Tropical rainforests are considered the climax stage of forest and the richest in biodiversity compared to other biomes. These forests are under the many pressures of degradation such as deforestation, and now conversion for agricultural purposes has been inching through.
A journal published in Nature Communications features how transformation of forests into agroecosystems are currently trending especially in the tropical rainforests (TRFs) of the Southeast Asia. According to the findings of the study lead by Lund University, monoculture plantations especially oil palm and rubber have been invading the forests of Sumatra, depreciating the ecosystems services which should have been made available if the conversions were controlled in the first place.
Using Jambi, Sumatra as the place of study, lead author Yann Clough in collaboration with 40 other researches from New Zealand, Indonesia, Switzerland and Germany conducted a biodiversity and ecosystems function assessment with interviews involving 450 local farmers. The former was used by the team to measure and quantitatively compare the differences between the natural forests, agroforests and areas with only monoculture practices.
According to the group's investigation, the study area has already lost 75% of their unprotected forest cover from 1990-2011. The great decrease was attributed to the unprecedented increase in monoculture plantations wherein during the same span of time, rubber plantations were observed to increase by 30%, oil palm plantations by 150% and fallow lands or brush lands awaiting for plantation spiked at 300%.
Monoculture does not only affect the tropical rainforests in terms of deforestation but also causes more damages to the natural ecosystem than what we think. Clough's group has identified as well that the conversion of a lowland forest into oil palm and rubber monoculture plantation eventually decreases the soil organic carbon (SOC) by 50%, which later causes less soil stability leading to erosion. Impacts of net primary productivity due to low organic input retention is also another strand of problem in line with the loss of SOCs. Furthermore, monoculture plantation leads to lower floral diversity, in terms of genetic and taxonomic, with more variable microclimate and simpler vegetation structure that reduces faunal biodiversity.
Another issue tackled by Clough and his colleague's paper was the conflict on the economic and social side of the monoculture industry. "For the great majority of small farmers, chopping down diverse forests and investing in a single species of tree -- monoculture -- is the simplest and quickest path out of poverty. Productivity increases, the financial risk drops and income rises," Yann Clough stated in an article. Their team has further recommended that halting the monoculture practice should be accompanied by financial support to the small-scale farmers, backed up by a strong political will.
"Since the small farmers earn more with monoculture, sustainability aspects and the effects on nature currently are almost entirely unheeded. Changing the production methods of small farmers requires financial incentives along with political will; otherwise there is a risk that rich and productive agricultural land will have disappeared altogether in 20 years," Clough added.