Annual Carbon Storage Research Articles

Influence of stand characteristics and management activities on aboveground carbon storage in Japanese cedar and cypress plantations: Sustainable management implications

Tree plantations substantially sequester carbon in aboveground biomass and soil and serve as an alternative to forests in mitigating global warming. This study investigated the relationship between aboveground carbon and stand characteristics and management activities in two Japanese plantations (cedar and cypress) for their sustainable management viewpoint, which has not been studied before. Aboveground carbon stock ranged from 3.96 to 248.53 Mg C ha-1 in 9- to 188-year-old Japanese cedar and 7.09 to 119.17 Mg C ha-1 in 11- to 129-year-old Japanese cypress plantations. Annual aboveground carbon storage differed significantly between the two species. Aboveground carbon storage in Japanese cedar was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand and clay, site quality, and stem density) and management activities (e.g. initial silvicultural practices, stem exclusion practices, pest and wildlife management and land management). However, the same in Japanese cypress was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand, bulk density, site quality, stem density, and elevation) along with management activities (e.g. initial silvicultural practices, stem exclusion practices and land management). Therefore, continuous monitoring and periodic assessment of the stand characteristics and management activities may be taken into consideration in future policy-making decisions to promote aboveground carbon storage and climate change mitigation ability of these plantations in Japan on a sustained basis.

Spatio-temporal dynamics of net primary productivity and the economic value of Spartina alterniflora in the coastal regions of China

This study employs an improved Carnegie–Ames–Stanford Approach (CASA) model to calculate the Net Primary Productivity (NPP) of Spartina alterniflora (SA) and various other land use/land cover types (LULC) across coastal China over multiple years. The research aims to provide significant theoretical and practical insights into carbon sink research in coastal zones, sustainable development, and resource management. Key findings include identifying the first εmax value of 2.219 g C/MJ for SA, addressing a critical data gap in CASA modeling research on invasive plants. SA's NPP exhibited higher values in Shanghai and Zhejiang due to factors such as genetic diversity, invasion duration, and tidal dynamics. In contrast, other LULC exhibited higher NPP values in southern and inland regions, characterized by greater vegetation cover and favorable growing conditions. In 2020, SA and other LULC sequestered 16.352 kt C and 0.821*106 kt C, respectively. From 2000 to 2020, the average annual NPP and total carbon storage of SA and other LULC increased significantly, primarily driven by Shanghai and deciduous needleleaf forests, respectively. Seasonal NPP trends followed summer> spring> autumn> winter, influenced by climate conditions and plant life activities. Economic assessments in 2020 estimated SA's carbon storage value at RMB0.409 billion (Market Value method) or RMB5.562 billion (Carbon Tax method), with RMB2.054 billion attributed to oxygen release values, underscoring its economic and ecological potential. Among other LULC, evergreen broadleaf forests showed the highest carbon storage value (RMB183.463 billion). The study emphasizes the critical role of all LULC in carbon storage and oxygen release, advocating for targeted conservation and land management strategies. It suggests that managing SA should balance stringent control in high-risk areas, lenient measures in low-risk areas, eradication of scattered populations, and maximizing ecological benefits in retention areas, with continuous monitoring and adaptive management strategies to balance conservation and development efforts.

Ecosystem services dynamics and their influencing factors: Synergies/tradeoffs interactions and implications, the case of upper Blue Nile basin, Ethiopia

Understanding the relationships among ecosystem services (ESs) and their interactions with influencing factors is essential for spatially targeted ecosystem governance. However, classifying the spatial distribution of these diverse interactions still needs improvement. Furthermore, existing studies have insufficiently addressed the specific impacts of bidirectional land cover transitions on ESs. Taking the upper Blue Nile basin as a study area, we estimated the spatiotemporal distribution of annual water yield (AWY), carbon storage (CS), habitat quality (HQ), and soil retention (SR) from 2000 to 2020, using InVEST models and associated formulas. Changes in ESs per inward-outward land cover transition were quantified based on the Cross-Tabulation Matrix. An improved pairwise method was employed to assess the spatially diverse interactions between ESs pairs and their relationship with influencing factors. The statistical significance of influencing factors was evaluated using partial least square regression. The findings indicated that high HQ values were prevalent in the west, while they were in the east for SR. The central and southern areas experienced higher CS and AWY values. During the study period, variations were observed in the mean values of SR (ranging from 22.89 to 23.88 × 102 t/ha/y), AWY (32.13–42.2 × 102 mm/ha/y), CS (90.5–102.9 × 103gC/ha/y) and HQ (0.62–0.64). Synergies were predominant in AWY-CS, AWY-SR, and CS-SR pairs. HQ revealed more of a no-effect and tradeoff relationship with other ESs. The interactions between ESs and influencing factors were dominated by synergies, followed by tradeoffs and no-effect. The influence of landscape structure (gyrate and landscape shape index) and land surface temperature on all ESs and precipitation on AWY and SR was significant (1.049 ≤ Variable Importance in the Projection ≤ 1.371). Overall, the spatiotemporal dynamics of key ESs and the modeling of their drivers are essential policy information for taking spatially explicit conservation measures. This study will also serve as a valuable methodological reference for future research.

