Afforestation Of Land Research Articles

3. Industry-Government-Academia-Private Sector Collaboration for Wood-Using Urban Development (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

3. Industry-Government-Academia-Private Sector Collaboration for Wood-Using Urban Development (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

2. Promotion of Wood Use in Cities through Cooperation with Forestry Area (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

2. Promotion of Wood Use in Cities through Cooperation with Forestry Area (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

Opening Address (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

Opening Address (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization

“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization

Panel Discussion (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

Panel Discussion (“The Epoch of Relationship between City and Forest: Reflections on the Wood-Using Urban Development” The 2019 Symposium Sponsored by “Green Fund” of the National Land Afforestation Promotion Organization)

Uso e ocupação do solo e a relação com a fragilidade dos remanescentes florestais na bacia hidrográfica do Rio Cértima/Portugal

Em Portugal, à semelhança do que ocorreu em vastas áreas da Europa Mediterrânea, ocorreram importantes mudanças no uso e ocupação do solo, sobretudo após a segunda metade do século XX. Entre essas alterações destaca-se o abandono agrícola e a florestação de terras antes ocupadas com agricultura, em consequência do êxodo rural e também de políticas públicas adotadas. Neste contexto, o presente trabalho tem como objetivo avaliar o uso e ocupação do solo, os fatores físicos (climáticos, geomorfológicos e pedológicos) e históricos e as fragilidades identificadas nos remanescentes de vegetação autóctone existentes na Bacia do Rio Cértima em Portugal. Para tal, preliminarmente foi executado um diagnóstico geral da área de estudo a partir dos seguintes geoindicadores: Bioma; Clima; Geomorfologia; Geologia; Pedologia; Hipsometria e Declividade. Em seguida, foram calculadas as métricas de paisagem divididas em três categorias: tamanho, borda e forma; e são aplicadas à bacia, em geral, considerando os remanescentes florestais mapeados. Para avaliar a qualidade da vegetação florestal existente realizou-se uma análise em campo em locais selecionados da bacia do rio Cértima, por meio do método Landscape Assessment Protocol (LAP) - Protocolo de Avaliação da Paisagem. Desta forma pode-se observar que a grande parte da cobertura vegetal existente na bacia do rio Cértima é composta por eucaliptos, sendo que foram identificados um total 1220 remanescentes florestais, que ocupam uma área de 8.547,05 ha, equivalente a 15,89% da área da bacia.

Impacts of agricultural land use change on soil aggregate stability and physical protection of organic C

Soil aggregate stability and soil organic carbon (SOC) physical sequestration is essential to regulation of anthropogenic climate change. However, relative knowledge remains elusive. The total SOC stock, aggregate stability, capacity of physically protected C, structure of macroaggregates and Al/Fe oxides under rice-wheat rotation (RW), rice-vegetable rotation (RV) and afforested land (AL) were analysed. We chose 1–2 mm macroaggregates for low-temperature ashing (LTA) treatment to mimic natural oxidation to assess the capacity of physically protected C. Using scanning electron microscopy, the N adsorption method, and energy dispersive spectroscopy, we explored the internal structure of macroaggregates under different land use types. All land use types could physically protect over 50% of SOC. AL showed the strongest capacity of C sequestration, followed by RW, which preserved 67.1% and 59.6% of SOC, respectively. After 5 h of LTA treatment, the amount of SOC removed from the macropores in cropland (RW and RV) was higher than that in AL. In micropores with further oxidation, AL and RW both lost only 5% of SOC. Fe oxides were more correlated with C dynamics than Al oxides. Free Fe oxides were associated with the easily oxidised organic matter. Soil aggregate stability significantly correlated with Al/Fe oxides (p < 0.05). The RW and AL had a greater soil aggregate stability than the RV owing to the relatively higher content of Al/Fe oxides. In conclusion, the conversion of RW to RV reduced the mechanical stability of soil aggregates and the capacity of C physical sequestration, while the conversion of RW to AL increased these two properties. Land use change affected C physical sequestration mainly via changes in surface area, pore development and the content of Fe oxides in macroaggregates.

