出版社：Thai Society of Higher Eduction Institutes on Environment
摘要：This study analyzed the vegetation in the three sites covered by Cu-rich rock mine wastes in Mankayan, Benguet, Philippines. Site 1 is a topsoil amended tailings pond, site 2 is an unamended tailings pond with only about 10%-24% vegetation cover, and site 3 is an agricultural land that was inundated in 1986 by mine rock wastes. Soil samples were analyzed for pH; texture; and Cu, organic matter (OM), available phosphorus, and exchangeable potassium contents. Results show that site 2 had mean soil Cu level of 220 mg/kg, site 1 had 100 mg/kg, and site 3 had 174 mg/kg. Site 2 had mean soil pH value of 4. Sites 1 and 3 had 66%-75% vegetation cover and soil pH of 6.5 and 5.65, respectively. This study proposes a hypothesis on ecological succession as follows: Digitaria sanguinalis and Paspalum conjiigatum community constituted the pioneer stage obsewed in site 2. Improvement in soil environment led the pioneers to be replaced by Cynodon dactylon and P. conjugatum community in site 1,followed by C. dactylon, P. conjugatum, and Mimosapudica community in site 3. The increase in soil OM increased the number of species and vegetation cover in the study sites. The soil environments (i.e., texture, OM, high Cu, and low soil pH) of each site determine the plant communities present in each site. Low soil pH increases Cu solubility.
关键词：Copper; Pioneer species; Ecological succession; Rock mine wastes
