Secondary succession of woody plants following sand mining in the Soesdyke-Linden area, Guyana: A Chronosequence study

Sandy soils comprise a large proportion of low productivity areas of Guyana on the Soesdyke-Linden Highway, where there is ecological disturbance and evidence of secondary succession after sand mining activities. This study investigated secondary succession of woody plants on abandoned sand mining locations. Secondary succession was studied inferentially by comparing sites in a homogeneous zone that was abandoned at different times post disturbance due to sand mining. Species diversity and community composition at five (5) sites which included an undisturbed area and areas at 3, 5, 10, and 15 years after the disturbance of sand mining were studied. Fifteen 10m x 10m plots were sampled for woody plants with a DBH of more than 2.5cm, and 1m x 1m sub-plots were randomly selected and sampled for seedlings with a DBH less than 2.5cm. A total of 241 plants were recorded, encompassing 22 species across 16 Families. Tapiria marchandii of the family Anacardiaceae dominated the chronosequences of 5, 10, and 15 years and recorded the highest Importance Value Index (IVI) of 112.88, 154.51, and 215.42, respectively. Dimorphandra conjugata of the family Fabaceae also adapted well to conditions post sand mining in the latter chronosequences of 10 and 15 years with IVIs of 54.17 and 38.83, respectively. The youngest site of three years exhibited the highest species diversity post the disturbance of sand mining; however, the undisturbed site possessed the highest overall species diversity. Species diversity of chronosequences decreased with age as competition for limited resources increased and the dominant species proliferated.