Wednesday, May 22, 2013

Cattle help to Eliminate Deforestation

For many years scientists and others alike have come to the conclusion that overgrazing is the main cause of desertification. A biologist, Allan Savory, who recently gave a TED Talk about how to reverse desertification, gave a very compelling yet contradictory speech. He made the bold statement that by putting large cattle herds back on land that has been drying up, it would renew natural soil formation processes and reverse the desertification effect (Savory, 2013). His theology is that naturally thriving ecosystems that were present thousands of years ago used to have large herds of cattle. These cattle herds had populations that were managed by large pack hunters. In defense against predator attacks, the cattle lived and moved in extremely large groups. These densely packed cattle groups had to migrate and move across the land quite frequently because of the massive amounts of manure they would leave on top of their food source. Because of this added nutrients to the ground and the gentle trampling of the hooves, the grass was able to bio decay at a natural rate. This extra litter helped the soil retain more water during the rainy season. Nutrient rich soil is also able to store more carbon from the atmosphere, so it has multiply benefits. To put Savory's techniques to the test, different pieces of land were experimented on by increasing their cattle herds by up to 400%. The cattle were set to mimic nature by doing a planned grazing method that was lead and mapped out by a herd leader or farmer. The idea was to work with nature and change the land cover back to vegetated area at very little cost. In the TED video, Savory was able to show quite a bit of photos displaying his success rates. I admit that after watching the video I was inspired and had a new hope for places suffering from desertification. The methods seemed to be foolproof with little cost and high turnover rates. Nothing to lose there; until the review papers came out.
     James McWilliams wrote a review on Savory's TED talk and displayed some of the caveats of Savory's study in his article. McWilliams mentioned that Savory's study was done between 1969 and 1975 on a 6,200 acre piece of land in the African Country that is now called Zimbabwe. Is this small plot of land supposed to represent the whole world's desertification problems and solutions? The theories Savory discovers in his study seem to be legit in Africa, but do these methods work in the Middle East or in Russia? McWilliams also states that the animals that were being herded in the planned grazing cycle were stressed, fatigued, and had lost so much weight from constant migration that it wasn't even worth it to the land overs to sell the meat from the cattle. Because the cattle weren't getting enough food to sustain their massive movement patterns, the cattle ranchers had to buy expensive food to feed the cows and that made their meat no longer profitable (McWilliams, 2013).

    I agree with Savory's theories and ideas that we need to go back to the basics and do more natural processes to get the land fertile again, but it seems that the cattle are not used to such drastic migration patterns anymore. I think the cattle need to be eased into the migration process, even though the land cover change may be slower. It's not worth it to the farmers if their cattle are fatigued and losing weight. They need their cattle to be health so they can still make a profit on their meat. In a study done by Todd and Huffman, they investigated the difference between heavily grazed and lightly grazed farms and correlated that to the degree of species richness. Surprisingly they found no significant difference between the plant species richness in the heavily grazed plots verses the lightly grazed plots (Todd and Huffman, 1999). This could support my theory that we could use Savory's ideas about bringing back natural grazing patterns but the test areas would be lightly grazed and the cattle would migrate less frequently. Hopefully this would help with the cattles fatigue and stress and help them keep their weight up to a profitable level.

McWilliams, James. "All Sizzle and No Steak." Slate. (2013): n. page. Web. 21 May. 2013.
Savory, Allan. How to fight desertification and reverse climate change. 2013. video. TEDWeb. 20 May 2013.

Todd, S, Hoffman, M. 1999. “A fence-line contrast reveals effects of heavy grazing on plant diversity and community composition in Namaqualand, South Africa.” Plant Ecology. 142: 169-178.

1 comment:

  1. 7 days at the same spot doesn't sound very stressing to me when the common practise is to heard the cattle long distances on daily basis (the imported cattle spieces cant take that walk and they have also much more flesh on their bones and that is exacly the reason they are replacing the originals unfortunately they can bare the conditions). What is the right number of cattle is a nother issue.