燕山北部板栗林下杂草群落动态及生态位研究

为准确掌握燕山北部板栗园杂草的发生现状及群落组成,分别于2017年、2018年、2020年对燕山北部板栗林下杂草的种类、数量等进行调查,并运用Levins生态位指数和Pianka生态位重叠指数分析板栗林下优势杂草的生态位动态及群落对资源的利用情况和种间竞争情况。结果表明:(1)2017年、2018年、2020年燕山北部板栗林下杂草群落中分别有53种(27科48属)、47种(24科43属)和44种(24科41属)植物。其中优势杂草15种。(2)15种优势杂草中,葎草和灰绿藜占据较宽的生态位,它们对环境资源利用的多样性程度比较高。鸭跖草、艾蒿、狗尾草、茜草、苦荬菜、白屈菜、紫花地丁、灰绿藜、毛地黄和野大豆等物种对资源的利用能力在逐步增强。(3)杂草群落中生态位重叠值＜0.2的优势物种种对数明显减少,优势杂草物种在逐渐增加对周边资源环境充分利用的能力,灰绿藜逐渐取代葎草的优势地位,进而导致种间竞争关系更加复杂,群落向更高级更合理利用环境资源的群落方向演替,逐步形成更加复杂的种群结构。因此,准确掌握板栗园杂草的发生现状、优势种群及群落组成,可为燕山北部板栗林下杂草的针对性防治提供理论依据。

Dynamics and Ecological Niche of Weed Communities Under Chestnut Forest in Northern Yanshan

The species and quantity of undergrowth weeds of chestnut forest in the northern Yanshan Mountains were investigated. Based on the field survey data of 2017, 2018 and 2020, Levins niche index and Pianka niche overlap index were used to analyze the niche dynamics of major undergrowth weeds, resource utilization, and interspecific competition of chestnut forest. The results showed that:(1) There were 53 species (48 genera, 27 families), 47 species (43 genera, 24 families), and 44 species (41 genera, 24 families) in the understory weed community of chestnut in 2017, 2018 and 2020, respectively. Among them, there were 15 species of dominant weeds. (2) Among the 15 dominant weeds, Humulus scandensand Chenopodium glaucumL. occupied a wider ecological niche and had a higher degree of diversity in their use of environmental resources. The niche width of Commelina communis, Artemisia argyi, Setaria viridis, Rubia cordifolia, Ixeris polycephala, Chelidonium majus, Viola philippica, Chenopodium glaucum, Digitalis purpurea and Glycine soja. were increasing, and these species had increased resource availability. (3) In the weed community, the number of major species with niche overlap value less than 0.2 decreased significantly, and the interspecific competition was more complex. The main weed species gradually increased their ability to make full use of the surrounding resources and environment. Accurate knowledge of weed occurrence, dominant population and community composition in Chestnut orchard can provide theoretical basis for targeted weed control in chestnut understory in northern Yanshan.