Can changes in forest management contribute to the reduction of CO2 in the atmosphere? Literature review, discussion and Polish example

Abstract Both COP21 and COP22 stressed the role of forests in climate protection as a natural CO2 sink. With this in mind, the study reviewed some literature findings related to afforestation, stand level management, forest soils, peatland management and storage yards to increase the amount of CO2 absorbed by the forest ecosystem. It was shown that some of the assumptions, for example, afforestation or improved water relations in soils, may contribute to reduced CO2 levels in the atmosphere. Our research was of a review nature and consisted in seeking information in various scientific publications. For a better interpretation of the results, we have divided our research into several parts. In the first part, we analysed the importance of deforestation and afforestation in the context of CO2 accumulation. We discussed the results of research on these issues giving specific examples. We have analysed the possibility of afforestation of new land. Using the example of Poland, we have indicated problems related to this issue. We have analysed the possibility of afforestation of new land. On the example of Poland, we have indicated problems related to this problem. We have come to the conclusion that in today’s Europe, the obstacle to such efforts is the lack of land that can be afforested and the financial incentive to abandon farming for forestry is too low. In the second part, we discussed the role of forest stands in the process of CO2 accumulation and reduction. We discussed breeding treatments that can be performed on racks. We noticed their importance in the CO2 reduction process. We noticed that when the density of forests increased, this has a positive effect on organic carbon storage. We presented and discussed examples of different rotation strategies in the context of their impact on CO2 accumulation. We analysed issues related to obtaining wood raw material and possible further storage of coal or its release into the atmosphere. We have recognized that proper forest soil management is important for CO2 accumulation. Therefore, another part of the research was devoted to the discussion on the role of soil in the process of CO2 accumulation. We discussed examples of using soil for forest and non-forest purposes, looking for the answer: how does this affect CO2 accumulation? In addition, we analysed the impact of soil moisture on processes related to CO2 storage. In our research, we critically treated wood storage as a method of reducing CO2. We also discussed the problem of treating wood as a source of bioenergy. We came to the conclusion that wood as an energy source can have a positive effect on CO2 reduction. The condition is, however, that energy produced from wood replaces energy from fossil fuels. Finally, we presented and discussed financial and legal issues related to CO2 reduction activities involving forests. We have found that attempts to commercialize CO2 emission reduction units for emissions generated in forests should be linked to the environmental responsibility of companies, and as such, should not be included in the current emissions’ trading policies. In the article, we also present a Polish proposal to run coal farms. We discuss their importance in the context of the issues discussed in this article.

Oinez Basoa: Using school-managed afforested land for soil education in Navarre, Spain

The study of soils in secondary education is a topic of debate because it remains little considered in official curricula and programs at pre-university education, despite the increasing concern about soil in environmental studies. In this work, we present the results of a case-study conducted with a class of the 4&lt;sup&gt;th&lt;/sup&gt; grade of compulsory secondary education (10&lt;sup&gt;th&lt;/sup&gt; school year), where a didactic sequence was used that included actual data obtained in an afforestation chronosequence. The afforestation was part of the activities conducted by the network of schools to which the school belonged, with the aim of mitigating greenhouse gas emissions resulting from their annual fund-raising event. In a first step, a series of indicators related to soil and vegetation were determined in the afforested soil using a space-for-time approach with a nearby cultivated soil (corresponding to the original situation of the afforested soil) and a mature forest (similar to the target situation of the afforested land). Plant biodiversity, soil microbial biomass C and total organic C, and organic matter decomposition indicators were determined and observed to be in an intermediate situation in the afforested land between the cultivated soil and the mature forest, seven years after afforestation. In particular, an effective atmospheric C sequestration was verified from a difference of 12.41 ± 1.06 Mg of organic C per hectare in the afforested soil compared to the cultivated control. Data issued from this analysis were used to prepare a collaborative &lt;em&gt;jigsaw&lt;/em&gt;activity that was integrated into the didactic sequence designed to introduce the concepts of &lt;em&gt;ecosystem successions&lt;/em&gt; and &lt;em&gt;the carbon cycle&lt;/em&gt;. This project had a special focus on the role of soil both as a component of the ecosystem and within the carbon cycle. The success of the implementation of this sequence was tested using an initial and final test. The results of these tests showed a general improvement (42.8 points in the final test vs 23.3 in the initial test) in relation to the concepts tested. However, differences were observed in relation to the progression done by the students, which was better for ecosystems than for soil, likely as a consequence of the poor previous knowledge. From those results, we conclude that the development of educational tools that allow secondary school students to address real cases in which the soil is considered as a key component of the ecosystem can be effective in moving towards meaningful learning about soils and soil properties, since these seem still poorly understood by secondary school students.

