Researchers from Japan have discovered that the uncontrolled proliferation of Sika deer in southern Kyushu’s beech forests is leading to soil erosion, which in turn is affecting the growth of Japanese beech trees. This highlights how the ecological balance can be disrupted by changes in a single species. The findings were published in the journal Catena.
In nature, various species interact with each other and their environment through food chains and webs. Any disruption in these chains can have significant consequences on the ecosystem.
The excessive population of Sika deer has resulted in the decline of dwarf bamboo, the primary understorey vegetation in the forests of Southern Kyushu. This loss of bamboo due to overgrazing destabilizes the soil, causing erosion and exposing the roots of beech trees. According to Hayato Abe, the lead author of the study from Kyushu University, this erosion impacts the water and nutrient absorption of the trees, affecting their growth and health.
Through ecological surveys and tree ring analysis, researchers observed a decline in beech tree growth since 1997, coinciding with the increase in deer population and the degradation of understorey plants. The study revealed a correlation between exposed tree roots and slower growth rates, as trees with compromised water absorption abilities exhibit reduced growth.
The gradual weakening of beech trees has cascading effects, such as reduced leaf litter on the forest floor, accelerated soil erosion, and increased vulnerability to environmental stressors. The absence of natural predators for Sika deer in the area has exacerbated the overpopulation issue, making conservation efforts challenging.
To address these challenges, a collaborative approach involving scientists, policymakers, and local communities is necessary for effective forest management and conservation.
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Source: Kyushu University ; Image: Shuterstock
The full article is available at: Soil erosion under forest hampers beech growth: Impacts of understory vegetation degradation by Sika deer.
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