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The impact of urbanization and economic growth on terrestrial carbon storage is a complex and multidimensional issue involving land use change, carbon cycle, ecosystem services, etc. Remote sensing technology plays an important role in this study because it can provide a large amount of spatial and temporal data to help monitor and evaluate these impacts. In this study, we used Geo AI to optimize the predictive capabilities of the InVEST model, improve the efficiency and accuracy of data processing, and provide more accurate data support for the InVEST model. The study found that: (1) the overall carbon sequestration across the YREB decreased, with a reduction of 0.35%, 0.85%, and 2.28% in the upper, middle and lower reaches respectively. Notably, the upper region witnessed an expanding trend of carbon sequestration loss, while the lower region has shown some degree of alleviation. (2) The coupling degree between urbanization and carbon sequestration in Shanghai is significantly lower compared to other regions. Additionally, regions with an increasing coupling degree between carbon sequestration and population have a population urbanization rate generally below 60%. Similarly, regions with relatively lower land coupling degree have a land urbanization rate below 11%. Furthermore, regions with lower industrial coupling degree have an industrial urbanization rate exceeding 92%. (3) Carbon sequestration and economic growth exhibit a decoupling trend, with the lower region having a lower decoupling degree compared to the middle and upper regions. However, the decoupling status in the middle and upper regions tends to deteriorate, while the lower region shows signs of improvement. [ABSTRACT FROM AUTHOR]

ABSTRACTUrbanization improves the living environment of billions of people but negatively impacts the local carbon cycle as it encroaches on ecosystems. We analyzed this dual effect of urbanization by quantifying linkages between several indicators — urbanization-induced terrestrial carbon storage loss (uTCSL), per capita urban area (PCUA), and urban land use efficiency (LCRPGR) — within the Hohhot-Baotou-Ordos (HBO) region in 1990–2100. Results show that the growth of 4.45 million urban residents and 420.70 km2 urban area led to a uTCSL of 815.74 GgC in the HBO region in 1990–2020. The uTCSL contributed to improving the urban crowding indicated by PCUA but was subject to LCRPGR. The PCUA decreased by −33.75 m2/person under high land use efficiency (LCRPGR

The establishment of the ecological protection redline (EPR) in China plays a crucial role in safeguarding key ecological functional areas and sustaining biodiversity. Besides their significance, the impact of these redlines on regional carbon sequestration remains unclear due to current inconsistencies in their implementation and adjustment. This paper conducts a thorough analysis of the evolution of two EPR versions on Hainan Island and employs the InVEST model to assess the effects of two EPR areas on regional carbon storage between 2000 and 2020. Additionally, a spatial autoregressive model is integrated to explore the socioeconomic and environmental driving mechanisms behind changes in regional carbon storage, thereby revealing complex interactions between ecological protection policy adjustments and ecosystem services of carbon storage. Key findings include: (1) The 2022 EPR area has improved the management of ecological protection boundaries, permanent cultivated land, and urban development boundaries, outperforming the 2016 version, particularly in control of construction land and water resource management. (2) The EPR2022 exhibits higher carbon storage per area, indicating a more effective zoning system. The increase in carbon storage is primarily observed in transitions from cultivated land to forest, grassland to forest, and water bodies to grassland. (3) Elevation exhibits a relatively strong positive correlation with carbon storage within the EPRs, with high-altitude areas typically encompassing the core zones of tropical rainforest national parks that possess diverse vegetation and stable ecosystems, conducive to maintaining or increasing carbon storage. Evaluating the efficacy of the EPR in enhancing regional carbon storage is critical for refining management strategies and achieving carbon neutrality goals. Future strategies should incorporate a comprehensive analysis of ecosystem services of carbon storage into the EPR framework to enhance multiple ecosystem functions, thereby establishing a resilient and functionally stable ecological landscape. This research introduces an insightful estimation method crucial for developing more effective ecological protection policies and provides valuable insights for managing ecological protection areas globally. [ABSTRACT FROM AUTHOR]

