Ideas and perspectives: Enhancing research and monitoring of carbon pools and land-to-atmosphere greenhouse gases exchange in developing countries

Biogeosciences, Год журнала: 2022, Номер 19(5), С. 1435 - 1450

Опубликована: Март 10, 2022

Abstract. Carbon (C) and greenhouse gas (GHG) research has traditionally required data collection analysis using advanced often expensive instruments, complex proprietary software, highly specialized technicians. Partly as a result, relatively little C GHG been conducted in resource-constrained developing countries. At the same time, these are countries regions which climate change impacts will likely be strongest major science uncertainties centered, given importance of dryland tropical systems to global cycle. Increasingly, scientific communities have adopted appropriate technology approach (AT&A) for research, focuses on low-cost low-technology open-source software data, participatory networking-based approaches. Adopting AT&A can mean acquiring with fewer technical constraints lower economic burden is thus strategy enhancing However, higher uncertainties; mitigated by carefully designing experiments, providing clear protocols collection, monitoring validating quality obtained data. For implementing this countries, it first necessary recognize moral AT&A. new techniques should identified further developed. All processes promoted collaboration local researchers through training staff encouraged wide use innovation

Язык: Английский

---

Spatial variability and uncertainty of soil nitrogen across the conterminous United States at different depths

Ecosphere, Год журнала: 2022, Номер 13(7)

Опубликована: Июль 1, 2022

Abstract Soil nitrogen (N) is an important driver of plant productivity and ecosystem functioning; consequently, it critical to understand its spatial variability from local‐to‐global scales. Here, we provide a quantitative assessment the three‐dimensional distribution soil N across United States (CONUS) using digital mapping approach. We used random forest‐regression kriging algorithm predict concentrations associated uncertainty six depths (0–5, 5–15, 15–30, 30–60, 60–100, 100–200 cm) at 5‐km grids. Across CONUS, there strong dependence N, where decrease but increases with depth. was higher in Pacific Northwest, Northeast, Great Lakes National Ecological Observatory Network (NEON) ecoclimatic domains. Model Atlantic Neotropical, Southern Rockies/Colorado Plateau, Southeast NEON also compared our predictions satellite‐derived gross primary production forest biomass Biomass Carbon Dataset. Finally, information propose optimized locations for designing future surveys found that Southwest, Appalachian/Cumberland Plateau domains may require larger survey efforts. highlight need increase knowledge biophysical factors regulating processes deeper better characterize space soils. Our results national benchmark regarding reveal areas representation.

Язык: Английский

---

WetCH₄: A Machine Learning-based Upscaling of Methane Fluxes of Northern Wetlands during 2016–2022

Опубликована: Апрель 3, 2024

Abstract. Wetlands are the largest natural source of methane (CH4) emissions globally. Northern wetlands (>45° N), accounting for 42 % global wetland area, increasingly vulnerable to carbon loss, especially as CH4 may accelerate under intensified high-latitude warming. However, magnitude and spatial patterns remain relatively uncertain. Here we present estimates daily fluxes obtained using a new machine learning-based upscaling framework (WetCH4) that applies most complete database eddy covariance (EC) observations available date, satellite remote sensing informed environmental conditions at 10-km resolution. The important predictor variables included near-surface soil temperatures (top 40 cm), vegetation reflectance, moisture. Our results, modeled from 138 site-years across 26 sites, had strong predictive skill with mean R2 0.46 0.62 absolute error (MAE) 23 nmol m-2 s-1 21 monthly fluxes, respectively. Based on model estimated an annual average 20.8 ±2.1 Tg yr-1 northern region (2016–2022) total budgets ranged 13.7–44.1 yr-1, depending map extents. Although 86 budget occurred during May–October period, considerable amount (1.4 ±0.2 CH4) winter. Regionally, West Siberian accounted majority (51 %) interannual variation in domain emissions. Significant issues data coverage remain, only sites observing year-round 11 Alaska 10 bog/fen Canada Fennoscandia, general, Western Lowlands underrepresented by EC sites. results provide high spatiotemporal information cycle possible responses climate change. Continued, all-season tower improved moisture products needed future improvement upscaling. dataset can be found https://doi.org/10.5281/zenodo.10802154 (Ying et al., 2024).

Язык: Английский

---

Surface Urban Energy and Water Balance Scheme (v2020a) in vegetated areas: parameter derivation and performance evaluation using FLUXNET2015 dataset

Geoscientific model development, Год журнала: 2022, Номер 15(7), С. 3041 - 3078

Опубликована: Апрель 8, 2022

Abstract. To compare the impact of surface–atmosphere exchanges from rural and urban areas, fully vegetated areas (e.g. deciduous trees, evergreen trees grass) commonly found adjacent to cities need be modelled. Here we provide a general workflow derive parameters for SUEWS (Surface Urban Energy Water Balance Scheme), including those associated with vegetation phenology (via leaf area index, LAI), heat storage surface conductance. As expected, attribution analysis bias in SUEWS-modelled QE finds that conductance (gs) plays dominant role; hence there is more estimates parameters. The applied at 38 FLUXNET sites. derived vary between sites same plant functional type (PFT), demonstrating challenge using single set PFT. skill simulating monthly hourly latent flux (QE) examined site-specific parameters, default NOAH (Chen et al., 1996). Overall evaluation 2 years has similar metrics both configurations: median hit rate 0.6 0.7, mean absolute error less than 25 W m−2, ∼ 5 m−2. Performance differences are evident scales, larger (monthly: 40 m−2; 30 m−2) results NOAH-surface suggesting they should used caution. Assessment contrasting performance demonstrates how critical capturing LAI dynamics prediction skills gs QE. Generally poorest cooler periods (more pronounced night, when underestimated by 3 mm s−1). Given global data availability provided this study, any site simulated benefit.

Язык: Английский

---

CO₂ flux in a wheat‐soybean succession in subtropical Brazil: A carbon sink

Journal of Environmental Quality, Год журнала: 2022, Номер 51(5), С. 899 - 915

Опубликована: Апрель 22, 2022

The subtropical region of Brazil is home to 33% the soybean [Glycine max (L.) Merr.] growing area and 90% wheat (Tritucum aestivum L.) this country. A soybean-wheat succession with fallow between crops used in about 11% cultivated area. No study has quantified CO2 fluxes annual region. Hence, analyzed seasonality exchange (net ecosystem [NEE]) a 2015/2016 wheat-soybean commercial farm located Carazinho, Rio Grande do Sul State, Brazil. eddy covariance method was estimate C balance system. NEE partitioned gross primary productivity respiration understand dynamics these during year succession. Considering net photosynthesis season, both absorbed from atmosphere (NEE wheat: -347 ± 4 g m-2 ; soybean: -242 3 ). periods seasons, however, acted as source 156 2 , reducing by 27%. For 1 yr, biome -50 yr-1 . results obtained here demonstrate that sink under specific climatic conditions field management practices long period limited agroecosystem becoming more efficient sink.

Язык: Английский

---