|其他摘要||Amomum tsao-ko is a perennial herb of Zingiberaceae, which grows in subtropical area with much of rainy forests, mainly distributing in partial areas of Yunnan, Guangxi, Guizhou Province, and the north of Vietnam, Laos. The species mainly grows in south, southeast and southwest in Yunnan Province. The maximum output of A. tsao-ko is in Jinping County, Honghe Prefecture in Yunnan. However, there was contradiction between developing community economy and decreasing plant diversity and soil fertility in forests because of extensive management of A. tsao-ko plantations.
The presented paper was attempted to discuss the effects of cultivating Amomum tsao-ko on local community economy, plant biodiversity and soil fertility in the forests based on investigated data from Hetou, Wanchang, Dayangtian, Gaojiazhai, Huizhuqing communities. The purpose of study results was to offer theoretical basis for sustainable development of the plantations in A. tsao-ko distribution areas.
1 Effects of Planting A. tsao-ko on Community Economy
A. tsao-ko, an economically important cash crop, was planted in a large-scale area, which is the primary household income with more than 50% of annually family income in the study communities. The results indicated that: (1) The yield of A. tsao-ko plantations in the Nature Reserve (NR) was obviously higher than of which outside the NR; (2) managed level A. tsao-ko plantations was very extensive in most households. Thus, the management technological dissemination was needed in order to increase A. tsao-ko yield in the study area; (3) the conflict between A. tsao-ko plantation development and the NR conservation was evermore existed since most plantations located in the NR, which would impact A. tsao-ko output. Therefore, gradually establishing A. tsao-ko plantation outside of the NR should be the way of thoroughly solving conflict between A. tsao-ko development and NR resource conservation, which also the way of maintaining sustainable livelihood by increasing CC yield; (4) there was no a network between A. tsao-ko cultivation households in most communities, which confined information and technology dissemination between the farmer households.
2 Influence of A. tsao-ko Plantation on Plant Diversity
Through investigating, inventorying and comparing floral species and their number between woodland segments of natural forests and Amomum tsao-ko plantations, it was found that: (1) there were 28, 18, 10 and 12 arbor and shrub species, and 23, 29, 18 and 25 herbaceous species in the natural forest, A. tsao-ko plantations of juvenile, mature and senile phase, respectively; (2) the coverage of overstorey canopy (including arbor and shrub crown) was 32.5~40.0% for different growing phases of A. tsao-ko plantations, which had significant differences with which of the contiguous natural forests (73.3%); (3) with aging of A. tsao-ko plantations, individual number of overstorey was gradually decreased, Alnus nepalensis was as a great shading species kept in the A. tsao-ko plantation; (4) there were almost the same herbaceous species between the plantations of the juvenile phase (13 species) and the mature phase (12 species), the same of between the senile phase (8 species) and the nature forests (9 species). individual number of herbaceous plants was varied from 92 to 480 in different growing phases of A. tsao-ko plantations. The individual in the senile plantation (201 individuals) was similar to which in the natural forests (229 individuals); (5) the Shannon-Wiener index of arbors and shrubs species in the juvenile, mature and senile A. tsao-ko plantations (1.0520, 1.2142 and 0.8775, respectively) was lower than which in the natural forests (2.3610), while there were no significant differences for Simpson index of herbaceous species within the different growing phases of A. tsao-ko plantations and the natural forests.
3 Influence of A. tsao-ko Plantation on Soil Nutrients
Comparing soil nutrient change between different layer for different growing ages of A tsao-ko plantations, of results showed that: (1) there were significant differences for the contents of organic matter, total N, available P and K (P<0.05) between upper (0-20cm) and low (>20cm) soil layers, while there were no significant differences of total P and K, available N between these two soil layers; (2) organic matter, total N, total P and available K dynamically changed with differing in growing phases of A. tsao-ko plantation. Generally, these nutrient content was lower in the plantations of juvenile and mature phases than which of in the senile phase and natural forests; (3) total K and available N were annually enriched in the upper soil layer, and available N was gradually restored in bottom soil layer as well.
In order to maintaining the sustainability and stability of natural forest ecosystem, A. tsao-ko was suggested to be transformed to artificial forests from the natural forests.|