Carbon Balance and Management最新文献

Background

The Amazonian forests are increasingly threatened due to continuous changes in land use, particularly deforestation. This study aimed to quantify and analyze the vertical distribution of soil glomalin and its relationship with carbon, climate, and soil properties across three forest types of the Peruvian Amazon. A total of 18 plots were selected and sampled in forests with different vegetation cover types: deforested, disturbed, and primary forest. The vertical variation of total glomalin (TG), easily extractable glomalin (EEG), and the number of arbuscular mycorrhizal fungal (AMF) spores was estimated, as it was the relationships of these variables with soil depth, physical-chemical properties, and climate conditions.

Results

The mean values for TG, EEG, and AMF showed vertical variations in the three forest cover types, with high values in disturbed forests and degraded soils. Overall, higher mean values were found in the surface soil layers compared to the deep layers. TG, EEG, and AMF were positively corelated with soil organic carbon (SOC) and soil organic matter (SOM). Moreover, the total nitrogen (N), SOC, OM, total phosphorus (P), and soil water content (SWC) presented higher values in the topsoil than the deep layers.

Conclusions

The highest production of glomalin in disturbed forests is probably a response to degradation processes. This work is a contribution to expand knowledge about glomalin dynamics in forest soils of the Amazon rainforest and provides essential information for future soil ecosystem restoration practices in tropical forests.

Background

The Global Carbon Project provides annual updates on anthropogenic and natural components of the Global Carbon Budget. Dynamic Global Vegetation Models (DGVMs) contribute to these estimates and are used to simulate the evolution of terrestrial carbon sinks. However, DGVMs are known to poorly represent disturbances such as fire, leading to uncertainties in estimates of mean, interannual variability (IAV), and trends in land carbon fluxes. To address this issue, we propose a hybrid-process-based assessmentby constraining three DGVMs (OCN, JULES-INFERNO, and ORCHIDEE-MICT) with remotely-sensed burned areas from ESA CCI (FIRECCI51) and climate data from ERA5 reanalysis. We aim to improve the representation of the spatio-temporal variability of regional carbon budgets, namely fire emissions, above-ground biomass carbon (AGC), and vegetation-related variables—leaf area index (LAI) and gross primary productivity (GPP).

Results

Prescribing burned area (BA) in DGVMs reveals contrasting patterns between prognostic (model simulations) and diagnostic (simulations with prescribed BA) runs. As prognostic tends to overestimate BA, particularly across tropical and high-latitude regions, diagnostic simulations correct this issue, by reducing bias and improving the IAV and the agreement with satellite-based datasets of BA and fire emissions in these regions. Moreover, enhanced IAV of AGC is simulated by diagnostic runs, essentially due to better representation of biomass carbon in the mentioned regions. Although moderate improvements are found in LAI and GPP, as the differences between the two runs are more limited, the improvements between prognostic and diagnostic are more evident in their IAV, particularly for LAI, rather than on long-term means, indicating that prescribed fire can improve the representation of some variability patterns.

Conclusions

Prescribing remotely-sensed BA in models can lead to a better representation of global BA, fire emissions and AGC, particularly improving the IAV, reducing bias and enhancing the agreement with satellite datasets. The moderate improvements in vegetation-related variables underscore the need to better constrain fire impacts and vegetation dynamics in models, to enhance the simulation of spatio-temporal variability and dynamics of regional-scale vegetation and carbon-related fluxes.

The report of the 20th National Congress of the Communist Party of China clearly states that ecological environment protection is an inherent requirement for the comprehensive construction of a socialist modernized country, and points out the need to “adhere to the concept that green mountains and clear waters are as valuable as mountains of gold and silver, and deepen the fight against pollution prevention and control”. Manufacturing enterprises are the main body of energy conservation and carbon reduction, and also an important component of the entire green, low-carbon, and circular economy system. Accelerating the promotion of environmental governance in manufacturing enterprises is essential for achieving green development in the manufacturing industry. Practice has shown that the central environmental inspection takes “promoting development through inspection” as an important principle and basic starting point, fully exerting its coercive and guiding role, seriously dealing with major ecological damage and environmental pollution, promoting the accelerated development of green industries, and becoming a powerful lever for promoting environmental governance in manufacturing enterprises. This article explores the impact of central environmental inspections on environmental governance in manufacturing enterprises by using a multi period double difference model and starting from the internal dynamic mechanism of central environmental inspections driving manufacturing enterprises. This article finds that the central environmental inspection promotes environmental governance by influencing the attention allocation of enterprises, and the effect of the central environmental inspection varies depending on regional location, environmental law enforcement strength, and enterprise performance; In enterprises in the eastern region and areas with high environmental law enforcement, central environmental inspections have played a significant role in promoting environmental governance in manufacturing enterprises. However, in enterprises in the central and western regions and areas with low environmental law enforcement, the role of central environmental inspections is not significant. Compared with manufacturing enterprises with poor business performance, manufacturing enterprises with good business performance will perform better in environmental governance when facing central environmental inspections.

