Data for: Allometric relationships for eight species of 4–5 year old nitrogen-fixing and non-fixing trees

Allometric equations are often used to estimate plant biomass allocation to different tissue types from easier-to-measure quantities. Biomass allocation, and thus allometric equations, often differs by species and sometimes varies with nutrient availability. We measured biomass components for five nitrogen-fixing tree species (Robinia pseudoacacia, Gliricidia sepium, Casuarina equisetifolia, Acacia koa, Morella faya) and three non-fixing tree species (Betula nigra, Psidium cattleianum, Dodonaea viscosa) grown in field sites in New York and Hawaii for 4–5 years and subjected to four fertilization treatments. We measured total aboveground biomass, foliar biomass, main stem biomass, secondary stem biomass, and twig biomass in all species, and belowground biomass in Robinia pseudoacacia and Betula nigra, along with basal diameter, height, and canopy dimensions. The individuals spanned a wide size range (&lt;1 to 16 cm basal diameter and 0.24 to 8.8 m height). For each biomass component, abo..., ,异速生长方程（allometric equations）常被用于通过易于测定的量化指标，估算植物向不同组织类型分配的生物量。生物量分配及其对应的异速生长方程往往因物种而异，有时还会随养分有效性发生变化。本研究测定了5种固氮树种（Robinia pseudoacacia、Gliricidia sepium、Casuarina equisetifolia、Acacia koa、Morella faya）以及3种非固氮树种（Betula nigra、Psidium cattleianum、Dodonaea viscosa）的生物量组分。供试材料均于纽约与夏威夷的野外样地中定植4~5年，并接受了4种施肥处理。我们测定了所有供试树种的总地上生物量、叶生物量、主干生物量、次生茎生物量及细枝生物量；同时测定了刺槐（Robinia pseudoacacia）与黑桦（Betula nigra）的地下生物量，并记录了基径、株高与冠幅尺寸。供试个体的尺寸跨度较大：基径范围为<1~16 cm，株高范围为0.24~8.8 m。针对各生物量组分，原文后续内容截断为"abo..."。