The Effect of Vegetation Restoration in Soil Organic Carbon Storage

This review paper has been made to assess the past studies reviewed regarding vegetation restoration and its impact on soil organic carbon content. A Vegetation Restoration is an influential technique that can be used to respond to these effects. As a response to the global biodiversity crisis, more restoration actions have been taken. The European Union Council’s results on kinds of diversity after 2010 highlight words like stopping biodiversity loss and the breakdown of ecological systems in the European Union. The United Nations Conference on Biological Diversity’s growth strategy for 2022, which includes restoring at least 15% of degraded ecosystems, has made this possible. Soil types are among the most vulnerable resources on the planet due to factors such as climate change, land degradation, and the reduction of biodiversity. Organic Carbon, the top meter of soil, could potentially store three times as much carbon as is found in the air and almost twice as much as in plants. For the systematic literature review, past papers on vegetation restoration have been extracted from the latest papers of 2013 and onwards to 2022. The summary of results included key findings of the papers, the interpretation of papers reviewed, and the relevant references. Thirty papers were reviewed and selected from authentic databases and assessed that vegetation restoration significantly affects soil organic carbon (SOC). The findings also exhibit that the primary sources of prediction for SOC dynamics include changes in soil properties, quality, the number of carbon inputs, and the composition of the C pool. Vegetation restoration also plays an important role in improving the services of ecosystems such as controlling the erosion of soil and increasing the carbon sequestration. Moreover, some papers concluded that vegetation restoration positively influences on the SOC. Moreover, to increase the generalizability of the study, implications and future research indications have also been included in the end.

Water use measurement by non-irrigated Tamarix ramosissima in arid regions of Northwest China

Tamarix ramosissima Ledeb. is a typical hardy desert plant growing in arid regions of Northwest China. Sap flow in stems of Z ramosissima plants were measured continuously to determine the diurnal and seasonal variations of sap flow and to understand the water requirements of this species and the response of sap flow to meteorological factors. This article compared the sap flow rate measured by the heat balance method with the transpiration rate measured by rapid weighing, and validated that heat balance sap flow gauges were reliable for monitoring transpiration. The influence of meteorological factors on stem sap flow during the growing season was： solar radiation 〉 vapor pressure deficit 〉 air temperature 〉 rela- tive humidity 〉 wind speed. Bidirectional sap flows occurred at night, and negative sap flow generally corresponded to high atmospheric humidity. The average error in predicted sap flow rate ranged from -0.78% to 14.00% from June to September and for transpiration the average error was 8.19%. Therefore, based on the functional equations between sap flow and meteorological factors as well as sapwood area, transpiration of an individual plant, and even the stand-level transpiration, can be estimated accurately through extrapolation.

Redistribution process of precipitation in ecological restoration activity of Pinus sylvestris var.mongolica in Mu Us Sandy Land,China

Precipitation is the most important water resource in semi-arid regions of China.The redistribution of precipitation among atmospheric water,soil water and groundwater are related to the land surface afforested ecological system.The study took widely replanted Pinus sylvestris var.Mongolica(PSM)in Mu Us Sandy Land(MUSL)as a research object and monitored precipitation,soil moisture,sap flow,and deep soil recharge(DSR)to find out moisture distribution in shallow soil layers.Results showed that the restoration process of PSM in MUSL changed the distribution of precipitation,with part of it infltrating downward as DsR and part of it being stored in the shallow soil.Consequently,evapotranspiration increased and DsR significantly decreased,resulting in up to 466.9 mm of precipitation returning to the atmosphere through evapotranspiration in 2016.Vegetation increased soil water storage(SwS)capacity,with maximum SWS in PSM plot and bare sandy land(BSL)being 260 mm and 197 mm per unit horizontal area,respectively in 2016.DSR decreased from 54%of precipitation in the BSL plot to 0.2%of precipitation in the PSM plot in 2016.A great portion of infiltrated water was stored in the PSM ecosystem,resulting in a time lag of infiltration to reach the deep soil layer,and the infiltration rate in the BSL plot was 11 times of that in the PSM plot.SWS decreased 16 mm and 7.6 mm per unit horizontal area over a one-year period(from March to October,non-freezing time)in 2017 and 2019,respectively.The PSM annual sap flow was maintained at a relatively constant level of 154 mm/yr.Through in-situ measurement and comparative analysis of the precipitation redistribution of the BSL plot and the PSM plot,we find that PSM can significantly reduce the shallow soil water storage and DSR.However,substantial reduction of shallow soil water storage and DsR is detrimental for the long-term development of PSM forest.Therefore,it is necessary to reduce PSM density to cut the water consumption by PSM per unit area,thus to augment the shallow SWS and DSR,which will be beneficial for the PSM to survive under extreme drought conditions in the future.This study helps us understand the role of precipitationinduced groundwater recharge in the process of vegetation restoration in semi-arid regions and explains thepossiblecauses of PSM forest degradation.