The establishment of the ecological protection redline (EPR) in China plays a crucial role in safeguarding key ecological functional areas and sustaining biodiversity. Besides their significance, the impact of these redlines on regional carbon sequestration remains unclear due to current inconsistencies in their implementation and adjustment. This paper conducts a thorough analysis of the evolution of two EPR versions on Hainan Island and employs the InVEST model to assess the effects of two EPR areas on regional carbon storage between 2000 and 2020. Additionally, a spatial autoregressive model is integrated to explore the socioeconomic and environmental driving mechanisms behind changes in regional carbon storage, thereby revealing complex interactions between ecological protection policy adjustments and ecosystem services of carbon storage. Key findings include: (1) The 2022 EPR area has improved the management of ecological protection boundaries, permanent cultivated land, and urban development boundaries, outperforming the 2016 version, particularly in control of construction land and water resource management. (2) The EPR2022 exhibits higher carbon storage per area, indicating a more effective zoning system. The increase in carbon storage is primarily observed in transitions from cultivated land to forest, grassland to forest, and water bodies to grassland. (3) Elevation exhibits a relatively strong positive correlation with carbon storage within the EPRs, with high-altitude areas typically encompassing the core zones of tropical rainforest national parks that possess diverse vegetation and stable ecosystems, conducive to maintaining or increasing carbon storage. Evaluating the efficacy of the EPR in enhancing regional carbon storage is critical for refining management strategies and achieving carbon neutrality goals. Future strategies should incorporate a comprehensive analysis of ecosystem services of carbon storage into the EPR framework to enhance multiple ecosystem functions, thereby establishing a resilient and functionally stable ecological landscape. This research introduces an insightful estimation method crucial for developing more effective ecological protection policies and provides valuable insights for managing ecological protection areas globally.

Over the past four decades, global land greening has promoted carbon (C) storage in terrestrial ecosystems. However, whether the future trajectory of this positive greening effect on ecosystem C sequestration is sustainable under various climate scenarios remains uncertain. Here, using projections from ten Earth system models, we found divergent trends in the relationship between global land greening and C storage among three distinct shared socioeconomic pathways (SSPs). We identified global transition times for their positive relationships, which will occur in 2034, 2038, and 2048 for SSP1-2.6, SSP2-4.5, and SSP5-8.5, respectively. We found a widespread decoupling trend of vegetation greening and ecosystem C storage under medium to high emission scenarios, particularly in the tundra, boreal forest, and grassland regions, by delving deeper into six transition modes. These findings underscore the highly uncertain role of vegetation greening in land C sequestration under prospective climate change scenarios.

Assessing the impacts and drivers of urban expansion on terrestrial carbon storage (TCS) is important for urban ecology and sustainability; however, a unified accounting standard for carbon intensity and research on the drivers and economic value of TCS changes are lacking. Here, urban expansion and TCS in the Yangtze River Delta were simulated based on Patch-generating Land Use Simulation and Integrated Valuation of Ecosystem Services and Trade-offs models; scenario simulation; Literature, Correction, Ratio, Verification carbon intensity measurement; and land use transfer matrix methods. The results showed that (1) from 2000 to 2020, urbanization and TCS loss accelerated, with 61.127% of TCS loss occurring in soil, and land conversion was prominent in riverine and coastal cities, mainly driven by the urban land occupation of cropland around suitable slopes, transportation arteries, and rivers. (2) From 2020 to 2030, urban land expansion and TCS loss varied under different scenarios; economic losses from the loss of the carbon sink value under cropland protection and ecological protection were USD 102.368 and 287.266 million lower, respectively, than under the baseline scenario. Even if urban expansion slows, the loss of TCS under global warming cannot be ignored. Considering the indirect impacts of urbanization, the failure to establish a regional development master plan based on ecosystem services may affect China's carbon targets. [ABSTRACT FROM AUTHOR]