Tracking annual dynamics of carbon storage of salt marsh plants in the Yellow River Delta national nature reserve of china based on sentinel-2 imagery during 2017–2022

Coastal salt marshes play a key role in coastal carbon sequestration. Understanding the spatial distribution and annual changes of carbon storage of salt marsh plants at a local scale is helpful for accurate protection and restoration. However, the annual carbon storage of salt marsh plants has not yet been obtained in the Yellow River Delta National Nature Reserve (YRDNNR), China. Here, we developed a fast and reliable method to produce an annual map of carbon storage of herbaceous salt marsh plants from 2017 to 2022 based on multi-year in situ data and 10-meter resolution Sentinel-2 images in YRDNNR. That is, a deep belief network based on conjugate gradient (CGDBN) pixel-level classification, a generative adversarial network with a constrained factor (GAN-CF) measured sample expansion and multiple linear regression (MLR) quantitative inversion algorithm is used. The results showed that: (1) The carbon storage of herbaceous salt marsh plants in the YRDNNR increased in 2017–2018 and 2019–2021, with an average carbon storage dynamic of 4.53–8.39 Mg/ha. (2) In 2021, the area of salt marsh vegetation increased significantly by 20 % compared to 2017. Although its area decreased sharply due to the removal of invasive species (S. alterniflora) in 2022, the carbon storage per unit area of salt marsh plants remained at 7.77 Mg/ha. (3) The carbon storage of salt marsh vegetation showed a gradient change along the community succession from land to sea. Estimating annual carbon storage of salt marsh plants could provide basic data for recognizing the ‘blue carbon’ contribution of coastal plants and managing the coastal salt marsh ecosystem in Yellow River Delta.

Study on the water-carbon coupling coordination function on the eastern edge of the Qinghai-Tibet plateau

The Qilian Mountains on the eastern edge of the Tibetan Plateau are an important ecological security barrier in northwestern China and an extremely critical water-carbon conservation area. The water and carbon cycles are closely linked, and the water-carbon coupling process has become further complicated under global climate change and through the intensification of human activities. A better understanding of the impacts and potential mechanisms of water-carbon interactions is the key to improving the efficiency of water-carbon resource utilization. To rationalize the relationship between water and carbon, we used data from statistical almanacs, land use, DEM and various climatic elements to estimate the water-carbon nutrition in the Qilian Mountains from 2000 to 2020 based on the InVEST model and the Coupled Coordination Degree Model (CCDM) and to explore the coupling mechanism of water-carbon, spatial-temporal dynamics, and the influencing factors. The results showed that: 1). the average annual water and carbon storage in the Qilian Mountains are 63.21 × 108 m3 and 77.82 × 107 t, respectively, showing a spatial distribution pattern of high in the northeast and low in the southwest. The inter-annual changes in water (y=-0.451x+968.920) and carbon (y = 0.082x-87.808) showed different trends. 2). The annual average of the water-carbon coupling coordination degree of 0.280 in the Qilian Mountains was low in general, and the trends declined over time from 0.273 in 2000 to 0.264 in 2020. However, the spatial distribution was relatively clustered, and the spatial correlation improved from 0.69 in 2000 to 0.74 in 2020. 3). Precipitation, potential evapotranspiration and temperature were important elements driving water-carbon coupling. Among them, precipitation was significantly positively correlated with water-carbon coupling (r = 0.88), and potential evapotranspiration (r=-0.56) and temperature (r=-0.39) showed significant negative correlations with water-carbon coupling. This study can provide information for management and decision-making in carbon sequestration, water resource utilization, ecological protection and climate change, and promote the study of the spatial and temporal coupling functions of water and carbon with in the Qilian Mountains. Meanwhile, this study can provide a reference for the environmental management and protection of the Qilian Mountain ecosystem.