The growth of the beech (Fagus sylvatica L.) stand on former agricultural land and its comparison with the naturally regenerated beech stand under comparable conditions

The issue of afforestation of non-forest land (e.g. agricultural land use) is currently a significant trend in land management. Sustainable development and maintenance of its ecological stability are among the reasons. The paper compares the 30-year development of the beech stand originated from artificial regeneration on former agricultural land in the area where the Ipeľ River rises in central Slovakia. Two methods of tending were used on three long-term research plots (LTPs) established at the age of 20 years: negative crown thinning, free crown thinning and the third LTP was left to its spontaneous development. The results confirmed the positive impact of tending on the development of these stands. Compared to naturally regenerated stands under comparable site conditions, their higher quantitative production was found. Regarding the qualitative production expressed by the number of trees of selective quality, the worst results were obtained on the control plot. Based on these results, it is recommended to pay more attention to the planting stock quality used for afforestation.

EUROPEAN UNION SUPPORT FOR AFFORESTATION IN POLAND – PERFORMANCE AND RESULTS

The aim of the paper is to evaluate the effects of EU support for afforestation in Poland. The research concerns afforestation measures under three subsequent Rural Development Programmes: 2004-2006, 2007-2013, 2014-2020. The examined period covers the years between 2004 and 2018. The analysis indicated that during the examined years about 80,000 ha of land were afforested. Thanks to the measure, forest area in Poland increased by 0.87%. The highest effect of the measure was achieved under RDP 2004-2006. The share of afforested area under that RDP was estimated to be at nearly 50% of total afforested area and in the case of RDP 2007-2013 at 46.7%. Under the current RDP 2014-2020, the interest of eligible agents in the measure and results are very modest. The afforested area, after five years of the financial perspective, was thirteen times lower than during three years of RDP 2004-2006. Although a rather unambitious target was set under RDP 2014-2020 – support for 82,000 ha of afforested land – small interest in new afforestation under the measure will probably be a barrier for achieving the target. The modest result is caused by a few factors, such as terms of the measure or farmer interest in different forms of support for agricultural activity.

Combined palaeolimnological and ecological approach provides added value for understanding the character and drivers of recent environmental change in Flow Country lakes

The Flow Country peatlands receive national and international recognition and protection as a highly valued habitat, and also provide a number of important ecosystem services. While there has been much research on the terrestrial peatland habitat of the Flow Country, the area’s many hundreds of natural water bodies have been largely unstudied. The first part of this study therefore focuses on establishing the contemporary conditions at 18 Flow Country lakes, examining between-lake heterogeneity in terms of physical structure, water chemistry and biological communities. Temporal change in these lakes is then considered by combining contemporary ecological and palaeolimnological approaches. We examine how the diatom and chironomid communities of Flow Country lakes have changed since a time prior to the mid-nineteenth century. Results show that the lake communities today are different to those present pre-1850, containing more taxa tolerant of increased acidity and nutrient availability. General linear modelling (GLM) analysis demonstrated a statistically significant association between the extent of change in diatom communities and both dissolved organic carbon (DOC) and nitrate. Community shifts, though considerable, are shown to be complex and idiosyncratic and no shift between trophic states is indicated. The extent and type of coarse-scale community change we observed points to widespread bottom-up drivers such as land management, afforestation and/or atmospheric deposition rather than more localised management practices such as fish stocking. The benefits of combining approaches is discussed and palaeolimnological methods by which land management, afforestation and atmospheric deposition could be further disentangled are identified.

