Biomass Distribution Research Articles

Economic valuation of carbon sequestration in Quito’s Metropolitan Park using Sentinel-2 and neural networks

This study introduces an innovative method for assessing the economic value of carbon stored by the urban park forest in Quito, Ecuador. The method uses Sentinel-2 remote sensing data and advanced deep learning techniques. A large forest study area was chosen, and detailed field measurements were taken to gather biomass and carbon data. Sentinel-2 satellite images were processed to correct for radiation and atmospheric conditions, and vegetation indices such as NDVI and EVI were calculated. To model forest biomass, a convolutional neural network (CNN) was created and trained using Sentinel-2 spectral bands and vegetation indices. The model was validated with independent field data and demonstrated high accuracy in estimating biomass and carbon, as indicated by evaluation metrics like RMSE and R². The findings include detailed maps showing the spatial distribution of biomass and carbon in the study area, which can be a valuable tool for forest management and the implementation of policies for valuing stored carbon. This approach combines the high resolution of Sentinel-2 data with the predictive power of neural networks, providing a robust and scalable method for estimating carbon across large forest areas. The study's conclusions emphasize the feasibility and accuracy of this approach and its potential for application in various forestry and geographical contexts.

Self‐organised pattern formation promotes consumer coexistence by fluctuation‐dependent mechanisms

Abstract In spatially extended ecosystems, habitat heterogeneity facilitates coexistence of species if each competitor experiences environmental conditions in a particular habitat that provide a growth advantage compared to other species, thereby making it locally competitively superior. If the competitive hierarchy among species is the same everywhere, heterogeneity‐facilitated coexistence is possible provided that superior competitors disperse maladaptively towards unfavourable habitats or if they hedge insufficiently against fluctuating environmental conditions. We use a generic two‐patch metacommunity model to show that the latter mechanisms also operate in metacommunities with homogeneous habitat quality when heterogeneous biomass distributions emerge from self‐organised pattern formation. The model consists of an abiotic resource, an autotroph producer and two competing heterotroph consumer species of which one is always competitively inferior to the other, irrespective of resource availability. If the induced biomass patterns are static in time, a lower dispersal rate can allow the inferior competitor to avoid competitive exclusion by retaining most of its biomass in the patch with the higher resource density. However, if the biomass patterns fluctuate spatio‐temporally, the inferior competitor must adopt a higher dispersal rate than the superior competitor to persist. This increased movement enables the inferior competitor to effectively distribute its biomass across space, thereby achieving a higher growth rate during periods of recovery from local population minima. Strikingly, we find a novel coexistence mechanism that emerges if the competitors differ in their abilities to induce pattern formation. Similar to relative nonlinearity in resource use (based e.g. on a gleaner–opportunist trade‐off), the dominant species modifies the spatial or spatio‐temporal variation in the distribution of the resource in a way that favours its competitor. This prevents competitive exclusion due to differently effective dispersal strategies. We conclude that while temporal instabilities that cause, for example, predator–prey oscillations are usually regarded as jeopardising species' persistence, spatial instabilities that give rise to self‐organised pattern formation should be interpreted more positively, as they provide a generic mechanisms for maintaining diversity in metacommunities without requiring a priori habitat heterogeneity. Read the free Plain Language Summary for this article on the Journal blog.

Combining in situ and ex situ plankton image data to reconstruct zooplankton (>1 mm) volume and mass distribution in the global ocean

Abstract Plankton size spectra are important indicators of the ecosystem state, yet such measurements are typically biased by the available sampling methods. Here, we combined individual size measurement from two zooplankton imaging approaches—in situ observation by the Underwater Vision Profiler5 and Multinet-collection supplemented by ex situ imaging via Zooscan—obtained in the global ocean, to calculate zooplankton normalized biovolume size spectra (NBSS) for all organisms larger than 1 mm. The reconstructed NBSS combining both datasets resulted in increased biomass estimates by adding organisms poorly sampled by either of the methods. The optimal values measured by both methods are used to reconstruct the zooplankton biovolume and biomass distributions. The reconstructed slopes appeared steeper and closer to those measured only by the UVP5 (+7.6%) and flatter than those obtained only from the Multinet (−20%), particularly in tropical and temperate latitudes. The main difference in tropical and temperate NBSS from the two devices is due to the fragile rhizarians that were not accounted for when using net data. When possible, we suggest using in situ and ex situ technologies together, and we provide potential indications on how to correct for missing components of the community when only one method is available.

