Phytophthora Species Detected in Two Ozark Forests with Unusual Patterns of White Oak Mortality.
Phytophthora Species Detected in Two Ozark Forests with Unusual Patterns of White Oak Mortality.
复制标题
在两片奥扎克森林中检测到的疫霉属物种，白橡树死亡模式异常。
作者：
S. Reed;J. English;R. Muzika
2011年至2017年期间，密苏里州奥扎克森林发生了白栎树（Quercus alba）的广泛衰退和死亡。症状包括迅速的树冠死亡，叶片呈青铜色，枯叶滞留，树冠枯死和变薄，以及在死亡一年内失去大树枝。衰退和死亡率与山坡排水有关，符合欧洲栎林易受致病性疫霉物种影响的描述。2014年和2015年在2个地点调查了死亡和衰退白栎树的分布情况，以及疫霉的发生和分布情况。检测到多种疫霉，包括肉桂疫霉（P. cinnamomi）、仙人掌疫霉（P. cactorum）、欧洲疫霉（P. europaea）和pini疫霉。樟树是两个样地中最常见和分布最广的物种。在白栎树基部检测到肉桂病与冠活力差无关。然而，需要更多的定量调查技术来清楚地评估这种关系。P. cinnamomi杀死北美白橡树和红橡树的细根，并与美国（俄亥俄州）和其他国家白橡树的衰落有关。需要进一步的研究来确定肉桂在奥扎克高地栎树衰退中的重要性。
Widespread decline and mortality of white oaks (Quercus alba) occurred in Missouri Ozark forests between 2011 and 2017. Symptoms included rapid crown death with bronzing of leaves, retention of dead leaves, crown dieback and thinning, and loss of large limbs within one year of death. Decline and mortality were associated with hillside drainages and fit descriptions of European oak forests predisposed to decline by pathogenic Phytophthora species. A survey was performed at two locations in 2014 and 2015 to assess the distribution of dead and declining white oaks, and the occurrence and distribution of Phytophthora species. Multiple Phytophthora species were detected, including P. cinnamomi, P. cactorum, P. europaea, and P. pini. P. cinnamomi was the most common and widely distributed species among plots at both locations. The detection of P. cinnamomi at the base of white oaks was not associated with poor crown vigor. However, more quantitative survey techniques are necessary to clearly evaluate this relationship. P. cinnamomi kills fine roots of white and red oaks in North America and has been associated with the decline of white oaks in the United States (Ohio) and other countries. Further studies are needed to determine the importance of P. cinnamomi in oak decline within the Ozark highlands.