Climate and scale are critical for illustrating the links between carbon and water services across Qinghai-Tibet plateau

Carbon storage (CS) and water yield (WY) are crucial for the ecological sustainability of ecosystem services (ESs). While the relationship between these services has been debated globally and regionally, climate change has limited our understanding of their relationship and the factors affecting them, particularly in high-altitude regions. We used multi-source data and remote sensing models to determine annual CS and WY in the Qinghai-Tibet Plateau (QTP) from 2000 to 2018 with high spatial accuracy. The results show that the highest values of these services are concentrated in the southern and eastern QTP where forests are prevalent. CS and WY increased significantly in the south, with mean annual temperatures (MAT) positively affecting CS, but MAT negatively impacts CS in the northern plateau. The relationship between CS and MAT was stronger than that of CS and mean annual precipitation (MAP), which was a major driver of WY. Although the relationship between CS and WY increased in the plateau over 18 years, it was found to be dependent on spatial scale. This study highlights the importance of considering climate change and the scale effect when examining the changes in carbon and water services in the promotion of ecological sustainability.

Aboveground live tree carbon stock and change in forests of conterminous United States: influence of stand age

BackgroundSequestration of carbon on forest land is a common and practical component within many climate action plans developed by state or municipal governments. Initial planning often identifies the general magnitude of sequestration expected given the scope of the project. Because age plays a key role in forest carbon dynamics, we summarize both the carbon stock and accumulation rates in live trees by age class and region, allowing managers and policymakers to assess the influence of forest age class structure on forest carbon storage as represented in current inventories. State-level information is provided in supplementary tables.ResultsAverage regional aboveground live tree carbon stocks (represented on a per area basis) range from 11.6 tC/ha in the Great Plains to 130 tC/ha in the Pacific Northwest West (west-side of Cascades) and increase with age in all regions, although in three regions carbon stock declined in the oldest age class. Regional average annual net change in live aboveground tree carbon varies from a low of − 0.18 tC /ha/yr in the Rocky Mountain South region to a high value of 1.74 tC/ha/yr in Pacific Northwest West. In all regions except Rocky Mountain South, accumulation rates are highest in the younger age classes and decline with age, with older age classes in several western regions showing negative rates. In the Southeast and Pacific Northwest West, intermediate age classes exhibit lower rates, likely due to harvesting activity.ConclusionsAboveground live tree carbon stocks increase and rates of average change decrease with age with few exceptions; this pattern holds when examining hardwood and softwood types individually. Because multiple forest management objectives are often considered and tradeoffs need to be assessed, we recommend considering both measures—standing stock and average annual change—of carbon storage. The relative importance of each component depends on management and policy objectives and the time frame related to those objectives. Harvesting and natural disturbance also affect forest carbon stock and change and may need to be considered if developing projections of potential carbon storage. We present forest carbon summaries at a scale and scope to meet information needs of managers and policymakers.

Uma estimativa dos serviços ecossistêmicos fornecidos pelas florestas urbanas e peri-urbanas: um estudo de caso em Juiz de Fora, Brasil

ABSTRACT: Urban expansion has led to the replacement of natural landscapes and environmental degradation, making cities and their urban and peri-urban forests (UPFs) vulnerable to climate change, especially on the formation of heat islands. Using i-Tree Canopy program (v. 7.0), we estimate the ecosystem services provided by UPFs in Juiz de Fora (Minas Gerais State, Southeastern Brazil), through the analysis of the (1) annual removal of atmospheric pollutants, (2) annual removal of atmospheric carbon, (3) total carbon stock in vegetation, and (4) the monetary benefits of sequestered and stocked carbon, based on Future Carbon Credit (CFI2Z1) as a monetary proxy. The results showed an average total amount of removal of 4.45 thousand tons of air pollution annually. The average annual total carbon storage was 158 thousand tons and the equivalent CO2 was 580 thousand tons, with an estimated total value of R$ 173 million per year. Significant values of the gross carbon stock (3.98 million tons) and equivalent CO2 (14.59 million tons) were found, being valued at R$ 4.35 billion. We concluded that the Juiz de Fora UPFs have a great potential for socio-environmental and economic benefits.