Managing fire‐prone forests in a time of decreasing carbon carrying capacity

Changing climatic conditions are increasing overstory tree mortality in forests globally. This restructuring of the distribution of biomass is making already flammable forests more combustible, posing a major challenge for managing the transition to a lower biomass state. In western US dry conifer forests, tree density resulting from over a century of fire‐exclusion practices has increased the risk of high‐severity wildfire and susceptibility to climate‐driven mortality. Reducing dead fuel loads will require new approaches to mitigate risk to the remaining live trees by preparing forests to withstand future wildfire. Here, we used data from the Teakettle Experimental Forest in California to evaluate different prescribed fire burn frequencies and their impact on accumulated dead fuels after a 4‐year drought. Increasing burn frequency could reduce surface fuel build‐up but comes with additional challenges that will require creativity and experimentation to overcome.

Drivers of microbial carbon biomass variability in two oceanic regions of the Gulf of Mexico

The microbial plankton community is an integral part of the pelagic ecosystem. It hosts essential functional groups that play a vital role in organic carbon production, release, uptake, and degradation within open-ocean ecosystems. Given its significance, carbon biomass estimates are urgently needed, especially in oligotrophic regions, to provide and enhance our knowledge of biogenic carbon pools. They also aid in validating biogeochemical models that characterize the functioning of these extensive marine ecosystems within the global carbon cycle. This study addresses the temporal variability of microbial community biomass in two oceanic zones: the west-central (Perdido) and southern (Coatzacoalcos) areas of the Gulf of Mexico. During three seasonally contrasting periods (nortes, rainy, and dry seasons), seawater samples were collected from the euphotic zone in both regions to estimate the carbon biomass of different pico- (<2–3 µm), nano-, and microplankton groups (>3–200 µm). Carbon biomass assessments for the microbial groups were based on their abundance and carbon conversion factors. Overall, we found a significant contribution of pico-prokaryotic components (heterotrophic bacteria, Prochloroccocus, and Synechoccocus) to the total microbial carbon stock of the euphotic zone (84–89 % global estimates). The finding suggests these microorganisms are key functional groups that drive carbon production and fate in the Gulf of Mexico ecosystem. Pico-cyanobacteria, especially Prochloroccocus, were the dominant primary producers (68–82 % total autotrophic carbon), mainly in the upper layer of the oligotrophic euphotic zone. This vertical pattern implies that the deep chlorophyll-a maximum (DCM) depth level was unrelated to a net increase in phytoplankton biomass in the three study periods. The distribution of microbial carbon biomass exhibited striking differences associated with winter mixing (the nortes season), high river discharge accompanied by cross-shelf transport (the rainy season), and the dynamics of mesoscale structures. Ecological aspects, such as the habitat preference of the organisms and the seasonal complementary development of mixotrophic and heterotrophic grazers and their prey, were also essential drivers in regulating the microbial carbon pool of both oceanic regions. The microbial carbon assessments conducted in this study contribute to identifying and quantifying key planktonic functional groups involved in the biogeochemical carbon cycle in the Gulf of Mexico open-ocean ecosystem.

Topography and life stage regulate species aboveground biomass distribution in combination in a tropical montane rainforest.

Understanding the correlation between topography, species biomass and species life stage would allow forest managers to better foster carbon storage in forests. Using census data from a 60-ha plot in south China, we first quantified aboveground biomass (AGB) and how much it varied among different topographies. Next, the specific contribution of 42 dominant species to total aboveground biomass was analyzed for each of the different topographies. We also explored whether these species-topography associations changed, in terms of species' AGB distribution, during each of the three life stages (sapling, juvenile, adult) for these 42 species. Our results showed that the average AGB was 368.79 Mg ha-1 and that it varied noticeably among the four topographies (Low valley, Slope, High valley and Ridge, which were classified by using fuzzy C-mean clustering based on elevation, convexity, and slope). AGB was significantly lower in the two valleys than in the two other topographies. Of the 42 species, 88.1% showed topographic preferences, and 78.6% appeared to exhibit topographic preferences that changed with life stage. Our work highlights the importance of topography and life stage in species biomass distribution and suggests that different combinations of species and life stages, based on species topographic preferences across life stages, may be better suited in different tropical rainforest topographies to maximize carbon storage overall.

