Farming and the Fate of Wild Nature

Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
Science (Impact Factor: 33.61). 02/2005; 307(5709):550-5. DOI: 10.1126/science.1106049
Source: PubMed


World food demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on wild species and habitats. We show that farming is already the greatest extinction threat to birds (the best known taxon), and its adverse impacts look set to increase, especially in developing countries. Two competing solutions have been proposed: wildlife-friendly farming (which boosts densities of wild populations on farmland but may decrease agricultural yields) and land sparing (which minimizes demand for farmland by increasing yield). We present a model that identifies how to resolve the trade-off between these approaches. This shows that the best type of farming for species persistence depends on the demand for agricultural products and on how the population densities of different species on farmland change with agricultural yield. Empirical data on such density-yield functions are sparse, but evidence from a range of taxa in developing countries suggests that high-yield farming may allow more species to persist.

Download full-text


Available from: Jorn P W Scharlemann
  • Source
    • "As land must be used to provide food for earth's continuously growing population, the success of biodiversity conservation is tightly linked to our ability to integrate conservation efforts into human-driven landscapes (Fahrig et al., 2011).Two main strategies known as land sparing and land sharing have been proposed to protect biodiversity (Phalan et al., 2011). Land sparing refers to the practice of intensifying agriculture on productive soils to gain areas for efficient species conservation in other places, whereas land sharing aims at integrating conservation and crop production on the same site (also described as wildlife-friendly farming;Green et al., 2005). Up to now, neither of these strategies seems appropriate to achieve all conservation goals and for all land-use systems (Grau et al., 2013). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability to accommodate crop production for an ever-growing human population and achieve conservation of rapidly declining biodiversity remains a challenging task worldwide. In agroecosystems, weed diversity and biomass are frequently assumed to be negatively related to crop yield and biomass. However, positive effects of weed species (pollinator and parasitoid attraction) and different resource acquisition strategies may reduce the competitive character of weeds—a potential that can be exploited within land-sharing approaches (i.e., biodiversity conservation and agriculture on the same site). This study aimed at analyzing the relationships of weed diversity and biomass to crop yield and biomass in coconut and banana fields within an irrigation farming scheme established in former Caatinga seasonal dry forest ecosystems around the Itaparica Reservoir, Pernambuco, Brazil. Within each of 21 selected crop fields, we collected weed diversity and biomass data in the fields’ center and edge along with general information on crop yield and the use of fertilizers and other agrochemical inputs. We found no evidence for a negative relationship of crop yield or biomass and weed diversity. On the contrary, crop yield and weed alpha diversity were significantly positively correlated (Shannon and Simpson indices, evenness). In contrast, weed biomass showed a significant negative correlation to crop yield. The use of organic fertilizer had a significant positive effect on crop yield, whereas no impact of herbicides or insecticides was detected. In addition, the field edge provided habitat for more weed species than the field center. Overall, our data show that in perennial tropical crop fields high yield is not opposed to high weed diversity. Moreover, the data suggest that organic farming in the area will likely not lead to yield losses. Nevertheless, the related weed assemblages inhabited only a few typical species of the native dry forest vegetation which makes their contribution to biodiversity conservation at the landscape scale debatable.
    Full-text · Article · Mar 2016 · Agriculture Ecosystems & Environment
  • Source
    • "Biodiversity conservation is increasingly recognized as a crucial task for sustaining several ecosystem services that improve human wellbeing (Cardinale et al., 2012). Agriculture is among the main causes of biodiversity loss worldwide (Frishkoff et al., 2014; Karp et al., 2012; Pignatti, 1982) and there is increasing awareness that future biodiversity conservation will largely depend on the capability of cultivated areas to provide suitable habitats for species and communities of conservation concern (Baudron and Giller, 2014; Green et al., 2005; Phalan et al., 2011; Wright et al., 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasing development of vineyards in Mediterranean areas worldwide is considered a major driver of conversion of several habitats of conservation concern, including calcareous dry grasslands that are targeted for biodiversity conservation by the European Union, according to Natura 2000 policies. Here, we aim at evaluating the potential of extensive vineyards located in contrasting landscapes (semi-natural vs crop-dominated) for providing suitable habitat conditions to plant species associated with dry grasslands. This study was carried out in one of the economically most important winemaking districts of Italy, characterized by a hilly landscape with steep slope vineyards. We compared plant communities of vineyards in contrasting landscapes with those of the remnants of dry grasslands. Our study demonstrates that landscape composition strongly affects local plant communities in vineyards, with a positive effect of semi-natural habitats bordering the cultivated areas. Our findings thus supply an additional tool for improving the effectiveness of viticultural landscapes for nature conservation. In particular, our results indicate that vineyards on steep slopes could provide moderate chance for the conservation of plant specialists inhabiting calcareous dry grasslands, depending on the landscape composition: vineyards embedded in semi-natural landscapes have more potential for conservation than those in crop-dominated landscapes. Our study also indicates that conservation efforts should aim at (a) decreasing the current management intensity that likely hampers the beneficial effects of semi-natural habitats in the surrounding landscape on local plant assemblages, and (b) strictly conserving the remnants of dry grasslands that are irreplaceable refugia for habitat specialists and species of conservation concern.
    Full-text · Article · Mar 2016 · Science of The Total Environment
  • Source
    • "Two divergent strategies to optimize commodity production and biodiversity conservation in the face of land scarcity have emerged: the land sparing and land sharing strategies (Fischer et al., 2014). With land sparing, agricultural areas are managed intensively, creating the maximum agricultural yield from a minimal area, so that other areas can be " spared for nature " (Green et al., 2005). Land sharing, however, encourages biodiversity within each farm (Fischer et al., 2008), whether by including areas that are structurally similar to native vegetation or having high levels of heterogeneity within the farmed area or along the margins. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Ecosystem services, such as pest control and pollination, are critical benefits of biodiversity important for agricultural production. Predators, including insectivorous birds and ants, can provide important biological controls in agroecosystems, boosting crop yield and offsetting the need for expensive inputs such as pesticides. Local habitat and landscape characteristics can affect the delivery of ecosystem services, thereby influencing optimal land allocation for crop production and biodiversity. In order to better understand the relationship between ecosystem services and the surrounding habitat, we conducted a sentinel pest experiment to investigate predation levels in response to a novel pest on coffee farms in central Kenya. The frequency of predation decreased significantly with increasing distance from adjacent forest fragments and was correlated with bird species richness. Predation was also significantly higher on shade compared to sun coffee farms. We conclude that a land sharing approach, via both the integration of shade trees and the conservation of small forest fragments within or adjacent to a farm, can support increased levels of pest control services provided by birds and ants in Kenyan coffee farms.
    Full-text · Article · Feb 2016 · Biological Conservation
Show more