The degree to which elevated CO2 concentrations (e[CO2]) increase the amount of carbon (C) assimilated by vegetation plays a key role in climate change. However, due to the short‐term nature of CO2 enrichment experiments and the lack of reconciliation between different ecological scales, the effect of e[CO2] on plant biomass stocks remains a major uncertainty in future climate projections. Here, we review the effect of e[CO2] on plant biomass across multiple levels of ecological organization, scaling from physiological responses to changes in population‐, community‐, ecosystem‐, and global‐scale dynamics. We find that evidence for a sustained biomass response to e[CO2] varies across ecological scales, leading to diverging conclusions about the responses of individuals, populations, communities, and ecosystems. While the distinct focus of every scale reveals new mechanisms driving biomass accumulation under e[CO2], none of them provides a full picture of all relevant processes. For example, while physiological evidence suggests a possible long‐term basis for increased biomass accumulation under e[CO2] through sustained photosynthetic stimulation, population‐scale evidence indicates that a possible e[CO2]‐induced increase in mortality rates might potentially outweigh the effect of increases in plant growth rates on biomass levels. Evidence at the global scale may indicate that e[CO2] has contributed to increased biomass cover over recent decades, but due to the difficulty to disentangle the effect of e[CO2] from a variety of climatic and land‐use‐related drivers of plant biomass stocks, it remains unclear whether nutrient limitations or other ecological mechanisms operating at finer scales will dampen the e[CO2] effect over time. By exploring these discrepancies, we identify key research gaps in our understanding of the effect of e[CO2] on plant biomass and highlight the need to integrate knowledge across scales of ecological organization so that large‐scale modeling can represent the finer‐scale mechanisms needed to constrain our understanding of future terrestrial C storage. [ABSTRACT FROM AUTHOR]

The degree to which elevated CO2 concentrations (e[CO2]) increase the amount of carbon (C) assimilated by vegetation plays a key role in climate change. However, due to the short‐term nature of CO2 enrichment experiments and the lack of reconciliation between different ecological scales, the effect of e[CO2] on plant biomass stocks remains a major uncertainty in future climate projections. Here, we review the effect of e[CO2] on plant biomass across multiple levels of ecological organization, scaling from physiological responses to changes in population‐, community‐, ecosystem‐, and global‐scale dynamics. We find that evidence for a sustained biomass response to e[CO2] varies across ecological scales, leading to diverging conclusions about the responses of individuals, populations, communities, and ecosystems. While the distinct focus of every scale reveals new mechanisms driving biomass accumulation under e[CO2], none of them provides a full picture of all relevant processes. For example, while physiological evidence suggests a possible long‐term basis for increased biomass accumulation under e[CO2] through sustained photosynthetic stimulation, population‐scale evidence indicates that a possible e[CO2]‐induced increase in mortality rates might potentially outweigh the effect of increases in plant growth rates on biomass levels. Evidence at the global scale may indicate that e[CO2] has contributed to increased biomass cover over recent decades, but due to the difficulty to disentangle the effect of e[CO2] from a variety of climatic and land‐use‐related drivers of plant biomass stocks, it remains unclear whether nutrient limitations or other ecological mechanisms operating at finer scales will dampen the e[CO2] effect over time. By exploring these discrepancies, we identify key research gaps in our understanding of the effect of e[CO2] on plant biomass and highlight the need to integrate knowledge across scales of ecological organization so that large‐scale modeling can represent the finer‐scale mechanisms needed to constrain our understanding of future terrestrial C storage. [ABSTRACT FROM AUTHOR]

Carbon storage in terrestrial ecosystems, which is the basis of the global carbon cycle, reflects the changes in the environment due to anthropogenic impacts. Rapid and effective assessment of the impact of urban expansion on carbon reserves is vital for the sustainable development of urban ecosystems. Previous studies on future scenario simulations lacked research regarding the driving factors of changes in carbon storages within urban expansion, and the economic value accounting for changes in carbon storages. Therefore, this study examined Wuhan, China, and explored the latent effects of urban expansion on terrestrial carbon storage by combining the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and Patch-generating Land Use Simulation (PLUS) model. Based on different socioeconomic strategies, we developed three future scenarios, including Baseline Scenario (BS), Cropland Protection Scenario (CP) and Ecological protection Scenario (EP), to predict the urban built-up land use change from 2015 to 2035 in Wuhan and discussed the carbon storage impacts of urban expansion. The result shows that (1) Wuhan's urban built-up land area expanded 2.67 times between 1980 and 2015, which is approximately 685.17 km2 and is expected to continuously expand to 1349–1945.01 km2 by 2035. (2) Urban expansion in Wuhan has caused carbon storage loss by 5.12 × 106 t during 1980–2015 and will lead to carbon storage loss by 6.15 × 106 t, 4.7 × 106 t and 4.05 × 106 t under BS, CP, and EP scenarios from 2015 to 2035, accounting for 85.42%, 81.74%, and 78.79% of the total carbon loss, respectively. (3) The occupation of cropland by urban expansion is closely related to the road system expansion, which is the main driver of carbon storage reduction from 2015 to 2035. (4) We expect that by 2035, the districts facing carbon loss caused by the growth of urban built-up land will expand outward around secondary roads, and the scale of outward expansion under various scenarios will be ranked as BS > CP > EP. In combination, the InVEST and the PLUS model can assess the impact of urban expansion on carbon storage more efficiently and is conducive to carrying out urban planning and promoting a dynamic balance between urban economic development and human well-being. [ABSTRACT FROM AUTHOR]

