Abstract

Trees are intentionally integrated in agroforestry for numerous ecosystem services including carbon sequestration, environmental, production, and economics. Open tree growth is different from that in forests and data is limited, thus restricting integration of trees in agroforestry for optimum benefits. Growth of pin oak (Quercus palustris Muenchh.), swamp white oak (Q. bicolor Willd.), and bur oak (Q. macrocarpa Michx.) were evaluated for 24 years in an alley cropping agroforestry watershed in Northern Missouri, USA. Containerized oak seedlings were planted at 3-m spacing in the center of 4.5-m wide contour grass-legume strips established at 22.8–36.5 m intervals on a 4.44-ha watershed with a corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation. Tree height and diameter (dbh and 10-cm) were recorded. Among the three species pin oak had the greatest height, diameter at 10-cm, and dbh growth during the 24-year study. Pin oak trees showed 1.2-, 1.4-, and 1.2-times greater height, 10-cm diameter, and dbh than swamp white oak trees, the second-best species at the watershed. Biomass and carbon values of pin oak were 1.7 and 3.7 times in 2021 than swamp white oak and bur oak. Bur oak trees had the lowest height, 10-cm diameter, dbh, biomass, and carbon values among the three species. With the 3-species composition, tree biomass and carbon accumulation in a 24-year period were 22,613 and 10,854 kg ha⁻¹. Trees had > 20% tapering in the main stem. Among the three species swamp white oak had 21% tapering while pin and bur oak both had 25% tapering. All three species appear to be suitable for watershed protection while pin oak showed promising growth and greater accumulation of biomass and carbon. The study emphasizes development of agroforestry-specific tree growth models as open-grown trees differ from those in conventional forestry. This can help the selection of suitable species for enhanced ecosystem services.

中文翻译：

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橡树品种在玉米/大豆种植区的农林复合种植中开放生长，以保护流域

摘要

树木有意融入农林业，以提供多种生态系统服务，包括碳固存、环境、生产和经济。露天树木的生长与森林中的生长不同，且数据有限，因此限制了树木在农林业中的整合以获得最佳效益。在美国密苏里州北部的小巷种植农林复合流域，对针橡树 ( Quercus palustris Muenchh.)、沼泽白橡树 ( Q. bicolor Willd.) 和刺栎 ( Q. macrocarpa Michx.) 的生长进行了 24 年的评估。集装箱橡树苗以 3 米的间距种植在 4.5 米宽的轮廓草豆科带的中心，在 4.44 公顷的流域上以 22.8-36.5 米的间隔种植玉米（Zea mays L .）-大豆（Glycine max） (L.) Merr.) 旋转。记录树高和直径（dbh 和 10 厘米）。在 24 年的研究中，这三个树种中的针栎具有最大的高度、直径（10 厘米）和胸径增长。针橡树的高度、直径和胸径分别比流域第二好的树种沼泽白橡树高 1.2 倍、1.4 倍和 1.2 倍。2021 年，针橡木的生物量和碳值分别是沼泽白橡木和布尔橡木的 1.7 倍和 3.7 倍。三个树种中，柏橡树的高度、10 厘米直径、胸径、生物量和碳值最低。在3个物种的组成下，24年期间的树木生物量和碳积累量分别为22,613和10,854 kg ha ^-1。树木的主干逐渐变细> 20%。在这三个树种中，沼泽白橡树的锥度为 21%，而针橡木和布尔橡树的锥度均为 25%。所有三个树种似乎都适合流域保护，而针栎则显示出良好的生长和更大的生物量和碳积累。该研究强调开发农林业特有的树木生长模型，因为露天种植的树木与传统林业中的树木不同。这可以帮助选择合适的物种来增强生态系统服务。