cover change events in the Renosterveld, a Critically Endangered shrubland ecosystem

“…Land cover change that occurs slowly over decades or longer as a result of long-term degradation through inappropriate fire regimes, overgrazing or invasive alien species is not captured on the time scale studied here. These factors contribute significantly to the long-term decline of Renosterveld (Topp and Loos, 2019). This may account for the discrepancy between the annual rate of Renosterveld loss reported here of 0.18 % per annum and the annual rate reported by Skowno et al (2019) of approximately 1%.…”

Decision-making for nature’s contributions to people in the Cape Floristic Region: the role of values, rules and knowledge

“…More than 70% of natural vegetation in the CFR has been transformed to other land uses, primarily agriculture but also urbanization (Myers et al 2000). Natural renosterveld vegetation has been particularly susceptible to transformation, due to its rich substrate and relatively accessible topography compared to other habitat types of the CFR (Topp and Loos 2019;Rouget et al 2014). This transformation began in colonial times, although much occurred throughout the twentieth century (Newton and Knight 2005), and has led to major biodiversity losses which threaten the provision of NCP.…”

“…Whereas renosterveld formerly covered much of the Swartland, less than 3% natural west-coast renosterveld vegetation now remains, mostly in fragments on steep slopes and hilltops among intensively farmed private land (Moll and Bossi 1984;McDowell and Moll 1992;Newton and Knight 2005;Halpern and Meadows 2013). While agricultural expansion is the major driver of renosterveld loss in the Swartland, other threats include biological invasions and climate change, which can converge with poor land management and further deteriorate renosterveld (Kemper et al 1999;Topp and Loos 2019). Regional scale conservation planning has taken place across the Cape lowlands (von Hase et al 2003) and private easements are used as a conservation mechanism in south-coast renosterveld (Overberg Renosterveld Conservation Trust, www.orct.org), but conservation approaches remain piecemeal (Topp and Loos 2019).…”

“…While agricultural expansion is the major driver of renosterveld loss in the Swartland, other threats include biological invasions and climate change, which can converge with poor land management and further deteriorate renosterveld (Kemper et al 1999;Topp and Loos 2019). Regional scale conservation planning has taken place across the Cape lowlands (von Hase et al 2003) and private easements are used as a conservation mechanism in south-coast renosterveld (Overberg Renosterveld Conservation Trust, www.orct.org), but conservation approaches remain piecemeal (Topp and Loos 2019). Some renosterveld fragments are designated municipal reserves on the outskirts of towns such as Malmesbury and Darling, but the majority are on privately owned land (Von Hase et al 2010).…”

“…The Swartland landscape is therefore rich in contrasts, with remaining fragments of high biodiversity-value renosterveld largely surrounded by intensive, monocultural grain and fruit production. Such contrast creates a complex decision-making context for land-use planning, as biodiversity conservation implementation is often not a priority for farmers and those responsible for agricultural land-use decision-making (Topp and Loos 2019;Winter et al 2007). In terms of values, previous studies have found farmers to perceive renosterveld as largely unprofitable and associate its retention with problem plants and animals, as well as lack of financial reward (McDowell et al 1989;Von Hase et al 2010;Winter et al 2005Winter et al , 2007.…”