Understanding the sensitivity of ecosystem respiration (ER) to increasing temperature is crucial to predict how the terrestrial carbon sink responds to a warming climate. The temperature sensitivity of ER may vary on a diurnal basis but is poorly understood due to the paucity of observational sites documenting real ER during daytime at a global scale. Here, we used an improved flux partitioning approach to estimate the apparent temperature sensitivity of ER during the daytime (E) and nighttime (E) derived from multiyear observations of 189 FLUXNET sites.
View Article and Find Full Text PDFThe water-absorbent sensing film, coated on the surface of traditional optical fiber humidity sensors, often suffers from detachment issues. In this paper, we present what we believe to be a new fiber-optic cascaded Fabry-Perot interferometer sensor for detecting relative humidity (RH) and temperature, without the need for sophisticated instrumentation. The sensing structure comprises two sections of single-mode optical fibers and a C-shaped cavity between them.
View Article and Find Full Text PDFIn this work, a nested hollow-core anti-resonant fiber (HC-ARF) with an elliptical cladding for high-power lasers for 2 µm laser transmission was proposed and theoretically investigated. The dual-layer elliptical tubes nested within the fiber enable the low-loss single-mode transmission. The finite element method (FEM) was employed to analyze and optimize the structure of fiber, with a total loss of less than 5 × 10dB/m across the wavelength range of 1920nm to 2040nm.
View Article and Find Full Text PDFTo date, the understanding of the risks and impacts of microplastics (MPs) on terrestrial ecosystems remains limited, primarily due to most studies focusing on single ecosystem service. This study addressed this gap by conducting an integrative meta-analysis of 128 studies to explore the multifaceted impacts of MPs on various ecosystem services, including plant productivity, soil carbon (C) sequestration, microbial biodiversity, soil fertility, microbial biomass, and enzyme activity. We found that MPs reduced plant productivity service by 14.
View Article and Find Full Text PDFRiparian ecosystems are essential carbon dioxide (CO) sources, which considerably promotes climate warming. However, the other greenhouse gas fluxes (GHGs), such as methane (CH) and nitrous oxide (NO), in the riparian ecosystems have not been well studied, and it remains unclear whether and how these GHG fluxes respond to extreme weather, fertilization and hydrological alterations associated with reservoir management. Here, we assessed the impacts of hydrological alterations (i.
View Article and Find Full Text PDFSoil microbial diversity is crucial for regulating biogeochemical cycles, including soil carbon (C) dynamics and nutrient cycling. However, how climate, plants, and soil properties influence the microbiome in forests remains unclear, especially at the continental scale, hindering us to better understand forest C-climate change feedback. Here, we investigated the spatial patterns of microbial diversity across China's forests and explored the controlling factors of microbial β diversity and network complexity.
View Article and Find Full Text PDFEcological succession and restoration rapidly promote multiple dimensions of ecosystem functions and mitigate global climate change. However, the factors governing the limited capacity to sequester soil organic carbon (SOC) in old forests are poorly understood. Ecological theory predicts that plants and microorganisms jointly evolve into a more mutualistic relationship to accelerate detritus decomposition and nutrient regeneration in old than young forests, likely explaining the changes in C sinks across forest succession or rewilding.
View Article and Find Full Text PDFFungi are key decomposers of deadwood, but the impact of anthropogenic changes in nutrients and temperature on fungal community and its consequences for wood microbial respiration are not well understood. Here, we examined how nitrogen and phosphorus additions (field experiment) and warming (laboratory experiment) together influence fungal composition and microbial respiration from decomposing wood of angiosperms and gymnosperms in a subtropical forest. Nutrient additions significantly increased wood microbial respiration via fungal composition, but effects varied with nutrient types and taxonomic groups.
View Article and Find Full Text PDFNitrogen (N) immobilization (Nim, including microbial N assimilation) and plant N uptake (PNU) are the two most important pathways of N retention in soils. The ratio of Nim to PNU (hereafter Nim:PNU ratio) generally reflects the degree of N limitation for plant growth in terrestrial ecosystems. However, the key factors driving the pattern of Nim:PNU ratio across global ecosystems remain unclear.
