Gehring Catherine, Sevanto Sanna, Patterson Adair, Ulrich Danielle E M, Kuske Cheryl R
Department of Biological Sciences and Center for Adaptable Western Landscapes, Northern Arizona University, Flagstaff, AZ, United States.
Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM, United States.
Front Plant Sci. 2020 Oct 20;11:582574. doi: 10.3389/fpls.2020.582574. eCollection 2020.
Changing climates can cause shifts in temperature and precipitation, resulting in warming and drought in some regions. Although each of these factors has been shown to detrimentally affect forest ecosystems worldwide, information on the impacts of the combined effects of warming and drought is lacking. Forest trees rely on mutualistic root-associated fungi that contribute significantly to plant health and protection against climate stresses. We used a six-year, ecosystem-scale temperature and precipitation manipulation experiment targeted to simulate the climate in 2100 in the Southwestern United States to quantify the effects of drought, warming and combined drought and warming on the root colonization (abundance), species composition and diversity of ectomycorrhizal fungi (EMF), and dark septate fungal endophytes in a widespread woodland tree, pinyon pine ( E.). Our results show that pinyon shoot growth after 6 years of these treatments was reduced more by drought than warming. The combined drought and warming treatment reduced the abundance and diversity of EMF more than either treatment alone. Individual ectomycorrhizal fungal taxa, including the drought tolerant , were present in all treatments but the combined drought and warming treatment. The combined drought and warming treatment also reduced the abundance of dark septate endophytes (DSE), but did not affect their diversity or species composition. The current year shoot growth of the trees correlated positively with ectomycorrhizal fungal diversity, highlighting the importance of diversity in mutualistic relationships to plant growth. Our results suggest that EMF may be more important than DSE to aboveground growth in , but also more susceptible to the negative effects of combined climate stressors.
气候变化会导致温度和降水的变化，从而在一些地区引发气候变暖及干旱。尽管这些因素中的每一个都已被证明会对全球森林生态系统产生不利影响，但关于气候变暖和干旱综合影响的相关信息却十分匮乏。林木依赖与根系共生的真菌，这些真菌对植物健康及抵御气候压力起着重要作用。我们开展了一项为期六年、针对美国西南部2100年气候模拟的生态系统尺度的温度和降水调控实验，以量化干旱、气候变暖和干旱与气候变暖共同作用对一种广泛分布的林地树木——矮松（E.）的外生菌根真菌（EMF）以及深色有隔内生真菌的根系定殖（丰度）、物种组成和多样性的影响。我们的研究结果表明，经过六年的这些处理后，矮松新梢生长受干旱的影响比气候变暖更大。干旱与气候变暖共同作用的处理比单独的任何一种处理对外生菌根真菌的丰度和多样性的降低幅度都更大。包括耐旱种类在内的各个外生菌根真菌分类单元在所有处理中均有出现，但干旱与气候变暖共同作用的处理除外。干旱与气候变暖共同作用的处理还降低了深色有隔内生真菌（DSE）的丰度，但未影响其多样性或物种组成。树木当年的新梢生长与外生菌根真菌多样性呈正相关，凸显了共生关系中的多样性对植物生长的重要性。我们的研究结果表明，在外生菌根真菌对于矮松地上部分生长可能比深色有隔内生真菌更重要，但同时也更容易受到多种气候压力综合负面影响的影响。
