Average Biomass Research Articles

Remote sensing and spatial analysis reveal unprecedented cyanobacteria bloom dynamics associated with elephant mass mortality.

The 2020 mass mortality of 350 African elephants (Loxodonta africana) in Botswana sparked global concern, with cyanotoxins in watering holes (pans) being a suspected cause, though evidence remains inconclusive. Combining remote sensing and spatial analysis, we examined the relationship between the ecohydrology of ~3000 pans and the locations of deceased elephants. Our analysis revealed a significant difference in the spatial distribution of fresh versus decayed carcasses (p < 0.001), indicating that the die-off deviated from typical regional elephant mortality patterns. We identified 20 pans near fresh carcasses that experienced increased cyanobacteria bloom events in 2020 (n = 123) compared to the previous 3 years combined (n = 23), exhibiting the highest average phytoplankton biomass of the period 2015-2023 (Normalised Difference Chlorophyll Index >0.2). These findings suggest a heightened risk and likelihood of cyanotoxin presence in these pans. Elephants were estimated to have walked 16.5 km (± 6.2 km) and died within 88 h (± 33 h) of exposure. Our study provides evidence that cyanobacterial toxicity could be a contributing factor to the 2020 die-off, while also considering other potential causes, and offers a general framework for investigation of future mortality events. We underscore the need to integrate spatial analysis and regional ecohydrological assessments to monitor and mitigate animal mortality events and inform conservation strategies.

Unveiling Ecosystem Shifts in the Southern Benguela Through Otolith Biochronologies of Sardine (Sardinops sagax)

ABSTRACTSardine (Sardinops sagax) in the southern Benguela has shown substantial changes in population size over the past 70 years. Heavy fishing pressure in the 1950s to early 1970s caused the collapse of sardine stocks in South Africa. A fishery collapse happens because of significant alterations in the marine community, hindering the recovery of valuable commercial species and leading to cascading effects across multiple trophic levels in marine food webs. In this study, a robust 58‐year biochronology (1962–2019) was developed using archived sardine otoliths from the West of Cape Agulhas in South Africa. Sequential t‐test analysis of regime shifts (STARS) performed on the biochronology of fish growth indicated four regimes with three alteration points in 1986, 2006 and 2015 that correspond with periods of low, high, average and low biomass, respectively; that is, high growth rates occurred during the high biomass period and vice versa. A series of mixed effects models was developed to determine increment width response to selected environmental, prey availability and sardine biomass factors based on the assumption that otolith increment growth is a proxy for somatic growth. Predicted sardine growth positively correlated with sardine biomass, sea surface temperature and copepod abundance estimates. This observation suggests that sardine population dynamics exhibit a depensation mechanism, potentially destabilizing populations after the fishery collapse. Sea surface temperature and copepod abundance have been primary factors influencing sardine growth, partly because of depensatory population dynamics. Furthermore, the study improves understanding of how different factors have affected sardine growth following the collapse of the sardine fishery.

Optimized Liquid Medium Formulation for Sanghuangporus vaninii and Biological Activity of the Exopolysaccharides

Aims: Sanghuangporus vaninii (S. vaninii) is a rare medicinal mushroom that is rich in polysaccharides, triterpenes, flavonoids, and other bioactive compounds. It has good potential development value. Methods and Results: We performed single factor experiments and Box-Behnken response surface methodology to optimize the liquid fermentation medium formulation for S. vaninii with mycelial biomass as the indicator. The in vitro antioxidant and anti-cancer capacity of the exopolysaccharides of S. vaninii were estimated. The optimal liquid fermentation media composition for the MS-4, MS-6, and MS-8 strains of Sanghuangporus vaninii consisted of 25.86 ± 0.068 g/L maltose, 7.3 ± 0.043 g/L yeast extract, and 0.71 ± 0.005 g/L dandelion powder. The average mycelial biomass of S. vaninii under optimal conditions was 12.61 g/L. The mycelial biomass of the Sanghuangporus vaninii strains in the optimized formulation was 109–191% higher than that obtained with the basic potato dextrose broth (PDB). The exopolysaccharides of Sanghuangporus vaninii exhibited an ABTS radical scavenging activity with an EC50 of 0.021 ± 0.017 mg/mL and a DPPH radical scavenging activity with an EC50 of 0.076 ± 0.043 mg/mL. In anti-cancer assays, these exopolysaccharides demonstrated an IC50 value of 1.98 ± 0.36 mg/mL against PC-3 human prostate cancer cells, indicating significant bioactivity, highlighting their potential as functional food ingredients. Conclusions: In this study, the formula of liquid fermentation of S. vaninii strains was optimized, which lays a theoretical foundation for increasing the yield of S. vaninii and its application in industry. Moreover, our data showed the clinical potential of the S. vaninii exopolysaccharides as antioxidants and anti-cancer drugs.

