It’s 600-odd pages, but the Dasgupta Review on The Economics of Biodiversity, out today, may turn out to be worth reading in full, if these results of quick searches are anything to go by:
…widespread use of individual strains could deepen problems caused by the lack of genetic diversity in crops; introducing resistance into a wide variety of cultivars would counter this.
…future crop security in agriculture and industry is reliant on maintaining plant genetic diversity (Jump, Marchant, and Peñuelas, 2009). Another example of keeping our options open is the development of seed banks. Seed banks store the living genetic diversity of plants, in the form of seeds, to enable future use. Various types of seed bank exist, to support different sectors and interventions, e.g. agriculture, forestry, restoration and conservation. They provide a secure and relatively low-cost method of conserving a large amount of genetic material in a relatively small space.
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The Adapting Agriculture to Climate Change Project was a global initiative covering 24 countries that focused on the seeds of wild relatives of 29 of the world’s most important crop species (Castañeda-Álvarez et al. 2016). Participants in this project have conserved 242 taxa of crop wild relatives. These collections will be used to identify traits of value in crop breeding, such as tolerance of heat, drought, salinity and waterlogging, resistance to pests and diseases, resistance to root rot, and yield.
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Sustainable intensification seeks to use contemporary methods to increase crop yields. For example, maintaining soil fertility, improving water use efficiency and reducing chemical inputs can be achieved through zero tillage or intercropping with two or more crops. Other approaches include plant breeding for temperature and pest tolerance, creating bio-controls for crop pests and pathogens, and reducing fossil fuel use in agriculture…
In the meantime, read the hot takes from The Guardian and Kew.
LATER:
The Dasgupta report is a vast compilation but seems to have `feet of clay’ in the context of biological diversity.
On p. 36 it claims that: “…biodiversity plays the same role in natural capital as diversity does in financial portfolios: it reduces variability (uncertainty) in yield.” This is spurious comparison. Financial portfolios are a result of intelligent management: in Nature there is no intelligence whatever in assembling species nor is there any purpose in reducing yield variability. Some of the most productive vegetation is in fact monodominant (Mora forests, mangroves, reed beds all over the place). The Dasgupta report ignores vast areas of global vegetation with an evolutionary history of often tens of millions of years.
There is confusion: one example p. 69 “… diversity enhances ecosystem productivity”, closely followed on p. 70 “…kelp forests are among the most productive ecosystems in the world”. But kelp (Macrocystis pyrifera) is monodominant. It doesn’t need diversity to be the largest of the algae and the fastest growing plant and a huge supplier of ecosystem services.
Page 69 tries to relate functional diversity to ecosystem productivity but cites just five papers, four of which are co-authored by Tilman, with nothing cited from the large corpus of papers challenging Tilman. This is not acceptable.
Page 72 gives praise to another Tilman et al. paper [https://doi.org/10.1038/nature01014], described by Dasgupta as: “… an illuminating study [of] the positive feedback between modern agricultural practices and biodiversity loss leading in turn to weakening the basis of crop production …”. In this paper Tilman et al. claim: “…Recently, an important and costly pathogen of rice was controlled in a large region of China by planting alternating rows of two rice varieties” This refers to the infamous Zhu et al. 2000 paper, now widely discredited, which did not report `alternating rows’ but a 1:6 mixture of traditional susceptible rice planted with a modern hybrid rice bred to be disease resistant variety.
The six hundred and two pages of the report are undermined by a couple of pages where Dasgupta gets the ecology (and Nature) very wrong.