Soil acidification of the soil profile across Chengdu Plain of China from the 1980s to 2010s

Soil acidification is a major environmental issue associated with intensive agricultural land use. Rapid urbanization has inevitably caused great changes in agricultural land use around urban areas. However, the effects of agricultural land-use change and soil parent material on the pH dynamics of the whole soil profile remain poorly understood. Based on a paired soil resampling campaign in the 1980s and 2010s, this study evaluated the effects of agricultural land-use change and parent materials on the pH dynamics of the soil profile across the Chengdu Plain of China. The results showed that soil pH significantly decreased by 1.20, 0.72, 0.66 and 0.68 units at the 0–20, 20–40, 40–60 and 60–100 cm soil depths, respectively. Conversions of traditional rice-wheat/rapeseed rotations to rice-vegetable rotations and afforested land significantly increased the magnitude of pH decline at the 0–60 cm soil depth. Soils formed from Q4 grey-brown alluvium and Q4 grey alluvium, which had a lower soil bulk density (BD) and higher sand content, showed a much higher magnitude of pH decline than soils formed from Q3 (Quaternary Pleistocene) old alluvium, and significant acidification of deep soils only occurred in soils formed from Q4 (Quaternary Holocene) grey-brown alluvium and Q4 grey alluvium. These results suggested that agricultural land-use change aggravated acidification in the soil profile and the soil acidification degrees were parent material-dependent; in particular, significant acidification of deep soils was more inclined to occur in soils with lower soil BD and higher sand content due to their effects on the downward movement of acids and the penetration resistance of plant roots. More attention should be given to minimizing or preventing acidification of both topsoil and deep soils aggravated by agricultural land-use change across urban agricultural areas.

Monitoring land-cover and land-use dynamics in Fanjingshan National Nature Reserve

Fanjingshan National Nature Reserve (FNNR) in China is a biodiversity hotspot that is part of a larger, multi-use landscape where tourism, farming, grazing, and other land uses occur. Payment for ecosystem services (PES) programs that encourage afforestation on farmlands may be important drivers of land-cover and land-use change in the region that surrounds FNNR. Our objective is to monitor and examine vegetation and land-use changes, including PES-related afforestation, between 1989 and 2017. We utilize several image processing techniques, such as illumination normalization approaches to suppress terrain effects, and multi-seasonal image compositing to minimize persistent cloud cover. Ancillary data were also incorporated to generate reliable vegetation and land-use change information. A random forest machine learning image classification routine is implemented through the cloud-based Google Earth Engine platform and refined using optimal classifier parameter tuning. Land-use transitions are identified and mapped with the implementation of stable training sites, discrete image classification, and logical land-use transition rules. Accuracy assessment results indicate our change detection workflow provides a reliable methodology to remotely monitor long-term forest cover and land-use changes in this mountainous, forested, and cloud prevalent region. We quantify the area of new built development and afforestation land and found that most of the land transitions took place in reserve buffer and its adjacent environs. For example, less than 2 km2 of new built was identified within the reserve boundary compared to 25 km2 for the entire study area between 1995 and 2016. We also shed light on the strengths and weaknesses of using Google Earth Engine for land-cover and land-use change studies. This efficient and open-access technique is important not only for assessing environmental changes and PES efficacy, but also for evaluating other conservation policies elsewhere.

Using Machine Learning to Assess Site Suitability for Afforestation with Particular Species

