Berhongaray Gonzalo, Janssens I A, King J S, Ceulemans R
Department of Biology, Research Group of Plant and Vegetation Ecology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695 USA.
Plant Soil. 2013;373(1-2):269-283. doi: 10.1007/s11104-013-1778-x. Epub 2013 Jun 13.
The quantification of root dynamics remains a major challenge in ecological research because root sampling is laborious and prone to error due to unavoidable disturbance of the delicate soil-root interface. The objective of the present study was to quantify the distribution of the biomass and turnover of roots of poplars () and associated understory vegetation during the second growing season of a high-density short rotation coppice culture.
Roots were manually picked from soil samples collected with a soil core from narrow (75 cm apart) and wide rows (150 cm apart) of the double-row planting system from two genetically contrasting poplar genotypes. Several methods of estimating root production and turnover were compared.
Poplar fine root biomass was higher in the narrow rows than in the wide rows. In spite of genetic differences in above-ground biomass, annual fine root productivity was similar for both genotypes (ca. 44 g DM m year). Weed root biomass was equally distributed over the ground surface, and root productivity was more than two times higher compared to poplar fine roots (ca. 109 g DM m year).
Early in SRC plantation development, weeds result in significant root competition to the crop tree poplars, but may confer certain ecosystem services such as carbon input to soil and retention of available soil N until the trees fully occupy the site.
根系动态量化仍是生态学研究中的一项重大挑战，因为根系采样工作繁重，且由于难以避免地会扰动脆弱的土壤 - 根系界面，所以容易出错。本研究的目的是量化高密度短轮伐期矮林栽培第二个生长季期间杨树（）及其伴生林下植被根系的生物量分布和周转率。
从两种遗传特性不同的杨树基因型的双排种植系统中，用土钻采集土壤样本，人工挑选其中的根系。比较了几种估算根系生产和周转的方法。
窄行中的杨树细根生物量高于宽行。尽管地上生物量存在遗传差异，但两种基因型的年细根生产力相似（约44克干物质/平方米·年）。杂草根系生物量在地表均匀分布，其根系生产力比杨树细根高出两倍多（约109克干物质/平方米·年）。
在短轮伐期人工林发展初期，杂草会与作为作物的杨树产生显著的根系竞争，但在树木完全占据场地之前，杂草可能赋予某些生态系统服务功能，如向土壤输入碳以及保留土壤中的有效氮。
