College of Landscape Architecture and Forestry, Qingdao Agricultural University, No. 700 Changcheng Road, Qingdao 266109, P.R. China; Academy of Dongying Efficient Agricultural Technology and Industry on Saline and Alkaline Land in Collaboration with Qingdao Agricultural University, Dongying 257347, China.
Qingdao Key Laboratory of Ecological Protection and Restoration, School of Life Sciences, Shandong University, 72 Binhai Road, Qingdao 266237, China.
Sci Total Environ. 2024 Jun 1;927:172292. doi: 10.1016/j.scitotenv.2024.172292. Epub 2024 Apr 6.
Trace element pollution has emerged as an increasingly severe environmental challenge owing to human activities, particularly in urban ecosystems. In farmlands, invasive species commonly outcompete native species when subjected to trace element treatments, as demonstrated in experiments with individual invader-native pairs. However, it is uncertain if these findings apply to a wider range of species in urban soils with trace elements. Thus, we designed a greenhouse experiment to simulate the current copper and zinc levels in urban soils (102.29 mg kg and 148.32 mg kg, respectively). The experiment involved four pairs of invasive alien species and their natural co-existing native species to investigate the effects of essential trace elements in urban soil on the growth and functional traits of invasive and native species, as well as their interspecific relationship. The results showed that adding trace elements weakened the competitiveness of invasive species. Nonetheless, trace element additions did not change the outcome of competition, consistently favoring invasion successfully. Under trace element addition treatments, invasive species and native species still maintained functional differentiation trend. Furthermore, the crown area, average leaf area and leaf area per plant of invasive species were higher than those of native species by 157 %, 177 % and 178 % under copper treatment, and 194 %, 169 % and 188 % under zinc treatment, respectively. Additionally, interspecific competition enhanced the root growth of invasive species by 21 % with copper treatment and 14 % with zinc treatment. The ability of invasive species to obtain light energy and absorb water and nutrients might be the key to their successful invasion.
微量元素污染是人类活动引起的一个日益严重的环境问题，特别是在城市生态系统中。在农田中，当受到微量元素处理时，入侵物种通常会比本地物种更具竞争力，这在单个入侵物种-本地物种对的实验中得到了证明。然而，目前还不确定这些发现是否适用于城市土壤中含有微量元素的更广泛的物种。因此，我们设计了一个温室实验来模拟城市土壤中当前的铜和锌水平（分别为 102.29 毫克/千克和 148.32 毫克/千克）。该实验涉及四对入侵外来物种及其自然共存的本地物种，以研究城市土壤中必需微量元素对入侵和本地物种生长和功能特征的影响，以及它们的种间关系。结果表明，添加微量元素会削弱入侵物种的竞争力。尽管如此，微量元素的添加并没有改变竞争的结果，仍然有利于成功入侵。在微量元素添加处理下，入侵物种和本地物种仍然保持功能分化的趋势。此外，在铜处理下，入侵物种的冠面积、平均叶面积和每株叶面积比本地物种分别高 157%、177%和 178%，在锌处理下，分别高 194%、169%和 188%。此外，种间竞争使入侵物种的根生长增加了 21%，铜处理下增加了 14%，锌处理下增加了 14%。入侵物种获取光能以及吸收水分和养分的能力可能是其成功入侵的关键。