Effect of Plant Identity in Wheat Mixtures on English Grain Aphid (Sitobion avenae) Control

ABSTRACTField experiments have demonstrated that wheat mixtures differ in their ability to regulate aphid populations. To further investigate the effectiveness of wheat mixtures (Triticum aestivum and Triticum turgidum) in controlling aphids, we conducted both laboratory and greenhouse experiments. Specifically, we assessed the associational resistance of two wheat mixtures (Florence‐Aurora with Forment, Florence‐Aurora with Montcada), and their respective monocultures, in different stages of the aphid host selection process. We analysed aphid acceptance rate, population growth, and load under different wheat treatments. Additionally, we characterised wheat aboveground biomass and nitrogen content as important functional traits for aphid resistant. Aphid acceptance decreased in plants of cv. Forment when exposed to volatiles from undamaged Florence‐Aurora plants, whereas the other tested combinations tested had no effect. Aphids performed differently in the two mixtures: Florence‐Aurora mixed with Forment significantly reduced aphid population growth and load compared to the monocultures, whereas the combination of Florence‐Aurora with Montcada wheat had no effect on aphid performance. The plant–plant interactions also modified the analysed traits. Nitrogen content of Florence‐Aurora wheat plants was reduced when mixed with Forment wheat, which may explain the lower aphid load observed in plants of cv. Florence‐Aurora when mixed with plants of cv. Forment. However, mixing wheats with similar aboveground biomass resulted in an increase in the average biomass of plants of both cultivars which could have led to a higher aphid population. The data supports the idea of right neighbour, as the benefits of wheat mixtures for aphid control were determined by the identity of the combined plants (or species). Finally, our results suggest that associating wheats with different traits may promote facilitative interactions, which in turn enhances associational resistance, whereas the combination of wheats with similar traits may result in competitive interactions that may hinder aphid control benefits.

Quantifying the rainfall variability effects on crop growth and production in the intensified annual forage - winter wheat rotation systems in a semiarid region of China

Replacing summer fallow period (July to September, SF) with annual short-season forages in the traditional fallow-winter wheat (Triticum aestivum L.) system may maintain grain yield and improve productivity in the semi-arid environments. But the uneven and variability rainfall led to instable productivity of the annual forage–winter wheat cropping system. The aims of this study were to 1) quantifying rainfall variability effects on annual forage–winter wheat system crop growing process and productivity; 2) determine the optimal annual forage–winter wheat production system that will response better to future climate change. A four-year (2016–2020) field experiment was conducted to investigate the impact of replacing summer fallow period with annual forages including oat (FO, Avena sativa L.), soybean (SB, Glycine max L.), and vetch (FV, Vicia sativa L.) on plant height (H), leaf area index (LAI), and above-ground biomass (AByield) growth index dynamics under three different levels of rainfall manipulation i.e. 30 % of ambient rainfall exclusion (R-30 %), natural rainfall (CK), and 30 % of ambient rainfall increase (R+30 %). Additionally, we assessed the correlations between forage and winter wheat production with growing season precipitation across 12 rainfall scenarios. Average forage biomass values of oat, soybean, and vetch were 5.50, 4.29, and 2.82 t ha−1, respectively during summer fallow period. The average winter wheat grain yield values in SF, FO, SB, and FV were 3.78, 3.12, 4.02, and 3.18 t ha−1, respectively. Integrating oat into fallow period had negative effects on wheat growth and production, and the H, LAI, and AByield for FO were 63.7 %, 50.9 %, and 29.9 % lower than SF in dry year, but the wheat grain yield in SB were 18.2 % and 24.8 % greater than SF in normal and wet years. Across the four growing seasons, the forage and wheat yields were shown to be strongly related to precipitation, and increasing precipitation significantly enhanced the production. In 2016–2017 growing season, LAI of wheat in SF, FO, SB, and FV with R+30 % scenario was increased by 30.2 %, 21.7 %, 32.7 %, and 19.8 % and that with R-30 % scenario decreased by 23.2 %, 17.8 %, 24.7 %, 16.5 % compared CK, respectively. The traditional summer fallow practice had advantage for maintaining stability in wheat gain production, especially under dry years. In consideration of forage and wheat production to rainfall variability, integrating soybean into fallow season may be an efficient option to maintain wheat yield and produce high forage amount under future climate change on the Loess Plateau and similar semi-arid regions.