Effects of plant nutrient acquisition strategies on biomass allocation patterns in wetlands along successional sequences in the semi-arid upper Yellow River basin.

The ecological environment of wetlands in semi-arid regions has deteriorated, and vegetation succession has accelerated due to climate warming-induced aridification and human interference. The nutrient acquisition strategies and biomass allocation patterns reflect plant growth strategies in response to environmental changes. However, the impact of nutrient acquisition strategies on biomass allocation in successional vegetation remains unclear. We investigated 87 plant communities from 13 wetland sites in the semi-arid upper Yellow River basin. These communities were divided into three successional sequences: the herbaceous community (HC), the herbaceous-shrub mixed community (HSC), and the shrub community (SC). The nutrient composition of stems and leaves, as well as the biomass distribution above and belowground, were investigated. Results revealed that aboveground biomass increased with succession while belowground biomass decreased. Specifically, SC exhibited the highest stem biomass of 1,194.53 g m-2, while HC had the highest belowground biomass of 2,054.37 g m-2. Additionally, significant positive correlations were observed between leaf and stem biomasses in both HC and SC. The nitrogen (N) and phosphorus (P) contents within aboveground parts displayed an evident upward trend along the succession sequence. The highest N and P contents were found in SC, followed by HSC, and the lowest in HC. Stem N was negatively correlated with stem, leaf, and belowground biomass but positively correlated with root-shoot ratio. Leaf P displayed positive correlations with aboveground biomass while showing negative correlations with belowground biomass and root-shoot ratio. The ratios of C:N, C:P, and N:P in stem and leaf exhibited positive correlations with belowground biomass. The random forest model further demonstrated that stem N and leaf P exerted significant effects on aboveground biomass, while leaf P, stem N and P, and leaf C:P ratio had significant effects on belowground components. Additionally, the root-shoot ratio was significantly influenced by leaf P, leaf C:P ratio, and stem N, P, and C:P ratio. Therefore, the aboveground and belowground biomasses exhibited asynchronism across successional sequences, while plant nutrient acquisition strategies, involving nutrient levels and stoichiometric ratios, determined the biomass allocation pattern. This study offers valuable insights for assessing vegetation adaptability and formulating restoration plans in the semi-arid upper Yellow River basin.

Effects of Mesozooplankton Growth and Reproduction on Plankton and Organic Carbon Dynamics in a Marine Biogeochemical Model

AbstractMarine mesozooplankton play an important role for marine ecosystem functioning and global biogeochemical cycles. Their size structure, varying spatially and temporally, heavily impacts biogeochemical processes and ecosystem services. Mesozooplankton exhibit size changes throughout their life cycle, affecting metabolic rates and functional traits. Despite this variability, many models oversimplify mesozooplankton as a single, unchanging size class, potentially biasing carbon flux estimates. Here, we include mesozooplankton ontogenetic growth and reproduction into a 3‐dimensional global ocean biogeochemical model, PISCES‐MOG, and investigate the subsequent effects on simulated mesozooplankton phenology, plankton distribution, and organic carbon export. Utilizing an ensemble of statistical predictive models calibrated with a global set of observations, we generated monthly climatologies of mesozooplankton biomass to evaluate the simulations of PISCES‐MOG. Our analyses reveal that the model and observation‐based biomass distributions are consistent ( = 0.40, total epipelagic biomass: 137 TgC from observations vs. 232 TgC in the model), with similar seasonality (later bloom as latitude increases poleward). Including ontogenetic growth in the model induced cohort dynamics and variable seasonal dynamics across mesozooplankton size classes and altered the relative contribution of carbon cycling pathways. Younger and smaller mesozooplankton transitioned to microzooplankton in PISCES‐MOG, resulting in a change in particle size distribution, characterized by a decrease in large particulate organic carbon (POC) and an increase in small POC generation. Consequently, carbon export from the surface was reduced by 10%. This study underscores the importance of accounting for ontogenetic growth and reproduction in models, highlighting the interconnectedness between mesozooplankton size, phenology, and their effects on marine carbon cycling.

