Factors Limiting Recruitment in Valley and Coast Live Oak 1
Factors Limiting Recruitment in Valley and Coast Live Oak 1
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限制山谷和海岸 Live Oak 招募的因素 1
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
M. Hall
中科院分区：
文献类型：
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作者：
C. Tyler;B. E. Mahall;F. Davis;M. Hall
圣巴巴拉县橡树恢复计划启动于1994年，以确定限制补充的主要因素谷橡树（栎属）和海岸橡树（Q。agrifolia）。在加州州圣巴巴拉县的塞奇威克保护区，我们在4个不同年份重复了大规模种植试验，以确定牛和其他生态因素对橡树稀树草原和林地中橡树幼苗建立的影响。在33块50 × 50 m的大面积试验地中，种植了从Q. lobata)、麻栎(Q. agrifolia的网站。其中15块是对照区，开放放牧，15块使用电围栏将牛排除在外，3块在大型未放牧牧场上未放牧。在小区内，实验处理包括：1）防止小型哺乳动物（如地鼠和地松鼠），2）防止大型动物（如牛、鹿和猪），3）不防止哺乳动物食草动物。在1997年、1998年、2000年和2001年的冬天，我们种植了每种大约1,000个橡子。结果表明，在景观尺度上，小哺乳动物对种子的捕食和食草是栎幼苗更新的重要“瓶颈”。不同年份间的比较结果表明，晚冬降水不足会显著降低栎类的出苗率和成树率。受保护的橡子和幼苗的存活率在放牧和未放牧地区相当。
The Santa Barbara County Oak Restoration Program was initiated in 1994 to determine the major factors limiting recruitment of valley oak (Quercus lobata) and coast live oak (Q. agrifolia). At Sedgwick Reserve in Santa Barbara County, California, we have replicated large-scale planting experiments in four different years to determine the effects of cattle and other ecological factors on oak seedling establishment in oak savannas and woodlands. In 33 large experimental plots (50 x 50 m) we planted acorns collected from Q. lobata and Q. agrifolia on the site. Fifteen of these large plots are controls, open to grazing, fifteen exclude cattle with the use of electric fence, and three are ungrazed in large ungrazed pastures. Within the plots, experimental treatments included: 1) protection from small mammals such as gophers and ground squirrels, 2) protection from large animals such as cattle, deer, and pigs, and 3) no protection from mammalian grazers. In winters 1997, 1998, 2000, and 2001, we planted approximately 1,000 acorns of each species. Results confirm that seed predation and herbivory by small mammals are a significant “bottleneck” to oak seedling recruitment on the landscape scale. Comparing results among years indicates that lack of late winter rainfall can significantly reduce oak emergence and establishment. Survivorship of protected acorns and seedlings is comparable in grazed and ungrazed areas.