Many institutions have substantial landholdings, but few consider soil carbon preservation and augmentation in their carbon management plans. A methodical framework was developed to analyse terrestrial carbon stocks (soil and tree biomass) for credible carbon offsetting strategies in institutional land. This approach was demonstrated at two farms (805 hectares) managed by Newcastle University. Soil carbon for three depths (0–30 cm, 30–60 cm and 60–90 cm) and above‐ground tree biomass were quantified. These data provided a terrestrial carbon baseline to evaluate future land management options and effects. Historical land‐use records enabled the following comparisons: (1) agricultural land vs. woodland; (2) arable land vs. permanent grassland; (3) organic vs. conventional farming; (4) coniferous vs. broadleaved woodland; and (5) recent vs. long‐established woodland. Carbon storage (kg/m2) varied with land usage and woodland type and age, but only agricultural land vs. woodland, and for agriculture, arable land vs. permanent grassland, significantly affected the 0–90 cm soil carbon. At the university‐managed farms, current terrestrial carbon stocks were 103,620 tonnes in total (98,050 tonnes from the 0–90 cm soil and 5,569 tonnes from tree biomass). These terrestrial carbon stocks were equivalent to sixteen years of the current carbon emissions of Newcastle University (6,406 tonnes CO2 equivalents‐C per year). Using strategies for alternative land management, Newcastle University could over 40 years offset up to 3,221 tonnes of carbon per year, or 50% of its carbon emissions at the current rate. The methodological framework developed in this study will enable institutions having large landholdings to rationally consider their estates in future soil carbon management schemes. [ABSTRACT FROM AUTHOR]

Here we examine the causal effects of El Niño–Southern Oscillation (ENSO) on the global carbon cycle over historical and future periods utilizing datasets from the Coupled Modeling Intercomparison Project Phase 6 models. Our results show that ENSO exhibits impact on terrestrial carbon fluxes and carbon storage over numerous regions of Asia, Oceania, and America. High consensus is found between models for the influences of ENSO over these regions. The results demonstrate that the effects of ENSO on carbon cycling over subtropics and high‐latitude regions may be more significant than previously understood. In historical simulation, the regions affected by ENSO account for approximately 8.5% land‐area and this proportion rises to approximately 11.7% in the future simulation, indicating an increase in ENSO influences on the gross primary productivity of terrestrial ecosystems. In addition, the results emphasize stronger response of seasonal carbon stocks to ENSO compared to that of seasonal carbon fluxes. Plain Language Summary: The global carbon cycle is an essential component of the Earth climate system. However, there is uncertainty in the response of future carbon cycling to El Niño–Southern Oscillation (ENSO) variations. Under warming environment and anthropogenic impacts, further understanding of ENSO and carbon cycle connections is important to accurately estimate future climate change and extremes. In the present study, we examine the causal effects of ENSO on the global carbon cycle over the future period 2015–2100 utilizing datasets from climate model simulations. Our results show that ENSO exhibits impact on carbon cycling over numerous regions of Asia, Oceania, and America. The results underscore that the impacts of ENSO on carbon cycling over subtropical and high‐latitude regions may be more significant than previously understood. We conclude that the future projections show an increase in ENSO influences on terrestrial carbon cycle compared to the historical period 1915–2000. In historical simulation, the regions with significant ENSO effects on gross primary productivity account for 8.5% land‐area and this proportion rises to 11.7% in the future simulation. This work might contribute to the forthcoming adaptation of global change and carbon neutrality policy. Key Points: El Niño–Southern Oscillation (ENSO) exhibits causal impact on carbon fluxes and terrestrial carbon storage over numerous regions of Asia, Oceania, and AmericaProjections over the future period show an increase in land‐area of regions affected by ENSO compared to the historical periodThe results emphasize that the response of seasonal carbon stocks to ENSO is stronger compared to the response of seasonal carbon fluxes [ABSTRACT FROM AUTHOR]

