Effects of Monocropping on Land Cover Transitions in the Wet Evergreen Agro-Ecological Zone of Ghana

Abstract

The wet evergreen forest ecological zone of Ghana is undergoing notable structural changes, although most maps erroneously depict the area to be an intact forest. Several hectares of plantation agriculture such as rubber, oil palm, and cocoa are replacing the natural vegetation and habitats, thereby threatening indigenous biodiversity. This study aimed to assess the effects of tree monocrop proliferation on landscape transitions between 1986 and 2020 in the Wassa East District of Ghana. The ISODATA clustering technique was used to produce land cover category maps from Landsat images of 1986, 2002, and 2020. A post-classification change detection technique resulted in transition matrices which were used for the computation of land cover transition intensities over 34 years. The results showed that the landscape was dominated by forests in 1986. Still, the forest continuously declined by 34% (1% annually) in 2020 while all other land cover types increased in both periods with cocoa covering 23% oil palm covering 14%, and rubber covering 2% of the land area. These conversions in the land area are important, especially since the closed forests usually transition to monocrops through the intermediate process: food crop farming. This information is essential for decision making on land development and biodiversity conservation.

Soil and Phytomicrobiome for Plant Disease Suppression and Management under Climate Change: A Review

“…Intensive continuous monoculture can be a fundamental problem in field farming systems, horticulture, and agroforestry. As the global population increased, farmers tend to replace intercropping and crop rotation with monocultures of high-value cash crops, seeking higher yields, higher profits, and lower management costs [ 64 , 65 ]. However, long-term monocropping has had detrimental effects on soil health and increased plant diseases by disrupting the micro-ecological environment of the soil.…”

A Review on Soil and Phytomicrobiome for Plant Disease Management

“…But because long-term monocropping disturbs the soil's microecological environment, it has a negative impact on soil health and has led to an increase in plant diseases. A legacy of low Soil Organic Carbon (SOC) and nitrogen, as well as a proliferation of saprotrophic and pathogenic microbes, is left behind by the negative plant-soil feedback over time, ultimately resulting in decreased yields and nutrient-poor soils [41][42][43][44] and Pseudolabrys [45]. Intercropping systems also benefit forest ecosystems by creating disease-suppressive soils when trees are planted in multiple species as opposed to monoculture [46,47].…”