Genome-wide association study reveals effect of nsSNPs on candidate genes in rice during iron deficiency.

Resource-poor areas with moisture deficit lands following aerobic and direct seeded rice (DSR) methods of cultivation face severe problems of iron deficiency. In this study, Bengal and Assam Aus rice panel was phenotyped at the seedling stage using an iron-deprived hydroponic medium for various shoot and root traits. A novel iron deficiency scoring scale was used to classify the tolerance reaction and could range anywhere between 0 and 9, indicating the most tolerant and susceptible, respectively. The GWAS results identified four putative candidate genes; OsFLA for number of leaves and shoot length, OsBIDK1 for root traits; average diameter, volume, biomass, projected area, and surface area, OsHPL3 for chlorophyll index of the third leaf and AKR2B (XBOS252) was for Fe score, (which was earlier reported in relation to Xa21). The nsSNP (nsSNPs) variations in these gene sequences were used to group the panel and identify superior haplotypes and donors. BR16 was identified as a superior donor, with higher chlorophyll index and shoot length than RA23, also higher values for root traits like root average diameter, root volume, root projected area and root surface area followed by Shete Bhado. The impact of identified nsSNPs on protein structure and stability was investigated. The conserved domains detected in the mutated proteins of the superior haplotypes are very informative, highlighting that natural selection favors abiotic stress tolerant variants in resource poor areas. Thus, justifying our choice of Aus landraces for association mapping of Fe deficiency tolerant genes in rice.

Photoautotrophic picoplankton of the Kara Sea in the middle of summer: Effect of first-year ice retreat on carbon and chlorophyll biomass and primary production

The Arctic warming leads to a decline in sea-ice extent and thickness, rapid warming and freshening of the sea surface which impact the distribution of phytoplankton size composition. Picophytoplankton is an ecologically important component of Arctic pelagic marine ecosystems, and its role may be altered by global warming. In this study, the abundance and biomass, the chlorophyll a (Chl-a) and primary production (PP) of picophytoplankton, and its spatial and temporal distribution were investigated in the Kara Sea during the ice-melt season in July 2019. Picophytoplankton played a major role in the surface PP in the southern and western areas of the Kara Sea. In the surface layer, the contribution of picophytoplankton to total Chl-a increased insignificantly, and the contribution of picophytoplankton to total PP decreased significantly with the time of sea ice retreat. In the euphotic zone, the Chl-a concentration of picophytoplankton and its contribution to total Chl-a decreased with the time of sea ice retreat. The average picophytoplankton biomass determined in the present study (2.72 ± 5.10 mg C m−3) corresponded to the biomass estimates in the Arctic. The picophytoplankton community was strongly dominated by eukaryotes, cyanobacteria were only detected at 3 out of 11 stations, with maximum abundances (0.07 × 109 cells m−3) observed at depths below 15 m. The obtained results contribute significantly to the study of the picophytoplankton dynamics during the ice-melting season in the hard-to-reach Kara Sea.

