Positive interactions between an exotic invader and moss biocrusts vary across life stage and correspond with the effect of water pulses on soil nitrogen
Positive interactions between an exotic invader and moss biocrusts vary across life stage and correspond with the effect of water pulses on soil nitrogen
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DOI：
10.1111/1365-2435.13831
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发表时间：
2021-06
影响因子：
5.2
通讯作者：
Mandy L. Slate;M. McLeod;R. Callaway
中科院分区：
文献类型：
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作者：
Mandy L. Slate;M. McLeod;R. Callaway
资源脉冲的大小和频率可以影响植物的相互作用，并增加入侵物种相对于本地物种的丰度。我们研究了在原生生物土壤结皮群落的干燥和再水化过程中产生的资源脉冲（生物结壳）形成苔藓，在生物结壳和入侵杂类，Centaurea stoebe之间的积极关联的背景下。我们调查Centaurea和生物结壳覆盖，并评估如何相互作用Centaurea，在田间试验中，生物结皮和水脉冲对植物生物量和土壤氮素的影响，并比较了矢车菊种子和生物结皮的相互作用在温室实验中，以评估与生活阶段相关的差异。在实地调查中，矢车菊和生物结壳呈正相关。在整个水脉冲处理，生物结壳生物量减少时，矢车菊被删除，表明矢车菊促进生物结壳。生物壳不影响田间的成年矢车菊，但在温室中与生物壳一起生长时，矢车菊种子生物量更大。水脉冲并不影响植物生物量，但Centaurea和生物结壳之间的相互作用对应的变化，水脉冲对土壤氮的影响并不明显，当Centaurea或生物结壳单独生长。在加入大的水脉冲24小时后，与小的水脉冲地块相比，发生生物结壳和Centaureaco的地块的土壤高9倍。在这些相同的地块中，土壤在实验结束时倾向于较低。这些结果突出了入侵外来杂类草和本地苔藓生物壳之间的积极相互作用。当两种植物共存时，水脉冲会影响土壤氮的有效性，但不会影响植物生物量，这表明资源脉冲和物种相互作用可以相互作用，影响生态系统过程。
The size and frequency of resource pulses can affect plant interactions and increase the abundance of invasive species relative to native species. We examined resource pulses generated during the desiccation and rehydration of communities of native biological soil crust (biocrust)‐forming mosses, in the context of positive associations between biocrusts and the invasive forb,Centaurea stoebe.We surveyedCentaureaand biocrust cover and evaluated how interactions amongCentaurea, biocrusts and water pulses influenced plant biomass and soil nitrogen in a field experiment.Centaureaseedling and biocrust interactions were also compared in a greenhouse experiment to evaluate differences related to life stage.In field surveys,Centaureaand biocrusts were positively associated. Across water pulse treatments, biocrust biomass decreased whenCentaureawas removed, indicating thatCentaureafacilitated biocrusts. Biocrusts did not affect adultCentaureain the field, butCentaureaseedling biomass was greater when grown with biocrusts in the greenhouse. Water pulses did not affect plant biomass, but interactions betweenCentaureaand biocrusts corresponded with variation in the effect of water pulses on soil nitrogen which were not evident whenCentaureaor biocrusts were grown alone. Twenty‐four hours after large water pulses were added, soil was nine times higher in plots where biocrusts andCentaureaco‐occurred compared with small water pulse plots. In these same plots, soil tended to be lower at the end of the experiment.These results highlight positive interactions between an invasive exotic forb and native moss biocrust. Water pulses influenced soil nitrogen availability when both plants co‐occurred, but did not affect plant biomass, suggesting that resource pulses and species interactions can interact to affect ecosystem processes.A free Plain Language Summary can be found within the Supporting Information of this article.