Judging and predicting tree suitability is of great significance in the cultivation and management of forests. Background and Objectives: Due to the diversity of tree species for afforestation in China and the lack of experts or the limitations of expert knowledge, the site rules of tree species in some regions are lacking or incomplete, so that a small number of tree suitability empirical site rules are difficult to adapt to the afforestation expert system’s diverse needs. Research Highlights: This paper explores an intelligent method to automatically extract rules for selecting favorable site conditions (tree suitability site rules) from a large amount of data to solve the problem of knowledge acquisition, updating and maintenance of suitable forest site rules in the expert system. Materials and Methods: Based on the method of site quality evaluation and the theory of the decision tree in knowledge discovery and machine learning, the dominant species of Chinese fir and Masson pine in the forest resources subcompartment data (FRSD) of Jinping County, Guizhou Province were taken as examples to select the important site factors affecting the forest quality and based on the site quality of potential productivity. Assessment methodology was proposed to determine the afforestation of a stand site by nonlinear quantile regression, the decision tree was constructed from the ID3, C5.0 and CART algorithms. Results: Finally, the best-performing CART algorithm was selected to construct the model, and the extractor of the afforestation rules was constructed. After validating the rules for selecting favorable site conditions of Chinese fir and Masson pine, the production representation method was used to construct the relationship model of the knowledge base. Conclusions: Intelligent extraction of suitable tree rules for afforestation design in an expert system was realized, which provided the theoretical basis and technical support for afforestation land planning and design.

Changes in soil phosphorus and its influencing factors following afforestation in Northern China

AbstractChanges in soil carbon (C) and nitrogen (N) stocks following afforestation have been widely studied at different scales. However, soil phosphorus (P) dynamics following afforestation are poorly understood, especially at the regional scale. This paper studied the effects of prior land use (cropland, grassland, and barren land), tree species (conifer, broadleaf, shrub, and mixed), plantation age (young, middle, and old), and climate on soil total phosphorus and available phosphorus stocks change in the top 20 cm following afforestation based on a synthesis of 50 recent publications in northern China. We also considered possible confounding effects between these factors. The results showed that, overall, soil total phosphorus and available phosphorus stocks significantly decreased by 7.3% and significantly increased by 8.8%, respectively, following afforestation. Prior land use was found to be the most important driver in determining changes in soil P stocks. Compared with a significant decrease in P of afforestation of former cropland and grassland, afforestation of barren land caused no clear decrease in P. Tree species was found to have a limited effect on changes in soil P after afforestation, and broadleaf afforestation has a lower P demand than coniferous forests in the studied region. Plantation age did not affect the dynamics of P stocks. Our results showed confounding effects of precipitation, prior land use, and tree species, which impacted the estimates of the drivers of changes in P stocks. These results highlighted the importance of tree species selection and replication across sites that receive different amounts of precipitation.

Does Caragana korshinskii plantation increase soil carbon continuously in a water‐limited landscape on the Loess Plateau, China?

AbstractAlthough afforestation of nitrogen‐fixing shrubs, especially Caragana korshinskii in semiarid areas, is expected to improve ecosystem restoration and carbon sequestration, water shortage induced by these thirsty shrubs may negate potential benefits. Yet there is poor understating of the persistence of soil carbon sequestration in nitrogen‐fixing shrub plantations. Here, we selected three C. korshinskii plantations with different ages (10, 20, and 30 years) on the Loess Plateau to evaluate the persistence of soil carbon sink. We examined dynamics of soil carbon, total nitrogen, and soil water, as well as their relationships along the plantation ages. The results showed that soil organic carbon (SOC) and soil total nitrogen (STN) were tightly coupled. SOC, STN, and soil water stocks (0–100 cm) were significantly decreased by 23.9%, 19.9%, and 29.2% from 10 to 30 years, respectively. The reduction of SOC and STN was likely caused by lowered intercanopy herbaceous productivity due to soil drying and intensified competition from shrubs. We present evidence that the positive carbon sequestration by afforestation of leguminous shrub in short term may be further weakened by water shortage, making our ability to restore degraded land in semiarid regions more challenging than previously thought. Therefore, it is essential to improve management of afforestation land such as thinning for maintaining SOC sequestration persistently in water‐limited areas.

