- 期刊
- OpenAccess
Comparative Study of Plant Diversity between Betula alnoides Plantations and Adjacent Natural Forests
西南樺人工林與鄰近天然林植物多樣性比較
摘要
西南樺(Betula alnoides)是我國西南地區重要的鄉土闊葉用材樹種。隨著西南樺人工林在當地的快速發展，掌握西南樺人工群落的性質和動態對於西南樺的可持續經營和發展具有重要的意義。為此，我們在中國西南北熱帶地區對不同樹齡(3、5、8和13年)的西南樺人工林與相鄰的森林植被類型(自然更新的西南樺次生林和熱帶山地雨林)的物種組成、豐富度、多樣性和結構進行了比較研究。在每種植被類型中選擇坡向、坡度及坡位相似的林分設置3塊20×20 m的基礎樣地(共21個樣地)。研究結果顯示：(1)8年及13年生西南樺人工林能具有比天然林高的物種多樣性，其林下植物種類能得到較好恢復；(2)西南樺人工林物種組成和豐富度與造林前的植被類型和林地狀況密切相關，並顯示出同源性和相似的演替趨勢；(3)在西南樺人工林中，物種的豐富度隨林齡的增加也顯著上升，而且林下植被的物種組成由陽性先鋒種向耐陰性和陰性物種轉變；(4)西南樺在中國西南熱帶地區可作為一個重要造林樹種。
並列摘要
Betula alnoides is one of the most important native, broadleaf timber species for plantation establishment in southwestern China. With the rapid expansion of plantations in the region, it is essential to understand the characteristics and dynamics of artificial B. alnoides communities for the sustainable development and management of these forests. We compared the species composition, richness, diversity, and structure between B. alnoides plantations of different age classes (3, 5, 8, and 13 yr old) and previous vegetation types (naturally regenerated B. alnoides secondary forest and tropical montane rainforest) in a northern tropical region in southwestern China. We established 3 basic sampling plots in each forest community (21 total plots, 20×20 m each) with a similar slope direction, grade, and position. The following results were attained. 1) The 8- and 13-yr-old B. alnoides plantations had higher species diversity than the native forest, a trait that can facilitate the development of plant species under the plantation canopy. 2) The species composition and richness of the B. alnoides plantations were significantly related to the previous vegetation type and land conditions before planting and showed a homologous and similar successional trend. 3) In B. alnoides plantations, the species richness significantly increased along with an increasing age of the plantation, and the species composition of the understory vegetation changed from pioneer species to shade-tolerant plants and sciophytes. 4) Betula alnoides can be used as an important reforestation tree species in tropical southwestern China.