Assessing the impacts and drivers of urban expansion on terrestrial carbon storage (TCS) is important for urban ecology and sustainability; however, a unified accounting standard for carbon intensity and research on the drivers and economic value of TCS changes are lacking. Here, urban expansion and TCS in the Yangtze River Delta were simulated based on Patch-generating Land Use Simulation and Integrated Valuation of Ecosystem Services and Trade-offs models; scenario simulation; Literature, Correction, Ratio, Verification carbon intensity measurement; and land use transfer matrix methods. The results showed that (1) from 2000 to 2020, urbanization and TCS loss accelerated, with 61.127% of TCS loss occurring in soil, and land conversion was prominent in riverine and coastal cities, mainly driven by the urban land occupation of cropland around suitable slopes, transportation arteries, and rivers. (2) From 2020 to 2030, urban land expansion and TCS loss varied under different scenarios; economic losses from the loss of the carbon sink value under cropland protection and ecological protection were USD 102.368 and 287.266 million lower, respectively, than under the baseline scenario. Even if urban expansion slows, the loss of TCS under global warming cannot be ignored. Considering the indirect impacts of urbanization, the failure to establish a regional development master plan based on ecosystem services may affect China’s carbon targets.

Understanding the impacts of large-scale anthropogenic drivers on spatiotemporal processes in carbon storage through land-use patterns is a growing issue for the assessment of terrestrial ecosystems. However, an integrated assessment of changes in carbon storage, entailing complex land-use and land-cover (LULC) dynamics, remains a challenge. This study assessed the consequences of LULC changes on regional carbon storage in the Loess Plateau from 1995 to 2050 by integrating spatially explicit LULC and carbon models using multi-source data and typical scenarios. A Markov-CA model was used to model past LULC dynamics, which was followed by future projections under different LULC scenarios. Each scenario represented different socio-economic trajectories, including historical trend, ecological priority, and urban priority. The integrated valuation of the ecosystem service and tradeoffs (InVEST) carbon storage model and statistical methods were then used to assess spatiotemporal changes in the regional carbon storage associated with LULC dynamics. The results indicated that the ecological priority scenario could increase carbon storage by 11.36 Pg between 2015 and 2050. This is due to an increase in the carbon storage capacity in grasslands, shrub forest, and evergreen coniferous forest, indicating that ecological restoration could increase carbon sequestration. This mitigates the carbon loss caused by the rapid expansion of built-up land and fluctuations in cropland, which often takes place in the urban priority and historical trend scenarios. In favor of targeting the northwestern and central regions with socioeconomic benefits, grasslands and forests should be further promoted in the Loess Plateau. The findings will help implement long-term carbon sequestration strategies for ecosystem conservation.

Landscapes have a structure that contains many functions and ecosystem services with their natural and cultural components. Vegetation especially in natural landscapes stands out not only visually, but also in terms of ecosystem services. It is known that carbon dioxide and carbon monoxide gases are among the greenhouse gases that have the highest share in global warming. Forest areas have climate protection functions by protecting settlements, agricultural areas and recreational facilities from the harmful effects of cold weather and wind, extreme weather changes and improving the regional climate. In this study, the focus is on the carbon storage service, which is evaluated in the category of regulatory services under ecosystem services. For the determination of forest biomass carbon storage capacity of Gokcay Basin, located in Turkey's western Black Sea region, biomass estimation method calculated at the unit area level is used within the scope of LULUCF (Land use land use change and forestry) applications. In the method: (i) map of forest stand types; (ii) acreage of forest stand types; (iii) tree volume value; (iv) biomass expansion factor, wood density, root/shoot rate coefficients, and (v) percent tree cover map produced with remote sensing data are used. [ABSTRACT FROM AUTHOR]

Terrestrial carbon storage is one of many different ways to tackle the problem of greenhouse gases (GHG) emissions resulting from non-point sources. However, the development of large-scale urban forest acreage is not an easy undertaking, and will require significant resources. The systematic screening of candidate tree species and preliminary estimations of their atmospheric carbon removal potential can help stakeholders and policymakers devise site-specific strategies for developing and maintaining sustainable urban forest acreage. This study is focused on finding native candidate trees that are drought-resistant, and could continue to store (sequester) atmospheric carbon in significant quantities over an extended period (> 100 years). In the study, seven urban tree species were identified as the top candidates for terrestrial carbon storage in water-stressed Californian regions, which are also the regions with the worst air quality in the nation. Although the present study is focused on particular water-stressed and air-polluted regions of California, the methodology and strategies presented may serve as a starting point for launching site-specific scoping studies to evaluate the terrestrial carbon storage potential of future urban forest projects in other parts of the world.