Teores e estoques de carbono orgânico do solo em diferentes usos da terra no Planalto Sul de Santa Catarina

O estudo das modificações do carbono do solo provocadas pela mudança de uso da terra possibilita adotar medidas que reduzam os riscos de futuros impactos negativos. O objetivo da pesquisa foi quantificar e comparar os teores (COT) e os estoques (EC) de carbono orgânico total do solo em diferentes usos da terra na região do Planalto Sul de Santa Catarina. Foram selecionadas áreas sob floresta natural (FN), plantio de pinus (PP), campo natural pastejado (CP) e sucessão de lavoura e pastagem (LP). Amostras de solo foram coletadas nas camadas de 0-5, 5-10, 10-20 e 20-40 cm, onde foram determinados os teores e calculados os estoques de carbono orgânico total por dois métodos, considerando a camada equivalente e a massa equivalente de solo. Os diferentes usos da terra influenciam os COT e os EC, os quais são maiores na condição de FN. Os valores de COT foram, respectivamente, 33,9; 27,1; 26,0 e 23,2 g kg-1 para FN, PP, CP e LP, na média da camada de 0-40 cm, enquanto os EC até a profundidade de 40 cm foram, respectivamente, 121,5; 113,8; 112,4 e 100,6 Mg ha-1 com base na camada equivalente de solo e 121,5; 102,2; 99,1 e 89,8 Mg ha-1 após correção pela massa equivalente de solo. A adequada gestão de uso do solo, a recuperação de matas e a florestação das terras são passos importantes para permiti

Long-term consequences of agricultural policy decisions: How are forests planted under EEC regulation 2080/92 affecting biodiversity 20 years later?

Large-scale afforestation of agricultural land was carried out in the 1990s under the Common Agricultural Policy of the European Union. This policy aimed at delivering environmental benefits, among them positive biodiversity effects. However, knowledge of the long-term biodiversity impacts of these afforestation schemes remains very limited, particularly for insects. We provide a case study examining the biodiversity impacts of afforestation carried out in Mediterranean grasslands in southern Portugal. We sampled orthopterans and butterflies in native oak and pine plantations established under EEC regulation 2080/92, and in older exotic eucalyptus plantations. Sampling was also conducted in grassland habitats (permanent pastures and fallow land) adjacent to each plantation, and at plantation-grassland edges. In general, plantations supported lower orthopteran species richness and fewer orthopterans of conservation value than grassland and edges, particularly for eucalyptus plantations. Conversely, plantations were of higher conservation value for butterflies, and edges supported the highest butterfly richness. Plantations hosted some orthopteran and butterfly species that did not occur in grasslands, and so contributed to increase species richness at the landscape scale. Overall, results underline the importance of grassland, especially for orthopterans, and show that native plantations and associated edges can also provide habitat for species of conservation value. Therefore, retaining large grassland tracts and planting native rather than exotic tree species might minimize the negative effects of plantations for insect biodiversity in Mediterranean grassland. Overall, findings show that agricultural policy decisions can have protracted implications for biodiversity, thereby requiring long term environmental assessments and monitoring.

Variable response of inorganic carbon and consistent increase of organic carbon as a consequence of afforestation in areas with semiarid soils

AbstractSoil inorganic carbon (SIC) is the most common form of carbon in arid and semiarid regions, where afforestation is used to combat soil degradation. However, response of SIC to afforestation has been studied rarely, which hinders any prediction about soil carbon dynamics. To determine the response of SIC and soil organic carbon (SOC) to afforestation in semiarid soils and whether such responses vary with soil aggregates, soil texture, and climatic conditions, we measured SIC and SOC in bulk soils and aggregate fractions under paired afforested lands and farmlands at five sites across the Loess Plateau. The relationship of these responses to soils and climatic variables was analyzed. Afforestation increased SOC at all sites, with accumulation rates of 0.21, 0.23, 0.34, and 0.09 g kg−1 yr−1 in bulk soils, macroaggregates (&gt;0.25 mm), microaggregates (0.25–0.053 mm), and silt + clay fraction, respectively, when averaged across sites and soil depths. However, the response of SIC to afforestation varied with site, with increased SIC in drier sites and decreased SIC in wetter sites. Change in SIC was negatively correlated with change in SOC either across or within bulk soils and aggregate fractions. The SIC decreased and SOC increased with increasing soil clay content, precipitation, temperature, and site aridity index. These results indicated consistent increase in SOC but variable response of SIC to afforestation among sites in the Loess Plateau. Such variable response of SIC should be incorporated into carbon cycle models to reduce uncertainties when predicting sequestration dynamics of soil carbon.