Plant Traits and Soil Chemical Variables During a Secondary Vegetation Succession in Abandoned Fields on the Loess Plateau
Plant Traits and Soil Chemical Variables During a Secondary Vegetation Succession in Abandoned Fields on the Loess Plateau
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发表时间：
2002-08
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通讯作者：
Wang Guo
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作者：
Wang Guo
研究了黄土高原废弃地3~149a次生演替过程中植物生物学特性、生态策略、物种丰富度以及土壤化学变量的动态变化。结果表明：(1)随着退耕年限的增加，土壤全碳、全氮呈上升趋势，土壤pH、全钾、全钠呈下降趋势。土壤P沿演替序列变化趋势不明显。而表层(0-10 cm)的总CaO含量则呈下降趋势，而两个深层(20-30 cm、40-50 cm)的总CaO含量则随废弃年限的增加而增加。土壤C、N、K、P随深度增加而降低，而Na、CaO和土壤pH随深度增加而增加。(2)物种丰富度在演替序列的中期和土壤化学变量梯度的中间部分均达到峰值。(3)演替前期较理想的优势种是种子库稳定、CR_LIFE策略、S更新策略、在相对贫瘠的土壤上竞争能力较强的一年生植物，而多年生植物具有较强的横向扩展和克隆能力，对养分供应要求较高，具有C_LIFE策略，是演替后期的优势种。多年生生活史、C_、CR_、SC_、SR_、S和R_LIFE策略、W_、S_、BS_VBS_和V_更新策略等植物性状在其他物种中表现得尤为突出。(4)C_、SC_LIFE策略、克隆能力、多年生生活史、侧向扩展能力、V_和VBS_更新策略、种子动物传播方式、秋季开花时间、豆类和坚果的果实类型等性状与土壤全C、N、K含量有不同程度的相关性，而S_、SR_、R_、CR_LIFE策略、一年、二年生活史、非克隆能力、S更新策略、侧向扩展能力差、椭圆果、荚果的果实类型与土壤全Na、CaO、pH的增加有一定关系。结果表明，与黄土高原的大尺度生态气候条件相适应，草原应是黄土高原的主要天然植被。
Species dynamics in terms of both plant biological traits, ecological strategies and species richness as well as soil chemical variables during a secondary succession in abandoned fields on the Loess Plateau along a temporal sere from 3 a to 149 a were studied. The results indicated that (1) Soil total C and N increased while soil pH, total K and Na decreased with years since abandonment. No noticeable trend was found in the case of soil P along the successional sere. On the other hand, total CaO of the surface layer (0-10 cm) decreased, but that of the two deeper layers (20-30 cm, 40-50 cm) increased with years since abandonment. Soil C, N, K and P decreased, while Na, CaO and soil pH increased with increasing soil depth. (2) Species richness peaked at both mid_stage of the successional sere and the intermediate portion of soil chemical variables gradient. (3) An ideal dominant species in the early successional stage were annuals with stable seed pool, CR_life strategy, S_regeneration strategy, and strong competitive ability on relatively poor soil, while perennials capable of intensive lateral spread and colonal ability, requiring high nutrient supply, and having C_life strategy would be the dominant species in the subsequent stages. Plant traits, such as perennial_life history, C_, CR_, SC_, SR_, S_ and R_life strategies, W_, S_, Bs_ VBs_ and V_regeneration strategies, were over_represented throughout the whole sere among the other species. (4) Some traits, such as C_, SC_life strategies, ability of clonality, perennial_life history, well_developed lateral spread ability, V_ and VBs_regeneration strategies, seed animal dispersal mode, flowering time of autumn, fruit types of legumen and nut, were more or less correlated with increased soil total C, N and K, while S_, SR_, R_, CR_life strategies, annual_, biannual_life history, non_clonal ability, S_regeneration strategy, poor lateral spread ability, and fruit types of utricle, capsule were associated with increased soil total Na, CaO and pH. The results suggested that steppes should be the dominant native vegetation coinciding with the large_scaled eco_climatic conditions on the Loess Plateau.