Highlights • I proposed a detachable carbon cycle model which contains 14 carbon pools to simulate carbon cycle and driven carbon pools to equilibrium state, each carbon pool or carbon flow process can detach from the main model as independent component for study. • Each carbon pool size and the internal carbon exchange was highly assessed by using detachable carbon cycle model, slow pool released the most CO 2 among all carbon pools. • The carbon influx-efflux (IE) function of each carbon pool can serve as a logistic function. Abstract Terrestrial carbon storage plays a crucial role in determining the global carbon cycle and regulating global climate. However, the carbon storage, as simulated by terrestrial biosphere models (TBMs), exhibits considerable inconsistency at the regional or global scale because the model structure, input dataset, and key parameter are quite different in TBMs. In this study, I proposed a detachable carbon cycle (DCC) model to simulate terrestrial carbon storage, internal carbon exchange, and the influx–efflux (IE) function of each carbon pool. The model was established based on a pool–and–flux scheme and contained 14 carbon pools, or carbon flow processes. Each process can be detached from the primary model and evaluated as an independent component. The average net primary productivity (NPP) from 1982 to 2008 was used as the influx carbon to drive the DCC model. The magnitude of the internal carbon exchanges of the DCC model was explicitly represented, and the carbon IE function of each carbon pool was fitted based on the characteristics of carbon flux. Results indicated that the terrestrial carbon storage was 2766.25 Pg, and carbon stored in vegetation and soil was 705.85 and 2022.00 Pg, respectively. Carbon stored in slow and passive pools accounted for 70.42% of the terrestrial carbon storage, and the slow pool contributes the highest amount of released CO 2 among of all carbon pools during carbon decomposition. The IE functions exhibited a nonlinear curve feature and satisfactory adjust-R2. This study aimed to contribute to our understanding of the carbon cycle from non-equilibrium state to equilibrium state and can serve as a reference and framework for global carbon storage simulation research. [ABSTRACT FROM AUTHOR]

Terrestrial carbon storage is one of many different ways to tackle the problem of greenhouse gases (GHG) emissions resulting from non-point sources. However, the development of large-scale urban forest acreage is not an easy undertaking, and will require significant resources. The systematic screening of candidate tree species and preliminary estimations of their atmospheric carbon removal potential can help stakeholders and policymakers devise site-specific strategies for developing and maintaining sustainable urban forest acreage. This study is focused on finding native candidate trees that are drought-resistant, and could continue to store (sequester) atmospheric carbon in significant quantities over an extended period (> 100 years). In the study, seven urban tree species were identified as the top candidates for terrestrial carbon storage in water-stressed Californian regions, which are also the regions with the worst air quality in the nation. Although the present study is focused on particular water-stressed and air-polluted regions of California, the methodology and strategies presented may serve as a starting point for launching site-specific scoping studies to evaluate the terrestrial carbon storage potential of future urban forest projects in other parts of the world. [ABSTRACT FROM AUTHOR]

This paper assesses the impacts of disturbance associated with the construction of a wind farm on fluxes of dissolved organic carbon (DOC) and suspended sediment from a blanket peat catchment in central Scotland during the period immediately following completion of construction. Six streams draining the site were sampled on six dates from October 2006, when construction was completed, and an additional three control streams to the west of the site were sampled on the same dates. Turbidity and stage were recorded semi-continuously in the two largest streams (one disturbed and one control), which were also sampled during storm events. Absorbance (400 nm) and DOC concentrations were determined on all samples, and suspended sediment was determined on the event samples. Absorbance and DOC were closely correlated in both the disturbed and undisturbed streams, with slightly greater absorbance per unit DOC in the disturbed streams. DOC concentrations in disturbed tributaries were always greater than those in undisturbed streams, with mean differences ranging from 2 to around 5 mg L-1. DOC and stage were positively correlated during events with maximum concentrations in excess of 30 mg L 1 at peak flow. Suspended sediment concentrations were markedly elevated in the disturbed stream with maximum concentrations at peak flow some 4–5 times greater than in the control. The colour of the sediment suggested that it was highly organic in nature at peak flow, and suspended particulate organic carbon represented a further loss of C from the site. Using flow-weighted mean DOC concentrations calculated for the storms monitored in autumn 2007, dissolved carbon losses can be estimated for the catchments of the disturbed and control streams. From these data the additional DOC loss related to disturbance associated with the wind farm is estimated at 5 g m-2.

