{"title":"Microaggregates regulate the soil organic carbon sequestration and carbon flow of windproof sand fixation forests in desert ecosystems","authors":"","doi":"10.1016/j.catena.2024.108320","DOIUrl":null,"url":null,"abstract":"<div><p>Afforestation improves the soil organic carbon (SOC) sequestration by affecting aggregates formation. However, the impact of the establishment and development of windproof sand fixation forests on soil carbon (C) flow and sequestration in desert regions are largely unclear. The space-for-time method was used to elucidate changes in bulk soil, aggregate-associated organic carbon (OC) content, stock, and C flow with afforestation years and the main influencing factors. We sampled from 0–20 cm, 20–60 cm and 60–100 cm in natural desert (CK) and windproof sand fixation forests after 3, 7, and 10 years of afforestation. The direction of C flow within the aggregates was quantified using the δ<sup>13</sup>C natural abundance method. Results showed that compared to the CK, afforestation increased in the bulk soil OC stock in the 0 − 100 cm by 2.97, 5.34, and 1.67 Mg·ha<sup>−1</sup> at 3, 7, and 10 years of afforestation, respectively. The bulk soil OC content decreased gradually, but the stock increased with soil depth. Furthermore, C sequestration in this region mainly relied on the microaggregates OC. Microaggregates acted as both a “source” and a “sink” in desert ecosystems. During the 7 years of afforestation, the δ<sup>13</sup>C in the aggregates decreased with increasing soil depth, indicating older C in the subsoil. The variations in bulk soil OC stock were mainly regulated by ammonium nitrogen, nitrate nitrogen, and total nitrogen. Therefore, the results suggest that 7 years of afforestation may be the optimal choice among the three afforestation years compared for C sequestration.</p></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catena","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0341816224005174","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Afforestation improves the soil organic carbon (SOC) sequestration by affecting aggregates formation. However, the impact of the establishment and development of windproof sand fixation forests on soil carbon (C) flow and sequestration in desert regions are largely unclear. The space-for-time method was used to elucidate changes in bulk soil, aggregate-associated organic carbon (OC) content, stock, and C flow with afforestation years and the main influencing factors. We sampled from 0–20 cm, 20–60 cm and 60–100 cm in natural desert (CK) and windproof sand fixation forests after 3, 7, and 10 years of afforestation. The direction of C flow within the aggregates was quantified using the δ13C natural abundance method. Results showed that compared to the CK, afforestation increased in the bulk soil OC stock in the 0 − 100 cm by 2.97, 5.34, and 1.67 Mg·ha−1 at 3, 7, and 10 years of afforestation, respectively. The bulk soil OC content decreased gradually, but the stock increased with soil depth. Furthermore, C sequestration in this region mainly relied on the microaggregates OC. Microaggregates acted as both a “source” and a “sink” in desert ecosystems. During the 7 years of afforestation, the δ13C in the aggregates decreased with increasing soil depth, indicating older C in the subsoil. The variations in bulk soil OC stock were mainly regulated by ammonium nitrogen, nitrate nitrogen, and total nitrogen. Therefore, the results suggest that 7 years of afforestation may be the optimal choice among the three afforestation years compared for C sequestration.
期刊介绍:
Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment.
Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.