Effects of Cultural Inputs on Survival and Growth of Direct Seeded and Naturally Occurring Valley Oak Seedlings on Hardwood Rangeland
Effects of Cultural Inputs on Survival and Growth of Direct Seeded and Naturally Occurring Valley Oak Seedlings on Hardwood Rangeland
复制标题
文化投入对硬木牧场直播和自然生长的山谷橡树幼苗存活和生长的影响
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
T. Swiecki
中科院分区：
文献类型：
--
作者：
E. Bernhardt;T. Swiecki
1989年，在加利福尼亚州北部的三个地点种植了橡子，这是一个项目的一部分，该项目旨在展示使用特定地点的文化输入在硬木牧场重新放养山谷橡树的方法。使用的投入包括保护性笼子、排斥牛、覆盖、耕作和第一年灌溉。1995年，最好的处理/立地组合的成活率在80%以上，最差的处理/立地组合成活率为零，最大苗高为288 cm。在放牧的田野上，保护苗木不受牛的伤害对其生长和存活至关重要。笼养条件下放牧地幼苗的存活和生长均大于邻近非放牧地。在种植中应用景观织物和木屑覆盖物有利于幼苗的生长和/或成活。河谷栎树经常被列入橡树种植项目。本种相对容易繁殖，特别是在建立阶段有密集的文化投入。然而，对于旨在重新储存以前种植的林地的大规模种植来说，密集的投入可能昂贵得令人望而却步。此外，在一些地区补充山谷橡树可能不需要密集的投入。如果要恢复大片山谷橡树林地，土地管理者将需要确定一套文化投入，使他们能够以最低成本重新储备目标区域。1989年，我们回顾了文献，并对以前的种植进行了评估，以确定影响山谷橡树幼苗建立的因素(Swiecki和Bernhardt 1991)。利用这些信息，我们为加利福尼亚州北部的三个地点设计了示范项目。对于每个项目地点，我们确定了哪些因素最有可能限制苗木的建立和生长。然后，我们为每个项目选择了重新放养的方法，这些方法代表了不同水平的文化投入，从建立苗木所需的最低限度开始。由于每个地点存在的不同条件，在每个种植中测试的投入组合不同。我们之前报道了这些项目在种植后9个月(Bernhardt和Swiecki 1991)和18个月(Swiecki And Bernhardt 1991)的存活和生长情况。在本文中，我们报告了这些项目经过6个生长季的结果。第四个示范项目地点在自然保护协会的科苏姆内斯河保护区，被包括在最初的研究中(Bernhardt和Swiecki 1991年，Swiecki和Bernhardt 1991)。我们在本文件中不包括关于Cosumnes项目的后续数据，因为它在许多方面与其他三个地点的项目不同。
In 1989, acorns were planted at three locations in northern California as part of a project to demonstrate methods for restocking valley oak on hardwood rangeland using sitespecific cultural inputs. Inputs used included protective caging, cattle exclusion, mulching, tillage, and first-year irrigation. In 1995, survival ranged from more than 80 percent in the best treatment/site combination to zero in the worst, and maximum seedling height was 288 cm. Protection from cattle was essential for seedling growth and survival in grazed fields. Seedling survival and growth in caged sites was greater in grazed fields than in adjacent nongrazed fields. Landscape fabric and wood chip mulches applied at planting favored seedling growth and/or survival. Valley oak, Quercus lobata Nee, is frequently included in oak planting projects. This species is relatively easy to propagate, particularly with intensive cultural inputs during the establishment phase. However, intensive inputs may be prohibitively expensive for large-scale plantings intended to restock formerly wooded rangelands. Furthermore, intensive inputs may not be necessary to restock valley oaks in some areas. If large areas of valley oak woodlands are to be restored, land managers will need to identify the set of cultural inputs that will permit them to restock target areas at a minimum of cost. In 1989, we reviewed the literature and evaluated previous plantings to identify factors that affect the establishment of valley oak seedlings (Swiecki and Bernhardt 1991). Using this information, we designed demonstration projects for three locations in northern California. For each project site, we determined what factors were most likely to limit seedling establishment and growth. We then selected restocking methods for each project which represented varying levels of cultural inputs, starting from the minimum deemed necessary to establish seedlings. The combinations of inputs tested in each planting differ because of the different conditions that existed at each location. We previously reported on survival and growth at these projects 9 months (Bernhardt and Swiecki 1991) and 18 months after planting (Swiecki and Bernhardt 1991). In this paper, we report on results from these projects after 6 growing seasons. A fourth demonstration project site, at The Nature Conservancy’s Cosumnes River Preserve, was included in the original study (Bernhardt and Swiecki 1991, Swiecki and Bernhardt 1991). We do not include follow-up data on the Cosumnes project in this paper, because it differs in many respects from the projects at the other three locations.