Farming and the fate of wild nature

Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
Science (Impact Factor: 31.48). 02/2005; 307(5709):550-5. DOI: 10.1126/science.1106049
Source: PubMed

ABSTRACT 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.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: African oil palm has the highest productivity amongst cultivated oleaginous crops. Species can constitute a single crop capable to fulfill the growing global demand for vegetable oils, which is estimated to reach 240 million tons by 2050. Two types of vegetable oil are extracted from the palm fruit on commercial scale. The crude palm oil and kernel palm oil have different fatty acid profiles, which increases versatility of the crop in industrial applications. Plantations of the current varieties have economic lifespan around 25–30 years and produce fruits around the year. Thus, predictable annual palm oil supply enables marketing plans and adjustments in line with the economic forecasts. Oil palm cultivation is one of the most profitable land uses in the humid tropics. Oil palm fruits are the richest plant source of pro-vitamin A and vitamin E. Hence, crop both alleviates poverty, and could provide a simple practical solution to eliminate global pro-vitamin A deficiency. Oil palm is a perennial, evergreen tree adapted to cultivation in biodiversity rich equatorial land areas. The growing demand for the palm oil threatens the future of the rain forests and has a large negative impact on biodiversity. Plant science faces three major challenges to make oil palm the key element of building the future sustainable world. The global average yield of 3.5 tons of oil per hectare (t) should be raised to the full yield potential estimated at 11–18t. The tree architecture must be changed to lower labor intensity and improve mechanization of the harvest. Oil composition should be tailored to the evolving needs of the food, oleochemical and fuel industries. The release of the oil palm reference genome sequence in 2013 was the key step toward this goal. The molecular bases of agronomically important traits can be and are beginning to be understood at the single base pair resolution, enabling gene-centered breeding and engineering of this remarkable crop.
    Frontiers in Plant Science 03/2015; 6. DOI:10.3389/fpls.2015.00190 · 3.64 Impact Factor
  • Meredith C Schuman, Silke Allmann, Ian T Baldwin
    [Show abstract] [Hide abstract]
    ABSTRACT: eLife digest Plants are at the base of many food webs. This means that the different traits and characteristics of the plant species in an ecosystem can have a large impact on the animals and other organisms that live there. Individuals within the same plant species often differ in multiple genes. This ‘genetic diversity’ can affect the populations of other organisms in their ecosystem, for example, by altering which species are present, and the number of individuals. However, previous studies that investigated plant genetic diversity in ecosystems used plants that varied in multiple, usually unknown, genetic traits, which made it difficult to identify specific genetic traits in plants that can influence the whole ecosystem. One way that plants affect their ecosystems involves how they defend themselves against the herbivores that try to eat them. For example, plants can use sharp spines or harmful chemicals to deter herbivores, or attract predators that will attack the herbivores. Here, Schuman et al. carried out a 2-year field study using wild tobacco plants that had been genetically altered to employ different defensive strategies. This was achieved by altering the expression of three genes in the plants in specific combinations. Two of the genes, called LOX2 and LOX3, are required to make most of the chemicals that tobacco plants use to defend themselves against herbivores. The third gene, called TPS10, which comes from the crop plant maize, gives plants the ability to release a fragrance that attracts natural predators of their herbivores. Except for these specific alterations, the plants were otherwise genetically identical. These plants were then grown either alone, or in groups of five plants, which reflects the normal size of groups of wild tobacco growing in its natural environment. The groups contained mixtures of plants with different gene alterations. Schuman et al. found that the expression levels of these genes in individual plants could determine how well the whole group fared in several different measures of plant health and defense. For example, plants lacking LOX2 and LOX3 usually appeared to be less healthy and they were less likely to survive long enough to reproduce because they were less able to defend themselves against herbivores. However, if these plants were grown in a group with one plant that expressed TPS10, all of the plants in the group looked healthier and were more likely to survive long enough to reproduce. Many crops are grown in large fields containing individual plants that are largely genetically identical, which makes them more vulnerable to disease. Schuman et al.'s findings suggest that some of the community-level protective effects provided by diversity in wild populations of plants could be introduced into crop fields by altering the expression of a few specific genes in some individuals. DOI:
    eLife Sciences 04/2015; 4. DOI:10.7554/eLife.04490 · 8.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Land sparing and land sharing are contrasting strategies often aimed at improving both agricultural production and biodiversity conservation in multifunctional landscapes. These strategies are embodied in land management policies at local to international scales, commonly in conjunction with other land-use policies. Evaluation of these strategies at a landscape scale, for multiple ecosystem service benefits, and multiple elements of biodiversity has not previously been attempted. We simulated the effects of applying land sharing and land sparing strategies to the agricultural zones designated by four future land-use scenarios (reflecting both current land-use and prospective land-use plans) in the Ex-Mega Rice Project region of Central Kalimantan, Indonesia. We assessed impacts of each strategy on biodiversity , agricultural production, and other ecosystem service benefits at a landscape scale. We examined whether it was possible to achieve predetermined targets that reflect the aspirations and entitlements of diverse stakeholder groups. We found that the prospective land-use plans for the region would deliver considerably more benefit than the current land-use allocations, and while not all targets can be achieved, additional progress could be made with reasonable and realistic levels of land sharing or sparing. We found that species and forest types sensitive to agricultural disturbance could benefit most if land in agricultural zones was spared and prioritised for conservation. Conversely, land sharing strategies favoured the more widespread and common species, particularly if the area of wildlife-friendly agriculture is increased. However, the effectiveness of agricultural-focused land management strategies is inherently limited by the extent of agricultural zones. While agricultural land sparing and sharing strategies can deliver some gains in target achievement for multiple ecosystem services, we find that they have a limited effect over the benefits achieved by implementing better land-use allocation from the outset.
    Biological Conservation 04/2015; 186:276-286. DOI:10.1016/j.biocon.2015.03.004 · 4.04 Impact Factor

Full-text (2 Sources)

Available from
Jun 4, 2014