Distribution of Woody Biomass on the Outwash Plain of a Retreating Glacier in Southern Iceland: Role of Microhabitat and Substrate

The Skaftafellsjökull is an outlet glacier in southern Iceland that has been retreating since 1890. While multiple studies have examined primary succession on the foreland of this glacier, no study has examined the distribution of woody biomass on the outwash plain. We investigated the distribution of one species, Betula pubescens, that grows on the foreland moraines and outwash plain of this glacier. The topography of the outwash plain is heterogeneous, consisting of broad bars of outwash gravel and boulders that are separated by narrow incised channels and broader swales. Vegetation on the outwash plain is primarily a moss–heath community. Birch are sparse on the outwash bar tops, but are more abundant and larger in the channels and swales between the bars. Although the area of the channels on the outwash plain is much less than that of the bar surfaces, the woody biomass of the outwash plain is dominated by the birch within these channels. Consequently, the mean woody biomass of the outwash plain exceeds that of the moraines. We propose that the microhabitat of the outwash plain channels provides a favorable environment for the growth of birch, primarily by providing a fine-grained substrate that promotes successful seeding and growth.

Nitrogen deposition enhances the competitive advantage of invasive plant species over common native species through improved resource acquisition and absorption

BackgroundPrevious studies into the interactions between native and invasive species under nitrogen (N) deposition have often overlooked the presence of co-occurring native species, a factor that could influence the outcomes of interspecific competition. Furthermore, publication bias may lead researchers to focus on rare native species with limited adaptability. In this study, we examined how two levels of N deposition affected the physiological and ecological traits and the interspecies interactions between three invasive and three common native species.ResultsN deposition promoted the growth of both invasive and native species. The relative dominance index (RDI) of invasive species was consistently higher than that of native species. Invasive species had an advantage over common native species in using the increased N effectively. The biomass distribution of invasive species was biased toward the aboveground parts, indicating competition for light resources.ConclusionsN deposition conferred a stronger competitive advantage to invasive species than to native species, suggesting that the distribution range of invasive species may expand further under increased N deposition.

A dataset of individual wet weights of benthic macroinvertebrates

AbstractBiomass estimates are crucial for modeling and understanding energy flow through ecosystems. Many modeling frameworks rely on published body weights of organisms to convert density estimates to biomass. However, published body weight data are limited to few taxa in a limited number of systems. Here we present mean individual weights for common benthic macroinvertebrates of the Laurentian Great Lakes from over 2000 benthic samples and 8 yr of data collection. We also compiled wet to dry weight conversions to facilitate data reuse for researchers interested in dry weight. We compared our benthic invertebrate weights to other lakes, demonstrating when weight measurements may be applied outside the Great Lakes. Sensitivity analyses supported the robustness of our calculations. Our dataset is applicable to food web energy flow models, calculation of secondary production, interpretation of trophic markers, and for understanding how biomass distribution varies by benthic invertebrate species in the Great Lakes.

Distribution of pelagic and demersal fish assemblages by video prospection in the archipelago of Fernando de Noronha

This study presents an approach that complements previously identified trends in the distribution of acoustic biomass of demersal and pelagic fishes in Fernando de Noronha. Using underwater video as the main method of analysis, patterns of relative fish abundance were evaluated as indicators of biomass, richness, and trophic levels of demersal and pelagic assemblages. Thus, depth stratum, Marine Protected Area (MPA) including the National Marine Park and the Sustainable Fishing Zone, and oceanographic/abiotic factors (e.g., winds, currents, and substrate complexity) were considered. The results confirm that complex substrates and shallow areas (0–20 m) are characterised by greater abundance and species richness. However, it is important to note the limitation of video in detecting fish in deeper areas. Wind exposure also positively influences the abundance and diversity of demersal fish, demonstrating the impact of the "island effect" on species distribution. The research also highlights the relevance of the MPA in Fernando de Noronha for both biodiversity conservation and the sustainability of fishing activities. However, the analysis of trophic levels revealed an increased prevalence of higher trophic levels outside the MPA, mainly due to the abundance of the species Melichthys niger. The presence of complex substrates and lower trophic competition may explain this observation. Therefore, the study provides important insights for the planning of MPAs and the need to include the spatial distribution of higher trophic level species for marine conservation.

