农田野花带群落构建及其稳定性特征

为维持农田野花带稳定性和持久性,以充分发挥其生态系统服务功能并扩大其应用范围,对8个不同建植年限(2、4和6年)的农田野花带混播群落的建立过程,包括群落密度、物种多样性指数以及不同寿命的初始植物和侵入植物重要值的变化规律进行了调查和分析。结果表明:1)播种建立的农田野花带群落,存在2次植物消亡,分别是一二年生植物和短命宿根植物的死亡,导致群落的物种多样性和密度下降,并为侵入植物的进入和扩张提供机会;2)群落中一二年生植物、短命宿根植物设计比例低且长寿宿根植物设计比例高时,植物群落消亡程度小,抑制侵入植物能力强;3)侵入植物能减缓群落物种多样性的丧失。因此,农田野花带混播群落在植物选择方面,应将一二年生植物比例控制在25%以内,并使用长寿宿根植物代替一二年生植物和短命宿根植物可增加群落的稳定性;在群落设计方面,将自生植物保留或纳入设计过程,可减缓群落物种多样性的丧失;在群落管理方面,一二年生植物和短命宿根植物消亡时补播,可提高群落抑制侵入杂草的能力。

Establishment and stability of mixed-sown wildflower strip community

In order to maintain the stability and durability of wildflower strip, 8 communities with different ages(2, 4 and 6 years)in community assembly were investigate and analyzed, including density, Simpson diversity index and important value of annuals/biennials, short-live perennials, long-live perennials and invasive plants. The research results are as follows: 1)There are two extinctions in community caused by annuals/biennials and short-live perennials separately, which decrease species diversity and density and provide opportunities to invasion. 2)Lower proportion of annuals/biennials and short-live perennials and higher proportion of long-live perennials within community will reduce extinction and enhance resistance to invasive plants. 3)Invasive plants can remedy loss of species diversity. This study demonstrates that keeping design proportion of annuals/biennials under 25% and substituting annuals/biennials and short-live perennials for long-live perennials can enhance community stability. Engaging spontaneous herbaceous plants into design process can slow down the loss of species diversity. Conducting supplementary sowing when extinctions begin can improve community resistance to invasive weeds.