Assessing and Characterizing Carbon Storage in Wetlands of the Guangdong–Hong Kong–Macau Greater Bay Area, China, During 1995–2020

Wetland carbon storage plays an essential role in the global carbon cycle. However, in recent decades, intensive human activities and rapid urbanization have reduced wetland C stocks in the Guangdong-Hong Kong-Macau Greater Bay Area (GBA). Long-term assessment of carbon storage in the wetland ecosystems of the GBA is needed for promoting regional sustainable development. Therefore, we proposed a framework integrating the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) model and water inundation frequency, which was retrieved via multiple index water detection rule (MIWDR) based on Google Earth Engine platform, to estimate yearly carbon storage in wetlands across the GBA at a 30-m spatial resolution during 1995&#x223C;2020. The incorporation of water inundation frequency in estimating carbon storage in wetlands presents features of long time series and higher temporal frequency. The results showed that: (1) the carbon storage of wetlands estimated by the InVEST model decreased from 33.38 Tg&#x00B7;C to 16.64 Tg&#x00B7;C between 1995 and 2020 in the GBA, mainly owning to the loss of paddy fields. (2) There is a significant exponentially decreasing relationship between water inundation frequency and carbon storage density within the potential wetland extent, with the <i>R²</i> reaching 0.998, which denotes huge potential for estimating wetland carbon storage; (3) annual wetland carbon storage estimated were divided into three main stages: a rapidly increasing period (1995-2004), a falling period (2005-2013) and a slightly fluctuating period (2015-2020). This research may provide references for supporting decision-making in implementing wetland-related sustainable development and carbon-neutrality policies in the GBA.

Ecophysiology of an urban citrus orchard

Characterizing the carbon and water economy of non-commercial urban citrus orchards can help determine their value in urban settings. This includes provisions of urban ecology and ecosystem services, such as shade, conservation of biodiversity, and carbon sequestration, under space and water limitations that may be particularly suitable in the semi-arid Mediterranean regions. We carried out canopy-scale eddy covariance (EC) measurements of net ecosystem CO2 exchange (NEE) and evapotranspiration (ET), partitioned these fluxes to their components using chamber-based soil fluxes, and combined them with carbon stock to provide a first approximation of the apparent ecosystem carbon turnover rate (τeco). The urban orchard switched from a carbon sink of 0.6 μmol m−2 s−1 to a carbon source of 0.2 μmol m−2 s−1 between winter and summer, with a first approximation of the annual carbon storage capacity of ∼75.3 g m−2 and a total carbon accumulation over its 40 year life span of ∼3014 g m−2. Carbon accumulated predominantly below ground (67 % of total), and soil CO2 effluxes showed low sensitivity to temperature (Q10 ∼1.6) and therefore also to climate warming, but also a fast C turnover rate (∼5.4 y), and therefore sensitivity to disturbances. The rates of ET increased from 0.40 to 1.25 mmol m−2 s−1 between the wet and dry seasons, and was ∼50 % of a similar nearby commercial orchard. Partitioning of the ecosystem carbon and water fluxes indicated high canopy water use efficiency (11.7 μmol CO2/mmol H2O; during the peak activity period). We demonstrate the potential of urban citrus orchards with low supplemental irrigation (50 % compared with commercial orchards in the area) to store significant amounts of carbon with high transpiration efficiencies. The results will help decision making in regard to urban tree planting and the ecological management of urban green spaces and community use in water-limited environments.

Annual Growth Progression, Nutrient Transformation, and Carbon Storage in Tissues of Cunninghamia lanceolata Monoculture in Relation to Soil Quality Indicators Influenced by Intraspecific Competition Intensity

Annual Growth Progression, Nutrient Transformation, and Carbon Storage in Tissues of Cunninghamia lanceolata Monoculture in Relation to Soil Quality Indicators Influenced by Intraspecific Competition Intensity

Multi‐Decadal Carbon Cycle Measurements Indicate Resistance to External Drivers of Change at the Howland Forest AmeriFlux Site