A scalable and normalized reef status index for assessing fish trophic structure reveals conservation gaps

The trophic structure of ecosystems, reflecting biomass distribution across different levels, is paramount for understanding energy dynamics and community assemblages in marine environments. Typically, ecosystems devoid of external energy influx exhibit a bottom-heavy trophic pyramid, yet higher biomass systems often display a top heavy or concave distribution. Such structures are susceptible to alterations due to species turnover, trophic cascades, and anthropogenic impacts, particularly the phenomenon of ’Fishing down’ the food web. Recognizing the trophic structure as a simplified yet potent indicator, we identify the necessity for a standardized, expedient method to assess reef health—a criterion fulfilled by our Normalized Reef Status Index (NRSI). The NRSI offers a novel metric for scientists and conservation practitioners to augment traditional reef health assessments. Utilizing the NRSI, we assessed the ecological status of 346 reefs across the Mexican Pacific. Our results demonstrated that only reefs within Fully Protected areas conform to the concave trophic structure indicative of low human interference. In stark contrast, unprotected reefs exhibited a depleted trophic architecture, often devoid of apex predators. This depletion not only threatens coastal livelihoods and food security but also disrupts the delicate balance of marine ecosystems critical to sustaining global ecological functions. Through the NRSI, we provide a robust, scalable tool for ongoing monitoring and conservation efforts, underscoring the urgent need to address human-induced trophic disruptions.

Growth and Biomass Distribution in Cocoa Varieties under Different Nitrogen Regimes

Among the 17 vital plant nutrients, nitrogen (N) is crucial in crop production. It extensively enhances the growth and biomass production of plants by improving photosynthesis and protein synthesis. To study the impact of three different N levels (40, 80, and 120 ppm) on the growth and biomass production of eight cocoa varieties, a hydroponic experiment was carried out at ICAR-CPCRI, Regional Station, Vittal. The results showed that increasing N concentration significantly boosted growth and biomass production. Among the different varieties, VTLCH-1 exhibited the highest plant height, maximum number of leaves, greater stem diameter, and the highest total fresh biomass with the application of 120 ppm nitrogen. Biomass partitioning analysis revealed that higher N levels increased leaf and stem biomass while reducing root biomass, leading to a higher shoot-to-root ratio. This indicates that N application influences the biomass production and distribution in the plant.

Optimization of nitrogen and phosphorus fertilization for enhanced forage production and quality of Festuca Krylovianacv. Huanhu artificial grassland in alpine regions

Artificial grasslands of F. kryloviana in the region surrounding Qinghai Lake have been observed to a decline in productivity following three years of establishment. Traditional fertilization practices, aimed at maintaining ecological balance, have predominantly focused on the application of phosphorus. However, it remains unclear whether phosphorus fertilizers offer a superior advantage over nitrogen fertilizers in sustaining productivity. Consequently, from 2017 to 2019, we conducted an experimental to assess the impact of nitrogen and phosphorus fertilization on forage yield and quality. We designed with four levels of phosphorus and two levels of nitrogen, resulting in eight distinct fertilizer combinations. Our experimental findings indicate that the degradation of artificial grasslands leads to a shift in the allocation pattern of aboveground biomass. There was a respective decrease of 68.2 % and 62.5 % in the biomass proportions of stems and ears, contrasted by a greater than 200 % increase in the biomass proportion of leaves. The application of nitrogen not only elevated the total aboveground biomass but also promoted a preferential allocation of biomass to stems and leaves, consequently enhancing the forage's crude protein content. Nitrogen fertilization significantly increased aboveground biomass, and crude protein content by 63.21 %, and 6 %, respectively. Phosphorus fertilization's impact varied annually but favored the distribution of biomass to stems and ears. The net photosynthetic rate improved by over 53.12 % with fertilizer application, although the differences among treatments were not statistically significant. The balanced application of nitrogen and phosphorus fertilizers significantly bolstered the aboveground biomass, ear biomass, stem biomass, leaf biomass, and crude protein content in varying years by 17.25 %–209.83 %, 34.7 %–438.9 %, 25.5 %–250.2 %, 18.4 %–133.3 %, and 10.21 %–25.62 %, respectively. Our analysis revealed that nitrogen-only fertilization exhibited the most optimal fertilizer use efficiency and economic returns. In conclusion, nitrogen fertilization is crucial for sustaining the productivity and quality of F. kryloviana artificial grasslands. The local practice of 75 kg ha−1 phosphorus fertilizer is detrimental to the maintenance of productivity in F. kryloviana artificial grasslands. This study offers valuable insights into the optimization of fertilization strategies for sustainable forage production within alpine regions.

