Schwendenmann Luitgard, Michalzik Beate
School of Environment University of Auckland Auckland New Zealand.
Soil Science Institute of Geography Friedrich Schiller University Jena Jena Germany.
Ecol Evol. 2021 Mar 19;11(9):4310-4324. doi: 10.1002/ece3.7326. eCollection 2021 May.
Kauri dieback, caused by , is a biotic disturbance that poses a recent threat to the survival of kauri () forests in New Zealand. Previous studies have shown that throughfall and stemflow play an important role in the kauri forests' internal nutrient cycle. However, the effects of infection on canopy and forest floor nutrient fluxes in kauri forests remain unknown. Here, we measured throughfall, stemflow and forest floor water yield, nutrient (potassium, calcium, magnesium, manganese, silicon, sulfur, sodium, iron) concentrations and fluxes of ten kauri trees differing in soil DNA concentration, and health status. We did not observe an effect of soil DNA concentration on throughfall, stemflow, and forest floor water yield. Throughfall and forest floor nutrient concentrations and fluxes decreased (up to 50%) with increasing soil DNA concentration. We found significant effects on potassium and manganese fluxes in throughfall; calcium and silicon fluxes in forest floor leachate. A decline in canopy and forest floor nutrient fluxes may result in soil nutrient imbalances, which in turn may negatively impact forest productivity and may increase the susceptibility of trees to future pathogen infection in these ecologically unique kauri forests. Given our findings and the increasing spread of species worldwide, research on the underlying physiological mechanisms linking dieback and plant-soil nutrient fluxes is critical.
贝壳杉枯梢病由[病原体名称未给出]引起，是一种生物干扰，对新西兰贝壳杉（Agathis australis）森林的生存构成了近期威胁。先前的研究表明，穿透雨和茎流在贝壳杉森林的内部养分循环中起着重要作用。然而，[病原体名称未给出]感染对贝壳杉森林冠层和林地养分通量的影响仍然未知。在这里，我们测量了十棵贝壳杉树的穿透雨、茎流和林地产水量、养分（钾、钙、镁、锰、硅、硫、钠、铁）浓度和通量，这些树在土壤[病原体名称未给出]DNA浓度和健康状况方面存在差异。我们没有观察到土壤[病原体名称未给出]DNA浓度对穿透雨、茎流和林地产水量的影响。随着土壤[病原体名称未给出]DNA浓度的增加，穿透雨和林地养分浓度及通量下降（高达50%）。我们发现对穿透雨中的钾和锰通量、林地渗滤液中的钙和硅通量有显著影响。冠层和林地养分通量的下降可能导致土壤养分失衡，进而可能对森林生产力产生负面影响，并可能增加这些生态独特的贝壳杉森林中树木对未来病原体感染的易感性。鉴于我们的研究结果以及[病原体名称未给出]物种在全球范围内的不断扩散，研究连接枯梢病与植物 - 土壤养分通量的潜在生理机制至关重要。