AbstractA long‐standing goal of ecology has been to understand the cycling of carbon in forests. This has taken on new urgency with the need to address a rapidly changing climate. Forests serve as long‐term stores for atmospheric CO2, but their continued ability to take up new carbon is dependent on future changes in climate and other factors such as age. We have been measuring many aspects of carbon cycling at an unmanaged evergreen forest in central Maine, USA, for over 25 years. Here we use these data to address questions about the magnitude and control of carbon fluxes and quantify flows and uncertainties between the different pools. A key issue was to assess whether recent climate change and an aging tree population were reducing annual C storage. Total ecosystem C stocks determined from inventory and quantitative soil pits were about 23,300 g C m−2 with 46% in live trees, and 48% in the soil. Annual biomass increment in trees at Howland Forest averaged 161 ± 23 g C m−2 yr−1, not significantly different from annual net ecosystem production (NEP = −NEE) of 211 ± 40 g C m−2 y−1 measured by eddy covariance. Unexpectedly, there was a small but significant trend of increasing C uptake through time in the eddy flux data. This was despite the period of record including some of the most climate‐extreme years in the last 125. We find a surprising lack of influence of climate variability on annual carbon storage in this mature forest.

Spatiotemporal patterns and driving factors of carbon dynamics in forest ecosystems: A case study from Turkey.

Evaluating the spatiotemporal patterns of carbon dynamics is critical for both understanding the role of forest ecosystems in the carbon cycle and developing effective forest policies to mitigate the impacts of climate change. This study analyzes the effects of spatiotemporal changes on carbon dynamics based on landscape structure for the Hisar Planning Unit, Turkey, using forest inventory data between 1973 and 2015. The total carbon stock increased from 1434.49 Gg in 1973 to 1919.37 Gg in 2015, an increase of 33.8%. The mean annual carbon storage was 11.54 Gg · year-1 , including 4.28 Gg · year-1 in biomass and 7.26 Gg · year-1 in soil over four decades. The most significant carbon pool in the total carbon stock was from the soil, with 71.6%, 70.7%, and 69.4% of the total carbon storage in 1973, 1998, and 2015, respectively. Pure pine stands, overmature development stages, fully covered stands, and older forests were the prevailing factors affecting carbon density. The conversion from degraded (1442.47 ha, 14.85%), coppice (157.04 ha, 3.9%), and non-forest lands (1412.91 ha, 5.2%) to productive forests with afforestation or restoration activities significantly boosted the total carbon storage. Furthermore, increasing awareness and stewardship in forest management coupled with improved economic well-being reduced the pressure on the forests, leading to an increase in the quality of forest structure. These changes in landscape structure resulted in the heterogeneous distribution of carbon dynamics. In conclusion, understanding the spatiotemporal patterns of carbon dynamics is crucial for both forest managers and policy-makers in developing sustainable forest management practices and climate mitigation strategies for ecological sustainability and climate-smart forestry. Integr Environ Assess Manag 2022;18:209-223. © 2021 SETAC.

Carbon Storage Potential of a Waterlogged Agroforestry System of Tripura, India

The present study reports the potential of carbon (C) storage in traditional agroforestry systems (i.e., a set of age-old agroforestry systems) under waterlogged environmental conditions from north-eastern India. An experiment was conducted in a farmer’s field and further used CO2FIX model, allometric equations, and destructive sampling methods to know the potential of C sequestration. In this study area, agroforestry system is dominated by woody perennials like Areca catechu, Cocos nucifera, Mangifera indica, Artocarpus heterophyllus, Melocanna baccifera, and Colocasia esculenta as annual crop component. Need-based management of the drainage system has been built-up by making broad/narrow bunds for maintaining water levels at different stages of plant growth. The total annual carbon storage potential of this traditional agroforestry system was estimated as 103.760±8.630 t ha−1year−1. The highest annual carbon storage potential (97.900±8.090 t ha−1year−1) was recorded in annual crop components (i.e., Colocasia) followed by trees and its underlaid soil (4.250±0.340 t ha−1year−1) and lowest for bamboos (1.610± 0. 200 t ha−1 year−1). However, the estimated carbon stored, annually, was 24.992±1.502 t ha−1 year−1 in which Colocasia share maximum contribution (19.600±1.080 t ha−1 year−1) followed by trees + soil (3.798±0.229 t ha−1 year−1) and the minimum contribution from bamboos (1.594±0.193 t ha−1 year−1). Moreover, total carbon loss from harvesting of this system was 78.768±7.128 t ha−1 year−1. The study, therefore, recommends this agroforestry system for other waterlogged ecosystems at regional and/or global scale under a warm per-humid climate for both livelihood opportunities and environmental sustainability.