Triose phosphate utilization (TPU)-limited photosynthesis occurs when carbon export from the Calvin-Benson cycle cannot keep pace with carbon inputs and processing. This condition is poorly constrained by observations but may become an increasingly important driver of global carbon cycling under future climate scenarios. However, the consequences of including or omitting TPU limitation in models have seldom been quantified. Here, we assess the impact of changing the representation of TPU limitation on leaf- and global-scale processes. At the leaf scale, TPU limits photosynthesis at cold temperatures, high CO _2 concentrations, and high light levels. Consistent with leaf-scale results, global simulations using the Community Land Model version 4.5 illustrate that the standard representation of TPU limits carbon gain under present day and future conditions, most consistently at high latitudes. If the assumed TPU limitation is doubled, further restricting photosynthesis, terrestrial ecosystem carbon pools are reduced by 9 Pg by 2100 under a business-as-usual scenario. The impact of TPU limitation on global terrestrial carbon gain suggests that CO _2 concentrations may increase more than expected if models omit TPU limitation, and highlights the need to better understand when TPU limitation is important, including variation among different plant types and acclimation to temperature and CO _2 .

The knowledge of potential impacts of climate change on terrestrial vegetation is crucial to understand long-term global carbon cycle development. Discrepancy in data has long existed between past carbon storage reconstructions since the Last Glacial Maximum by way of pollen, carbon isotopes, and general circulation model (GCM) analysis. This may be due to the fact that these methods do not synthetically take into account significant differences in climate distribution between modern and past conditions, as well as the effects of atmospheric CO2 concentrations on vegetation. In this study, a new method to estimate past biospheric carbon stocks is reported, utilizing a new integrated ecosystem model (PCM) built on a physiological process vegetation model (BIOME4) coupled with a process-based biospheric carbon model (DEMETER). The PCM was constrained to fit pollen data to obtain realistic estimates. It was estimated that the probability distribution of climatic parameters, as simulated by BIOME4 in an inverse process, was compatible with pollen data while DEMETER successfully simulated carbon storage values with corresponding outputs of BIOME4. The carbon model was validated with present-day observations of vegetation biomes and soil carbon, and the inversion scheme was tested against 1491 surface pollen spectra sample sites procured in Africa and Eurasia. Results show that this method can successfully simulate biomes and related climates at most selected pollen sites, providing a coefficient of determination ( R) of 0.83–0.97 between the observed and reconstructed climates, while also showing a consensus with an R-value of 0.90–0.96 between the simulated biome average terrestrial carbon variables and the available observations. The results demonstrate the reliability and feasibility of the climate reconstruction method and its potential efficiency in reconstructing past terrestrial carbon storage. [ABSTRACT FROM AUTHOR]

The interest in the national levels of the terrestrial carbon sink and its spatial and temporal variability with the climate and CO2 concentrations has been increasing. How the climate and the increasing atmospheric CO2 concentrations in the last century affect the carbon storage in continental China was investigated in this study by using the Modified Sheffield Dynamic Global Vegetation Model (M-SDGVM). The estimates of the M-SDGVM indicated that during the past 100 years a combination of increasing CO2 with historical temperature and precipitation variability in continental China have caused the total vegetation carbon storage to increase by 2.04 Pg C, with 2.07 Pg C gained in the vegetation biomass but 0.03 Pg C lost from the organic soil carbon matter. The increasing CO2 concentration in the 20th century is primarily responsible for the increase of the total potential vegetation carbon. These factorial experiments show that temperature variability alone decreases the total carbon storage by 1.36 Pg C and precipitation variability alone causes a loss of 1.99 Pg C. The effect of the increasing CO2 concentration alone increased the total carbon storage in the potential vegetation of China by 3.22 Pg C over the past 100 years. With the changing of the climate, the CO2 fertilization on China’s ecosystems is the result of the enhanced net biome production (NBP), which is caused by a greater stimulation of the gross primary production (GPP) than the total soil-vegetation respiration. Our study also shows notable interannual and decadal variations in the net carbon exchange between the atmosphere and terrestrial ecosystems in China due to the historical climate variability. [ABSTRACT FROM AUTHOR]

