Golubiewski Nancy E
Cooperative Institute for Research in Environmental Sciences, Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309-0216, USA.
Ecol Appl. 2006 Apr;16(2):555-71. doi: 10.1890/1051-0761(2006)016[0555:uigcpe]2.0.co;2.
During the past few decades, urban and suburban developments have grown at unprecedented rates and extents with unknown consequences for ecosystem function. Carbon pools of soil and vegetation on landscaped properties were examined in the Front Range of Colorado, USA, in order to characterize vegetation and soils found in urban green spaces; analyze their aboveground biomass, vegetative C storage, and soil C storage; and compare these suburban ecosystem properties to their counterparts in native grassland and cultivated fields. Anthropogenic activities leave clear signatures on all three C compartments measured. Management level dominates the response of grass production, biomass, and N tissue concentration. This, in turn, influences the amount of C and N both stored in and harvested from sites. The site age dominates the amount of woody biomass as well as soil C and N. Soil texture only secondarily affects total soil carbon and total bulk density. Established urban green spaces harbor larger C pools, more than double in some cases, than native grasslands or agricultural fields on a per-area basis. Lawn grass produces more biomass and stores more C than local prairie or agricultural fields. Introduced woody vegetation comprises a substantial C pool in urban green spaces and represents a new ecosystem feature. After an initial decrease with site development, soil organic carbon (SOC) pools surpass those in grasslands within two decades. In addition to the marked increase of C pools through time, a shift in storage from belowground to aboveground occurs. Whereas grasslands store approximately 90% of C belowground, urban green spaces store a decreasing proportion of the total C belowground in soils through time, reaching approximately 70% 30-40 years after construction. Despite the substantial increase in C pools in this urban area, it is important to recognize that this shift is distinct from C sequestration since it does not account for a total C budget, including increased anthropogenic C emissions from these sites.
在过去几十年里，城市和郊区的发展以前所未有的速度和规模进行，对生态系统功能产生了未知的影响。在美国科罗拉多州的前缘地带，对景观化区域的土壤和植被碳库进行了研究，以便描述城市绿地中的植被和土壤特征；分析其地上生物量、植被碳储量和土壤碳储量；并将这些郊区生态系统属性与其在原生草地和耕地中的对应属性进行比较。人为活动在所有三个测量的碳库中都留下了明显的印记。管理水平主导着草产量、生物量和氮组织浓度的响应。这反过来又影响了场地中储存和收获的碳和氮的数量。场地年龄主导着木本生物量以及土壤碳和氮的数量。土壤质地仅对土壤总碳和总容重有次要影响。既定的城市绿地每单位面积的碳库比原生草地或农田大，在某些情况下是其两倍多。草坪草比当地草原或农田产生更多的生物量并储存更多的碳。引入的木本植被在城市绿地中构成了一个相当大的碳库，代表了一种新的生态系统特征。随着场地开发，土壤有机碳（SOC）库最初会减少，但在二十年内会超过草地中的碳库。除了随着时间的推移碳库显著增加外，储存还会从地下转移到地上。草地大约90%的碳储存在地下，而城市绿地随着时间的推移，土壤中地下储存的总碳比例会下降，在建成后30 - 40年达到约70%。尽管该城市地区的碳库大幅增加，但重要的是要认识到这种转移不同于碳固存，因为它没有考虑总碳预算，包括这些场地人为碳排放的增加。