View Article and Find Full Text PDFThe impacts of wildfire on vegetation and soil erosion have been studied for decades aiming to bring back ecosystems after fire perturbance. However, the influence of fires on above and belowground biodiversity remains far less understood. Biodiversity is critical for supporting ecosystem function, and this data scarcity is hampering managers in adopting effective practices for a proper restoration of burned ecosystems.
View Article and Find Full Text PDFGrazing exclusion alters grassland soil aggregation, microbiome composition, and biogeochemical processes. However, the long-term effects of grazing exclusion on the microbial communities and nutrient dynamics within soil aggregates remain unclear. We conducted a 36-year exclusion experiment to investigate how grazing exclusion affects the soil microbial community and the associated soil functions within soil aggregates in a semiarid grassland.
View Article and Find Full Text PDFIntroduction: Soil bacteria play a crucial role in the terrestrial nitrogen (N) cycle by fixing atmospheric N, and this process is influenced by both biotic and abiotic factors. The diversity of N-fixing bacteria (NFB) directly reflects the efficiency of soil N fixation, and the diversity of NFB in degraded alpine meadow soil may change with different N fertilizing levels and varied slopes. However, how N addition affects the diversity of NFB in degraded alpine meadows, and whether this influence varies with slope, remain poorly understood.
View Article and Find Full Text PDFBiochar has been shown to reduce soil greenhouse gas (GHG) and increase nutrient retention in soil; however, the interaction between biochar and organic amendments on GHG emissions remain largely unclear. In this study, we collected 162 two-factor observations to explore how biochar and organic amendments jointly affect soil GHG emissions. Our results showed that biochar addition significantly increased soil CO emission by 8.
View Article and Find Full Text PDFThe decomposition of litter and the supply of nutrients into and from the soil are two fundamental processes through which the above- and belowground world interact. Microbial biodiversity, and especially that of decomposers, plays a key role in these processes by helping litter decomposition. Yet the relative contribution of litter diversity and soil biodiversity in supporting multiple ecosystem services remains virtually unknown.
View Article and Find Full Text PDFIn this Letter, we demonstrate and experimentally verify the application of three-core photonic crystal fiber (3C-PCF) for the in-line detection of fully polarized states. We prove the response of 3C-PCF to full-polarization states under multi-core polarization interference through experiments. The sensitivity at 1472 nm is 0.
View Article and Find Full Text PDFRoot exudates are an important pathway for plant-microbial interactions and are highly sensitive to climate change. However, how extreme drought affects root exudates and the main components, as well as species-specific differences in response magnitude and direction, are poorly understood. In this study, root exudation rates of total carbon (C) and its components (e.
View Article and Find Full Text PDFSci Total Environ
March 2023
Multiple lines of existing evidence suggest that increasing CO emission from soils in response to rising temperature could accelerate global warming. However, in experimental studies, the initial positive response of soil heterotrophic respiration (R ) to warming often weakens over time (referred to apparent thermal acclimation). If the decreased R is driven by thermal adaptation of soil microbial community, the potential for soil carbon (C) losses would be reduced substantially.
View Article and Find Full Text PDFThe ability to accurately and cost-friendly monitor heavy metals in environmental solutions such as drinking or tap water is of great significance to the human health. We report a twisted fiber-based sensing mechanism that can realize highly accurate detection of Cd concentration in water solution. The basic design is a twisted single-core fiber simply coated with a propylene thiourea membrane that can absorb Cd.
View Article and Find Full Text PDFSci Total Environ
December 2022
Plants may slow global warming through enhanced growth, because increased levels of photosynthesis stimulate the land carbon (C) sink. However, how climate warming affects plant C storage globally and key drivers determining the response of plant C storage to climate warming remains unclear, causing uncertainty in climate projections. We performed a comprehensive meta-analysis, compiling 393 observations from 99 warming studies to examine the global patterns of plant C storage responses to climate warming and explore the key drivers.
View Article and Find Full Text PDFBiomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Yet, our knowledge regarding warming effects on root: shoot ratio (R/S) remains limited. Here, we present a meta-analysis encompassing more than 300 studies and including angiosperms and gymnosperms as well as different biomes (cropland, desert, forest, grassland, tundra, and wetland).
View Article and Find Full Text PDFGrazing and global change (e.g., warming, nitrogen deposition, and altered precipitation) both contribute to biodiversity loss and alter ecosystem structure and functioning.
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