This paper assesses the impacts of disturbance associated with the construction of a wind farm on fluxes of dissolved organic carbon (DOC) and suspended sediment from a blanket peat catchment in central Scotland during the period immediately following completion of construction. Six streams draining the site were sampled on six dates from October 2006, when construction was completed, and an additional three control streams to the west of the site were sampled on the same dates. Turbidity and stage were recorded semicontinuously in the two largest streams (one disturbed and one control), which were also sampled during storm events. Absorbance (400 nm) and DOC concentrations were determined on all samples, and suspended sediment was determined on the event samples. Absorbance and DOC were closely correlated in both the disturbed and undisturbed streams, with slightly greater absorbance per unit DOC in the disturbed streams. DOC concentrations in disturbed tributaries were always greater than those in undisturbed streams, with mean differences ranging from 2 to around 5 mg L-1. DOC and stage were positively correlated during events with maximum concentrations in excess of 30 mg L-1 at peak flow. Suspended sediment concentrations were markedly elevated in the disturbed stream with maximum concentrations at peak flow some 4-5 times greater than in the control. The colour of the sediment suggested that it was highly organic in nature at peak flow, and suspended particulate organic carbon represented a further loss of C from the site. Using flow-weighted mean DOC concentrations calculated for the storms monitored in autumn 2007, dissolved carbon losses can be estimated for the catchments of the disturbed and control streams. From these data the additional DOC loss related to disturbance associated with the wind farm is estimated at 5 g m-2. [ABSTRACT FROM AUTHOR]

The equilibrium carbon storage capacity of the terrestrial biosphere has been investigated by running the Lund–Potsdam–Jena Dynamic Global Vegetation Model to equilibrium for a range of CO2 concentrations and idealized climate states. Local climate is defined by the combination of an observation-based climatology and perturbation patterns derived from a 4 × CO2 warming simulations, which are linearly scaled to global mean temperature deviations, Δ Tglob. Global carbon storage remains close to its optimum for Δ Tglob in the range of ±3°C in simulations with constant atmospheric CO2. The magnitude of the carbon loss to the atmosphere per unit change in global average surface temperature shows a pronounced nonlinear threshold behavior. About twice as much carbon is lost per degree warming for Δ Tglob above 3°C than for present climate. Tropical, temperate, and boreal trees spread poleward with global warming. Vegetation dynamics govern the distribution of soil carbon storage and turnover in the climate space. For cold climate conditions, the global average decomposition rate of litter and soil decreases with warming, despite local increases in turnover rates. This result is not compatible with the assumption, commonly made in global box models, that soil turnover increases exponentially with global average surface temperature, over a wide temperature range. [ABSTRACT FROM AUTHOR]

The equilibrium carbon storage capacity of the terrestrial biosphere has been investigated by running the Lund–Potsdam–Jena Dynamic Global Vegetation Model to equilibrium for a range of CO2 concentrations and idealized climate states. Local climate is defined by the combination of an observation-based climatology and perturbation patterns derived from a 4 × CO2 warming simulations, which are linearly scaled to global mean temperature deviations, Δ Tglob. Global carbon storage remains close to its optimum for Δ Tglob in the range of ±3°C in simulations with constant atmospheric CO2. The magnitude of the carbon loss to the atmosphere per unit change in global average surface temperature shows a pronounced nonlinear threshold behavior. About twice as much carbon is lost per degree warming for Δ Tglob above 3°C than for present climate. Tropical, temperate, and boreal trees spread poleward with global warming. Vegetation dynamics govern the distribution of soil carbon storage and turnover in the climate space. For cold climate conditions, the global average decomposition rate of litter and soil decreases with warming, despite local increases in turnover rates. This result is not compatible with the assumption, commonly made in global box models, that soil turnover increases exponentially with global average surface temperature, over a wide temperature range. [ABSTRACT FROM AUTHOR]