Department of Soil Science, University of Saskatchewan, 5D34 Agriculture Building, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Environ Manage. 2021 Oct;68(4):522-538. doi: 10.1007/s00267-021-01511-9. Epub 2021 Aug 2.
There is a significant knowledge gap in the area of management of the vast shelterbelt network currently existing on agricultural lands in Canada and across the world. Throughout eight decades of shelterbelt planting in Saskatchewan, Canada, there are no available records of shelterbelt management practices used by land managers, such as herbicides (H), fertilizers (F), irrigation (I), or tillage (T) applications, collectively referred to as HFIT management. The main objective of this large-scale study was to quantify the effects of HFIT management on shelterbelt carbon sequestration for six common tree and shrub species. Field data from 303 randomly selected shelterbelts across millions of hectares of agricultural land in three soil zones were combined with existing shelterbelt carbon stock curves for Saskatchewan, produced by a shelterbelt carbon management support tool, Belt-CaT, to estimate site-specific total ecosystem carbon (TEC) stocks. Estimated TEC stocks and annual rates for HFIT sites were compared to the no management sites used as a reference. HFIT management increased carbon stocks for the majority of species, four of six, resulting in higher TEC at any tree spacing, mostly at higher suitability sites. However, HFIT management effects were not consistent across individual species, land suitability, or planting designs. The top three HFIT management combinations for hybrid poplar were IT, HIT, and HI, for white spruce they were FT, IT, and FIT, and only FT benefited caragana shelterbelts. The lack of management practices makes unmanaged shelterbelts more unpredictable and unreliable, in terms of tree growth and carbon stocks sequestration potential.
在加拿大和全球范围内，农业用地上现有的大规模防护林带网络的管理方面存在着显著的知识差距。在加拿大萨斯喀彻温省长达 80 年的防护林带种植过程中，没有土地管理者使用的防护林带管理措施（如除草剂（H）、肥料（F）、灌溉（I）或耕作（T）应用）的可用记录，这些措施统称为 HFIT 管理。这项大规模研究的主要目标是量化 HFIT 管理对六种常见树木和灌木树种防护林带碳固存的影响。从三个土壤带数百万公顷农业用地上随机选择的 303 个防护林带收集的实地数据，与由防护林带碳管理支持工具 Belt-CaT 生成的萨斯喀彻温省现有防护林带碳存量曲线相结合，以估计特定地点的总生态系统碳（TEC）存量。估计的 TEC 存量和 HFIT 地点的年增长率与用作参考的无管理地点进行了比较。HFIT 管理增加了大多数物种的碳储量，六种中的四种，从而在任何树间距下都提高了 TEC，在更高适宜性的地点更为显著。然而，HFIT 管理的效果在个别物种、土地适宜性或种植设计方面并不一致。杂交杨树的顶级 HFIT 管理组合是 IT、HIT 和 HI，白云杉是 FT、IT 和 FIT，只有 FT 有利于柠条防护林带。缺乏管理措施使得未管理的防护林带在树木生长和碳储存潜力方面更加不可预测和不可靠。
