摘要: |
资源分配与养分策略是外来植物入侵性的重要体现。为探究入侵植物的资源分配格局、吸收利用策略以及与入侵性的关系,该研究以两种菊科入侵植物假臭草(Praxelis clematidea)和金腰箭(Synedrella nodiflora)为研究对象,测定了不同入侵程度的植物构件生物量以及各器官碳(C)、氮(N)、磷(P)元素含量,分析了植物各器官N、P分配格局和化学计量特征及其与土壤营养元素的关系。结果表明:(1) 随假臭草和金腰箭入侵程度加重,土壤氮(N)、磷(P)、速效氮(AN)含量显著降低;假臭草入侵生境土壤N含量(0.70~2.7 g·kg-1)显著大于金腰箭入侵生境(0.19~0.33 g·kg-1),土壤C、P、AN和速效磷(AP)含量小于金腰箭入侵生境。(2) 三种入侵程度的假臭草和金腰箭N元素分配为叶>茎>根;P元素较多地分配至茎(假臭草)或茎和叶(金腰箭);轻度入侵的假臭草(根和茎)和金腰箭(叶)较重度入侵有低的C∶P和N∶P值,两种植物入侵初期有较快的相对生长速率;两种植物N∶P值均为叶>根和茎,其根和茎具有相对快速的生长能力。(3) 三种入侵程度的假臭草根和茎N∶P值、C∶P值小于金腰箭,金腰箭叶N∶P值、C∶P值显著小于假臭草,即假臭草根和茎具有相对快的生长速率增大入侵性,金腰箭则整体具有更快的相对生长速率,其入侵潜力更强。(4) 假臭草和金腰箭各器官N、P分配及相对生长速率分别受土壤AN、AP含量和土壤N、P含量的影响,其相对生长速率分别随土壤AN、AP、N、P元素含量的增大而加快。该研究结果对深入了解外来植物对资源分配和利用策略以及入侵潜力的预测具有指导意义。 |
关键词: 外来植物,生态化学计量学,氮磷分配,营养策略,入侵性 |
DOI:10.11931/guihaia.gxzw202304073 |
分类号: |
Fund project:国家自然科学基金(31770584);粤东入侵植物生态研究重点实验室项目(419003);广东省教育厅创新强校科研项目(2017KTSCX120) |
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Ecological stoichiometry of two Asteraceae invasive plants at different invasion degree and its influencing factors |
WANG Juhong1*, CHEN Wen2, Peng Yujiao3, CUI Xianliang4, LI Jiawei1, HUANG Longjun1
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1.School of Life Sciences and Food Engineering, Hanshan Normal University, Chaozhou 521041, Guangdong, China;2. School of Geography and Tourism, Hanshan Normal University, Chaozhou 521041, Guangdong, China; 3. Gaolan County Agricultural and Rural Bureau,Lanzhou730200,China; 4.Key?Laboratory?of?Subtropical?Medicinal?Edible?Resources?Development?and?Utilization in?Yunnan?Province/Puer?University,?Puer?665000,?Yunnan,?China
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Abstract: |
Alien invasive plants are commonly stated to pose a threat to populations of native plants, especially of endangered species. Although resource allocation and nutrient strategies are important mechanism of invasion for alien plants, surprisingly few studies have investigated whether this is the case. In order to investigate the distribution pattern, uptake and utilization strategies of invasive plants and their invasive, the carbon(C), nitrogen(N) and phosphorus(P) and biomass of the modules of invasive plant Praxelis clematidea and Synedrella nodiflora at different invasion degree from eastern Guangdong were measured, and further the ecological stoichiometry, allocation of nitrogen and phosphorus and relationship with soil factors were measured. The results were as follows: (1)The content of N element (0.70-2.7 g·kg-1) in soil of invasive habitat for P.clematidea is greater than that of S. nodiflora (0.19-0.33 g·kg-1), and while that the mean content of C, P, available nitrogen (AN), and available phosphorus(AP)for P.clematide is less than that S. nodiflora. Available nitrogen (AN) content in soil declined with increasing of invasion gradient for P.clematide, and the N, P, AN content in soil declined with increasing of the invasion gradient for S. nodiflora. (2) For two plants with different invasion degree, the N element distribution for leaves is more than stems, and than roots. The P element for P.clematide is distributed more to the stems, and for S. nodiflora to the stems and leaves. The root and stems of P.clematide, and leaves of S. nodiflora with mild invasion has low C:P and N:P values than that other invasion degrees, indicating two plants with mild invasion may have fast relative growth rate, and strong expansion potential. The C:P and N:P values in root and stems for two plants is greater than leaves, implicating that root and stems may have fast relative growth rate to increase the competitiveness of underground and above-ground. (3) The C:P and N:P values in root and stems of P.clematide at different invasion gradients is less than that of S. nodiflora, and while the C:P and N:P values in leaves of S. nodiflora is less than that of P.clematide, showing that although the root and stems of P.clematide may have faster relative growth rate, S. nodiflora has faster relative growth rate and stronger invasion potential than P.clematide. (4) The allocation of nitrogen and phosphorus, and relative growth rate of alien plant P.clematide are mainly affected by AN, AP contents in soil, that relative growth rate of organs increased with increasing of AN, AP contents in soil. The allocation of nitrogen and phosphorus, and relative growth rate of alien plant S. nodiflora are mainly affected by N and P contents in soil, that relative growth rate of organs increased with increasing of N and P contents in soil. We found some evidence that the root and stems of two Asteraceae alien species have fast relative growth rate, and further to increase the competitiveness of underground and above-ground, but their possible effect on N:P stoichiometry requires further study. |
Key words: alien species, ecological stoichiometry, allocation of nitrogen and phosphorus, nutrition strategy, invasiveness |