Assessment of Annual Shoot Biomass and Carbon Storage Potential of Grewia optiva: an Approach to Combat Climate Change in Garhwal Himalaya

Climate change is major challenge in modern era and requires key attention to the researcher, globally. Carbon (‘C’) sequestering through agroforestry is one of the ways to mitigate the carbon reduction and provide safeguards to the environment for livelihood. The present study was conducted on Grewia optiva tree which is dominated in agroforestry systems of Tehri Garhwal Himalaya (Uttarakhand) in different villages at three altitudes, i.e., upper altitudes (UA), middle altitude (MA), and lower altitude (LA) ranged from 500 to 1500 m amsl. Soil moisture, water holding capacity (WHC), bulk density (BD), and soil organic carbon (SOC) reported highest in LA compared to MA and UA, which might be because of all eroded material deposited in LA . Further, nitrogen storage in UA is higher due to comparatively low temperature significantly lower the microbial activities for N2O emission than MA and LA. The low nitogen in LA might be due to higher nitrification and/or denitrification rate. The same also supported by low carbon content (energy sources to microbial activity) in LA. The density of Grewia optiva in agroforestry was high in LA; however, total tree carbon was highest in MA (20.8 t/ha) followed by UA (20.4 t/ha) and LA (19.1 t/ha) while annual shoot carbon was highest in LA (2.43 t/ha) followed by MA (1.08 t/ha) and UA (0.77 t/ha). Further, carbon credit likely to be earned from the agroforestry under G. optiva is estimated as 553,702 Euro. Therefore, Grewia optiva is strongly recommending for agroforestry which will further help in socioeconomic development and carbon-reducing strategies in mitigating future climate.

Evaluation of the carbon accumulation capability and carbon storage of different types of wetlands in the Nanhui tidal flat of the Yangtze River estuary.

Wetlands are carbon pools for terrestrial ecosystems and play an important role in the global carbon cycle. The Nanhui tidal flat is located at the Yangtze River estuary and has been disturbed by various human activities. However, the effect of human activities on the carbon accumulation capability and carbon storage of wetlands in the Nanhui tidal flat is poorly understood. In this study, the annual carbon accumulation capability and carbon storage of three types of Spartina alterniflora Loisel. wetlands in the Nanhui tidal flat, which were defined as a natural wetland, silt-promoting wetland, and artificial restored wetland, were evaluated by analyzing the plant carbon fixation capability, soil carbon emissions, and soil organic carbon (SOC) density. The results showed that the three wetlands all had a carbon sink effect and the natural wetland, artificial restored wetland, and silt-promoting wetland annually accumulated 7.94, 7.14, and 6.33 kg m-2 CO2, respectively. The existing SOC density in the subsurface soil (0-40 cm) in the natural wetland, silt-promoting wetland, and artificial restored wetland was 23.26, 17.95, and 12.21 kg m-2 CO2, respectively. The natural wetland, with no human disturbance, had a longer duration of waterlogging and greater tidal nutrition inputs than the other wetlands, resulting in a higher plant biomass and lower soil respiration (SR). It therefore had the strongest carbon accumulation capability and highest SOC storage.

Identification of the priority conservation areas of national park: A case study of Lishui City, Zhejiang Province, China

It is the goal of protected area management to make full use of limited resources to better protect biodiversity. Currently, the main tasks of developing national park system in China are to combine conservation features, optimize the spatial network of protected areas, and identify the prio-rity conservation areas of national parks effectively. In this study, we assessed the spatial distribution of key ecosystem services (carbon sequestration, oxygen release, hydrological regulation, water resources, and soil retention) using ecological model, and simulated the distribution of suitable habitats for 37 endangered species by MaxEnt in Lishui City, Zhejiang Province. The irreplaceability index of each planning unit in Lishui was calculated on the 0.4 km×0.4 km grid using the systema-tic conservation planning model (MARXAN), setting key ecosystem services and endangered species as the conservation objects. Combined with the local management needs, the priority protection areas of national parks were identified comprehensively. The results showed that during 2005 to 2015, the annual carbon storage, oxygen release, hydrological regulation, water resource, and soil retention in the study area was 0.05 kg C·m-2·a-1, 0.13 kg O2·m-2·a-1, 83.25×108 m3·a-1, 803 mm·a-1, and 95.53 t·hm-2·a-1, respectively. The irreplaceability index of different land use types was significantly different. The irreplaceability index of forest, river and reservoir, garden, cultivated land, residential land was 50-100, 60-100, 30-50, 15-35, 0-25, respectively. The priority conservation areas accounted for 11.8% of the study area. This study put forward a systematic conservation planning idea combining biodiversity and ecosystem services, which could provide a useful framework and technical support for optimizing the network layout of protected areas and priority conservation areas of national parks, and help to enhance the overall effectiveness of the establishment of the protected areas system with national parks as its main type in China.

