Tailoring restoration interventions to the grassland‐savanna‐forest complex in central Brazil

Abstract

Defining the reference system for restoration projects in regions characterized by complex vegetation mosaics is challenging. Here we use the Cerrado region of Brazil as an example of the importance of clearly defining multiple natural and anthropogenically altered states in grassland‐savanna‐forest mosaics. We define three main, natural vegetation types–grassland, savanna, and scleromorphic (cerradão) forest–to (1) distinguish between original and degraded states and (2) set appropriate targets for and guide restoration. We contend that the differences in Cerrado vegetation composition originally were driven by soil conditions and secondarily by fire frequency and precipitation patterns that differ from the core to the edge of the Cerrado region. Grasslands are found on the shallowest, least fertile soils and/or in waterlogged soils; scleromorphic forests are generally located on deeper, more fertile soils; and savannas occupy an intermediate position. In recent decades, this biophysical template has been overlain by a range of human land‐use intensities that strongly affect resilience, resulting in alternative anthropogenic states. For example, areas that were originally scleromorphic forest are likely to regenerate naturally following low‐ or medium‐intensity land use due to extensive resprouting of woody plants, whereas grassland restoration requires reintroduction of grass and forb species that do not tolerate soil disturbance and exotic grass competition. Planting trees into historic grasslands results in inappropriate restoration targets and often restoration failure. Correctly identifying original vegetation types is critical to most effectively allocate scarce restoration funding.

A research agenda for the restoration of tropical and subtropical grasslands and savannas

“…TGB transformed to pastures) or with derived grasslands and savannas (e.g. grasslands derived from the degradation of forests), with subsequent recommendations for restoration directed at tree planting (Silveira et al 2020; Schmidt et al 2019a; Fig. 2).…”

Myth‐busting tropical grassy biome restoration

“…Managing the intensity of grazing, fire, or a combination of both should be incorporated in the maintenance and restoration of TGB. Without fire or sufficient browsing in some areas (Schmidt et al 2019), woody encroachment and a biome shift from open to forested vegetation can lead to biodiversity losses, especially for endemic species (Abreu et al 2017; Stevens et al 2017).…”

Mapping native and non-native vegetation in the Brazilian Cerrado using freely available satellite products

“…As a result of land-use changes, areas targeted for restoration have often undergone significant changes in soil structure and nutrient composition 48 , 49 . Despite this, neighbouring native vegetation is a good indicator of whether passive or active restoration approaches might be suitable 44 , the type of vegetation to restore a degraded area to 50 , prospective propagule availability 51 and the potential for maximising ecosystem connectivity 52 . Understanding the matrix of vegetation surrounding a potential restoration area might also minimize the risk of restoration failure due to invasion of exotic species (particularly pasture grasses) 53 and improve our ability to evaluate the potential fire risk to newly restored vegetation.…”