Root foraging strategies and niche segregation of three mediterranean shrub species

Shrubs are usually adapted to stressful environments in which soil resources are limited, and thus, roots are fundamental for their biological success. However, root measures are challenging to collect, especially in field conditions and at the individual level. For this study, we collected data on the three‐dimensional distribution of fine root biomass of twenty‐three individuals belonging to three shrub species in a mediterranean shrubland in central Spain: gum rockrose Cistus ladanifer, rosemary Salvia rosmarinus, and hairy‐fruited broom Cytisus striatus. Our goal was to determine the soil‐foraging strategies adopted by the plants. We hypothesized that plants would show stabilizing niche differences explaining the high plant biodiversity characteristic of mediterranean shrublands and that they would follow the game theory model's prediction of exploitative segregation of roots behaving territorially but also over‐proliferating roots close to their stem and engaging in a root tragedy of the commons. We found that two‐thirds to three‐fourths of the biomass was belowground, and the system's productivity was roughly 500–600 g C m−2 year−1. Only rosemary plants competed with neighbors following the exploitative segregation predictions. Broom plants had the shallowest and most widespread root systems but significantly reduced their root range toward competing neighbors. Gum rockrose presented deep, narrow root systems avoiding extensive overlap with neighbors but did not appear to respond to competitive pressure levels. Shrubs appeared to stratify their roots at different soil depths, supporting the niche segregation hypothesis.

Impacts of estuarine habitat degradation on the modeled life history of marine estuarine-dependent and resident fish species.

Shallow coastal and estuarine habitats play an essential role in the life cycles of many fish species, providing spawning, nursery, feeding, and migration areas. However, these ecologically valuable habitats are increasingly threatened by anthropogenic activities, causing substantial changes in both habitat availability and quality. Fish species use these shallow coastal habitats and estuaries during various life stages, leading to their categorization into guilds based on how and when they rely on these areas. This differential functional use of estuaries means that changes to these habitats may affect each guild differently. To understand the impact of estuarine habitat degradation on fish populations, it is therefore necessary to consider the full life cycle of fish and when they rely on these coastal habitats. Here, we use conceptual size-structured population models to study how estuarine habitat degradation affects two functionally different guilds. We use these models to predict how reduced food productivity in the estuary affects the demographic rates and population dynamics of these groups. Specifically, we model estuarine residents, which complete their entire life cycle in estuaries, and marine estuarine-dependent species, which inhabit estuaries during early life before transitioning offshore. We find that total fish biomass for both guilds decreases with decreasing food productivity. However, the density of juveniles of the marine estuarine-dependent guild can, under certain conditions, increase in the estuary. This occurs due to a shift in the population biomass distribution over different life stages and a simultaneous shift in which life stage is most limited by food. At the individual level, somatic growth of juveniles belonging to the estuarine-dependent guild decreased with lower food supply in the estuary, due to increased competition for food. The somatic growth rates of fish belonging to the resident guild were largely unaffected by low food supply, as the total fish density decreased at the same time and therefore the per-capita food availability was similar. These outcomes challenge the assumption that responses to habitat degradation are similar between fish guilds. Our study highlights the need to assess not only fish biomass but also size distributions, survival, and somatic growth rates for a comprehensive understanding of the effects of habitat degradation on fish populations. This understanding is crucial not only for estuary fish communities but also for successful conservation and management of commercially harvested offshore population components.

Assessing Golden Tides from Space: Meteorological Drivers in the Accumulation of the Invasive Algae Rugulopteryx okamurae on Coasts

Massive accumulations of invasive brown algae Rugulopteryx okamurae are exacerbating environmental and socio-economic issues on the Mediterranean and potentially Atlantic coasts. These golden tides, likely intensified by global change processes such as changes in wind direction and intensity and rising temperatures, pose increasing challenges to coastal management. This study employs the Normalized Difference Vegetation Index (NDVI), with values above 0.08 from Level-2 Sentinel-2 imagery, to effectively monitor these strandings along the coastline of Los Lances beach (Tarifa, Spain) in the Strait of Gibraltar Natural Park from 2018 to 2022. Los Lances beach is one of the most affected by the R. okamurae bioinvasion in Spain. The analysis reveals that wind direction determines the spatial distribution of biomass accumulated on the shore. The highest average NDVI values in the western patch were observed with south-easterly winds, while in the eastern patch, higher average NDVI values were recorded with south-westerly, westerly and north-westerly winds. The maximum coverage correlates with elevated temperatures and minimal rainfall, peaking between July and October. Leveraging these insights, we propose a replicable methodology for the early detection and strategic pre-shore collection of biomass, which could facilitate efficient coastal cleanup strategies and enhance biomass utility for biotechnological applications. This approach promises cost-effective adaptability across different geographic areas impacted by golden tides.

