ECOLOGY OF SURVIVAL AND RECOVERY FROM BLIGHT IN AMERICAN CHESTNUT TREES (CASTANEA-DENTATA (MARSH) BORKH) IN MICHIGAN
ECOLOGY OF SURVIVAL AND RECOVERY FROM BLIGHT IN AMERICAN CHESTNUT TREES (CASTANEA-DENTATA (MARSH) BORKH) IN MICHIGAN
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DOI：
10.2307/2996402
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发表时间：
1995-01-01
影响因子：
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通讯作者：
BREWER, LG
中科院分区：
文献类型：
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作者：
BREWER, LG
在1986-1987年间，在密歇根州的下半岛，259个地点与美国板栗树进行了检查。144个地点有板栗枯萎病的树木，而在115个地点没有枯萎病。所有地点合并有1492（75%）病树和493（25%）大于或等于10厘米胸径的无病树。在52个地点枯萎9813板栗树小于10厘米胸径被定位和检查，而在22个无枯萎病的位置4161板栗树被发现。在密歇根州的42个地点，美国板栗树有异常溃疡，并从板栗枯萎病的影响正在恢复。在这些地点建立了定量措施，以确定毒力低下的程度。在这些地点有989板栗大于或等于10厘米胸径和3233个较小的板栗。看来，最初所有的地方与异常溃疡有正常的毒性枯萎病。只有在15-25年的滞后期后才出现异常溃疡。对所有42个地点的异常溃疡和溃疡上方的活枝的百分比进行了测定，并与土壤质地进行了比较。在每个位置的13%和100%之间的溃疡是异常的。每个位置的异常溃疡上方的活枝百分比范围为41%至100%。与桑迪土壤的网站上的树木有更多的异常溃疡和更多的生存茎以上，比那些较重的质地土壤。可能的生态因素，可以解释的差异成功的弱毒力在不同的土壤类型包括：（1）一个更好的竞争优势，在排水良好的桑迪土壤，（2）弱毒力的起源，从桑迪质地的土壤，（3）更多的分散剂的弱毒力菌株在桑迪质地的土壤。
Between 1986-1987, 259 locations with American chestnut trees were examined in Michigan's lower peninsula. One hundred forty-four locations had trees with chestnut blight disease, while at 115 locations blight was not . All locations combined had 1492 (75%) diseased trees and 493 (25%) disease-free trees greater than or equal to 10 cm dbh. At 52 locations with blight 9813 chestnut trees less than 10 cm dbh were located and examined, while at 22 blight-free locations 4161 chestnut trees were found.At forty-two locations in Michigan, American chestnut trees had abnormal cankers and were recovering from the effects of chestnut blight disease. Quantitative measures were established at these locations to determine the extent of hypovirulence. At these locations there were 989 chestnut trees greater than or equal to 10 cm dbh and 3233 smaller chestnuts. It appears that initially all locations with abnormal cankers had normal virulent blight. Only after a lag of 15-25 years did abnormal cankers appear.The percentages of abnormal cankers and live branches above those cankers were determined for all 42 locations and compared to soil texture. Between 13% and 100% of the cankers at each location were abnormal. The percentage of live branches above abnormal cankers ranged from 41% to 100% per location. Trees on sites with sandy soils had more abnormal cankers and more surviving stems above them than those on heavier textured soils. Possible ecological factors which may explain the differential success of hypovirulence on different soil types include: (1) a better competitive advantage of the American chestnut on well drained sandy soils, (2) the origin of hypovirulence from sandy textured soils, and (3) more dispersing agents of hypovirulent strains on sandy textured soils.