Background

Rising temperatures and altered precipitation patterns are expected to have profound impacts on the composition and condition of boreal forests. As a result there are growing needs for climate adaptation strategies in boreal forest management; one potential solution to achieve these goals is the utilization of nature-based climate-informed adaption solutions including afforestation using deciduous species which can help offset carbon emissions and sequester carbon at an increased rate. Deciduous afforestation has the potential to allow mangers to adapt fire-risk, while increasing carbon storage. Here, we investigated the impact of deciduous compared to coniferous afforestation on biomass accumulation in the Canadian boreal using a process-based model (3-PG). 3-PG utilises physiological principals to predict the growth of individual species across a variety of climate scenarios. This approach is valuable for projecting forest growth under changing climate, as it can account for plant responses to environmental factors which may not be captured by empirical models based on historical data. We simulated forest growth under three future climate scenarios to 2080, and compared the aboveground biomass (AGB, tons of Dry Matter per hectare; tDM ha⁻¹) accumulated to baseline estimates using locally adapted coniferous species. In addition, we investigated the modelled effects of converting from conifer to deciduous species on stand level soil water and vapor pressure deficit responses to climate.

Results

We found that deciduous simulations sequester more carbon under all climate scenarios, with the greatest difference occurring in the warmest scenario (171 tDM ha⁻¹ for coniferous species compared to 347.1 tDM ha⁻¹ for deciduous species). Coniferous species were generally more water stressed than deciduous species; conifers were generally 65.6% more stressed compared to deciduous species in August under the warmest climate scenario, while northern sites were less stressed than southern sites.

Conclusions

Simulations such as these highlight the importance of modelling and consideration of different planting scenarios in decision-making to ensure successful resource allocation. They also demonstrate the potential of nature-based adaptation solutions projects, and the role deciduous afforestation can play in provision of habitat, modifying wildfire risk and northern boreal biomass and timber supply.

Accurate estimation of forest carbon stocks is essential for climate change mitigation, particularly in peatland ecosystems known for their high soil organic carbon content. However, biomass equations currently used in Germany, such as the ^“regular” biomass equation of the National Forest Inventory integrated in the TapeS R package, are primarily calibrated for mineral soil sites and may misestimate biomass in peatland forests. This study evaluates the applicability of existing biomass equations for Alnus glutinosa and Betula pubescens in forested peatlands across Germany by comparing estimates of the biomass equation of the National Forest Inventory with a set of alternative allometric functions, including peatland-specific equations. Using data from 65 forests at peatland and 1266 forests at mineral soil sites, we assessed tree growth patterns, aboveground biomass, and carbon stocks. Results indicate significant differences in growth dynamics between peatland and mineral sites, with trees at peatland sites exhibiting lower heights and biomass at a given diameter. Despite this, stand level carbon estimates by the standard biomass equation of the National Forest Inventory aligned closely with the mean of all equations for both species and did not show a consistent bias, although it overestimated individual tree biomass for Betula pubescens. Notably, peatland-specific functions show high variability and no clear advantage over the biomass equation of the National Forest Inventory. We conclude that while the equation of the National Forest Inventory currently provides robust estimates for the carbon stock of peatland forests in Germany on stand level for Betula pubescens and Alnus glutinosa, future recalibration may be needed as restoration efforts and climate change alter site conditions. For local-scale applications, especially in intact or rewetted peatlands, site-adapted equations are recommended to account for the high spatial heterogeneity and complex growth dynamics of these ecosystems.