This study investigates the long-term effects of vegetation management on nutrient concentration of various tissues and ecosystem components of 16 to 18 year-old Douglas-fir (DF), western hemlock (WH), western redcedar (WRC), and grand fir (GF) stands growing in Oregon’s central Coast Range (CR) and DF and WRC growing in Oregon’s Cascade mountain foothills (CF) under two contrasting vegetation management (VM) treatments. The treatments consist of: Control, which received no herbicide application post planting, and VM, which received five years of spring release herbicide application. Both treatments include a fall site preparation herbicide application. The ecosystem was broken down into crop trees (separated into foliage, live branches, bark, and stemwood), midstory species (separated into foliage and stem), understory, forest floor, fine roots, and mineral soil (with depth increments 0.0–0.2 m, 0.2–0.4 m, 0.4–0.6 m, and 0.6–1.0 m). All samples were analyzed for concentration of total carbon, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese, sodium, and zinc. This study design resulted in 1,740 unique nutrient concentration results being reported. The effect of VM (treatment) on tissue concentration varied by nutrient, overstory crop species (species), ecosystem component, and site. Forest floor and crop tree bark, followed by fine roots, were the ecosystem component nutrient concentrations that showed the greatest number of treatment effects across all species. Soil concentrations showed large variation across sites but were generally unaffected by treatment and species. At the CR site, magnesium and calcium soil concentrations were higher in VM plots across species, while zinc concentrations were lower. There were no other effects of treatment on soil nutrient concentrations, but there were some significant treatment × crop species interactions. Most notably, at the CF site, the concentration of C and N were higher in VM plots than control plots of DF, while the opposite was true for WRC. While total soil concentrations were generally unaffected by treatment and are unlikely to be adversely affected in the long term, it is possible that VM can reduce soil nitrogen for slow growing species like WRC.

这项研究调查了植被管理对16至18岁道格拉斯冷杉（DF），西铁杉（WH），西柳杉（WRC）和大杉树（DF）的各种组织和生态系统组成的养分浓度的长期影响。 GF）在俄勒冈州中部海岸带（CR）上生长，而DF和WRC在两种对比植被管理（VM）处理下在俄勒冈州Cascade山麓丘陵（CF）上生长。这些处理包括：对照，在种植后未施用除草剂，以及VM，在施用了春季释放除草剂的五年后。两种处理都包括在秋季现场准备除草剂。生态系统被分解为农作物树（分为树叶，活树枝，树皮和茎木），中层物种（分为树叶和茎），林下，林木，细根，和矿物土壤（深度增量为0.0-0.2 m，0.2-0.4 m，0.4-0.6 m和0.6-1.0 m）。分析所有样品的总碳，氮，磷，钾，钙，镁，硫，硼，铜，铁，锰，钠和锌的浓度。该研究设计报告了1,740种独特的营养物浓度结果。VM（处理）对组织浓度的影响因养分，过高的农作物物种（物种），生态系统组成和部位而异。森林地表和农作物树皮以及紧随其后的细根是生态系统成分的养分浓度，在所有物种中显示出最大的处理效果。土壤浓度在各个地点之间表现出很大的差异，但通常不受处理和物种的影响。在CR网站上，在整个物种的VM田中，镁和钙的土壤浓度较高，而锌的浓度较低。处理对土壤养分浓度没有其他影响，但是存在一些显着的处理×作物物种之间的相互作用。最值得注意的是，在CF场地，VM田中C和N的浓度高于DF对照田，而WRC则相反。虽然总土壤浓度通常不受处理的影响，并且从长远来看不太可能受到不利影响，但是对于慢速生长的物种，例如WRC，VM可以减少土壤氮。VM图中的C和N浓度高于DF的对照图，而WRC则相反。虽然总土壤浓度通常不受处理的影响，并且从长远来看不太可能受到不利影响，但是对于慢速生长的物种，例如WRC，VM可以减少土壤氮。VM图中的C和N浓度高于DF的对照图，而WRC则相反。虽然总土壤浓度通常不受处理的影响，并且从长远来看不太可能受到不利影响，但是对于慢速生长的物种，例如WRC，VM可以减少土壤氮。