CARBON POOLS IN OLD-GROWTH SCOTS PINE STANDS ON ORGANIC SOILS AND ITS CONCENTRATION IN DEADWOOD: CASES STUDY IN LATVIA

Carbon sequestration is crucial to mitigate climate changes, therefore it is important to have accurate estimates of carbon pools in the forest. So far, data on carbon pools in old-growth forests are very scarce, therefore aim of the study was to assess the carbon pools in old-growth Scots pine stands on organic soil and carbon concentration in deadwood of different decay classes in Latvia. Carbon content in deadwood was test in samples, collected in 26 randomly selected over mature, unmanaged stands across Latvia (five samples per decay class and tree species). Carbon pools were assessed in 38 sample plots (size 500 m2) in five Scots pine stands on wet organic soil (Caricoso- phragmitosa forest type) at the age of 167 to 203 years. Mean carbon concentration in deadwood across all species and decay classes was 46.6±1.57%. For aspen it did not change with progressing decay was found, but increase was observed for Scots pine, Norway spruce and birch. For these species difference in concentration between first three (more fresh) and last two decay classes (mean 45.9±0.9% and 49.9±1.6%, respectively) was statistically significant. Old-growth Scots pine stands on peat soils had rather large amount of deadwood: 100.6 ± 74.7 m3ha-1. However, its share in total carbon storage (290.0 ± 57.9 t ha-1) was small and most of carbon (57%) was found in soil. Mean annual carbon storage in tree biomass and deadwood decreased with stand age; its absolute value was similar in over-mature and mature (101-120 years) stands.

Changes in carbon stocks of soil and forest floor in black pine plantations in Turkey

The objectives of this study were: (1) to determine carbon stock changes in the soil and forest floor of black pine (Pinus nigra subsp. pallasiana) plantations in Turkey; (2) to determine the effects of thinning on annual carbon accumulation in both; and, (3) to investigate relationships between annual carbon storage in soil and forest floor and stand characteristics of black pine. Samples were taken in 90 plots from stands at the pole (dbh = 11.0–19.9 cm) and sawlog (dbh = 20.0–35.9 cm) stages. Carbon analyses of soil and forest floor samples showed that in unthinned plantations significant organic carbon was sequestered an average of 1.47 Mg ha−1 a−1 in the soil and 0.20 Mg ha−1 a−1 in the forest floor. Organic carbon sequestered annually in the soil was significantly lower in thinned than in unthinned stands, while differences in the forest floor were insignificant. There were positive correlations between carbon sequestered in the soil and stand age, average DBH, mean stand height, basal area, and site index. Carbon sequestered the forest floor increased with basal area. As a result, carbon sequestered in the soil should not be ignored in greenhouse gas inventories because carbon stored belowground was approximately 70% of the aboveground pool.

Spatial distribution patterns of annual soil carbon accumulation and carbon storage in the Jiuduansha wetland of the Yangtze River estuary.

Wetlands are important carbon (C) pools for terrestrial ecosystems, and C stored in different types of wetlands accounts for about 30% of total terrestrial C. As one of the most important ecological barriers in Shanghai, with functions of climate regulation, interception, and purification, and as a C sink, the Jiuduansha wetland has received research attention. However, little research has been done on the spatial differences in amount of average annual net C accumulation and C storage of each shoal: Jiangya Nansha, Shangsha, and Zhongxiasha. In this study, plant biomass, plant organic C, soil respiration, soil organic C content, and soil bulk density of different vegetation zones in the three shoals were analyzed to determine the spatial variability of annual net C accumulation capability and soil organic C storage of the Jiuduansha wetland. The results showed that the Zhongxiasha shoal played the most important role as a C sink, and it accumulated 77,839.44 t organic C per year. Regarding the annual C accumulation capacity per unit area, the Phragmites communis zone was higher than for all other vegetation zones, indicating that P. communis had the greatest C accumulation capacity. 7835.38 t, 46,827.41 t, and 173,623.1 t of organic C were stored in the Jiangya Nansha, Shangsha, and Zhongxiasha shoals, respectively. The C storage in soil was closely related to annual C accumulation, and there were two main reasons for the difference of spatial pattern of annual C accumulation: biomass and properties of plants and the properties of tidal water.