Simulating vertical distribution of normalized leaf biomass for individual Moso bamboos under intensive management

Leaf biomass is a crucial parameter that influences forest growth and carbon exchange between ecosystems and the atmosphere. A clear understanding of the vertical distribution of leaf biomass is essential for accurate carbon sequestration estimations in Moso bamboo. We collected data on leaf biomass from each crown layer and the structural characteristics of 54 individual Moso bamboo plants. We then simulated the vertical distribution of normalized upward cumulative leaf biomass (CLBn) using three power functions. The first model (Model 1) estimates CLBn using unique and unadjustable parameters (a and b) of the power function. In the second model (Model 2), parameter ‘a’ was fixed at 1, and parameter ‘b’ was fitted for all samples. In the third model (Model 3), parameter b was adjusted based on the structural characteristics of each bamboo. Model 3 demonstrated the highest accuracy in estimating CLBn and normalized leaf biomass (LBn) in each layer, with RMSEr values of 20.34 % and 36.85 % for CLBn and LBn, respectively. When compared with Model 1 and Model 2, Model 3 reduced RMSEr by 12.27 % and 6.88 % for CLBn and 21.13 % and 10.49 % for LBn, respectively. However, uncertainty remained significant in low LBn estimates from Model 3. Variations in the vertical distribution of CLBn in individual bamboo plants were primarily explained by crown length, height to the lowest living branch, and age. This study proposes a viable method for elucidating the variation in CLBn among individual bamboo plants.

Investigating the adsorption mechanism of zinc chloride-modified porous carbon for sulfadiazine removal from water

Abstract Sulfadiazine (SDZ) is a commonly used antibiotic in medicine, aquaculture, and animal husbandry. However, its misuse has resulted in its release into soil and water environments, posing a gradual threat to the environment and human health. In this study, cotton pulp, poplar sawdust, and corn stover were chosen as raw materials. Zinc chloride (ZnCl2) was used as a modifier to prepare modified porous carbon through pyrolysis at different carbonization temperatures (400 and 800°C). The objective was to investigate the adsorption effect and mechanism of modified porous carbon on SDZ in aqueous environments, as well as the effect of different biomass fractions of the carbon source on the adsorption effect. The physical and chemical properties of the modified porous carbon were characterized by various means of characterization, and the results showed that the high temperature and modification effects made the adsorbent material possess a larger specific surface area and richer pore structure, higher aromaticity, higher degree of graphitization, etc., which would be beneficial for the adsorption of SDZ. Among them, CCPZ800 showed the highest saturation adsorption of SDZ, Q max = 425.45 mg/g. The adsorption experiments were carried out by changing the initial conditions and fitted with kinetic and isothermal adsorption to further explain the adsorption mechanism of modified porous carbon on SDZ in conjunction with the adsorption of SDZ by hydrothermal carbon materials. The results showed that the adsorption of modified porous carbon on SDZ conformed to the quasi-secondary kinetic and Freundlich isothermal adsorption models. Adsorption mechanism of SDZ on modified porous carbon followed a multimolecular layer adsorption, with chemical adsorption being the dominant process. Both physical adsorption and chemical adsorption occurred simultaneously, with the main adsorption mechanism being π–π conjugation. In addition, compositional distribution of biomass from different carbon sources results in variations in pyrolysis mode and pyrolysis products, which in turn affect adsorption. By analyzing the effect of variability in the composition of biomass on the adsorption effect of SDZ, it can be concluded that higher cellulose content in the carbon source leads to a better adsorption effect of SDZ. The study showcases the effectiveness of ZnCl2-modified porous carbon in removing SDZ from water, offering insights into the selection of raw materials for this adsorbent preparation.