Мегабентос западного прибрежья архипелага Новая Земля в приловах донного трала

As a part of a marine expedition on the R/V «Dalnye Zelentsy» along the western coast of the Novaya Zemlya archipelago, an assessment of megabenthic species diversity and biomass in bycatch of trawl was carried out in August 2023 specimens of 29 taxa belonging to 6 phyla were identified during the survey. The highest species diversity (20 species) was recorded in the northern coastal area of the Novaya Zemlya archipelago, where the dominant forms in terms of biomass were sea urchins Strongylocentrotus pallidus – 237.1 kg/km2. A tendency for a 5-fold decrease in megabenthos species diversity and a decrease in the average biomass of organisms – from 17.2 to 0.47 kg/km2 was detected with transition from north to south. The association of sea urchins S. pallidus and brittle stars Gorgonocephalus sp. (84 % biomass share of representatives in bycatch) is identified in the north of the study area, which is replaced by the association of sea urchins S. pallidus and crustaceans Chionoecetes opilio (74.6 %) when moving to the south. According to the results of the RDA analysis, the effects of trawl fishing and type of water mass have the greatest impact on species diversity and biomass of megabenthic organisms. Trawling intensity, type of water mass, and sediment characteristics explain 75 % of the observed variability in these biological parameters.

Estimation of carbon stocks of woody plant species in church forests of West Gojjam zone, Northwestern Ethiopia: Implications for climate change mitigation

Forests, particularly church forests, play a crucial role in mitigating climate change by absorbing and storing CO2, preserving biodiversity, and acting as carbon sinks. This study aimed to estimate the biomass and carbon stocks of various woody species in church forests in the West Gojjam zone. Twenty-six church forests were selected based on agroecology, elevation, size, and proximity to population centers. Vegetation data were collected using a systematic sampling technique, with 20 m x 20 m (400 m2) plots established along transect lines oriented at 120° intervals at 60°, 180°, and 300° within each church forest. Measurements of diameter at breast height (DBH) and height were taken for all matured woody plants with a DBH ≥ 2.5 cm. Data analysis was performed using one-way ANOVA to evaluate the effects of altitude, forest size, and human disturbance on aboveground biomass (AGB) and carbon stocks. Additionally, linear regression was applied to investigate the relationship between vegetation structure (species richness, density, and diversity) and biomass accumulation. The results revealed a total of 111 woody species, dominated by indigenous species particularly from the Fabaceae family. The study church forests had Shannon diversity index and richness ranging from 1.73 to 3.47 and 7 to 45, respectively. The results showed that the 26 church forests had an average aboveground biomass (AGB) of 31.97 ± 3.31 tons ha-1 and a CO2 equivalence of 97.15 ± 10.47 tons ha-1. The AGB and aboveground carbon (AGC) values varied among the church forests, of which Debre Mihret Mesk Kidanemihret had the highest AGB with 99.00 tons ha-1 and 49.50 tons ha-1 AGC, indicating their substantial capacity for carbon storage. Conversely, Korch Silassie church forest displayed the lowest AGB, suggesting ecological challenges that necessitate targeted conservation efforts. These findings underscore the critical role of church forests as carbon sinks, capable of sequestering atmospheric CO2 and contributing to the mitigation of climate change. The findings of the present study suggest the integration of church forests into national and international climate policies, such as REDD+ to leverage their potential in reducing emissions from deforestation and forest degradation.

Estimation, Spatiotemporal Dynamics, and Driving Factors of Grassland Biomass Carbon Storage Based on Machine Learning Methods: A Case Study of the Hulunbuir Grassland

Precisely estimating the grassland biomass carbon storage is vital for evaluating grassland carbon sequestration potential and the monitoring and management of grassland resources. With the increasing intensity of climate change (CC) and human activities (HA), it is necessary to explore spatiotemporal variations in biomass carbon storage and its response to CC and HA. In this study, we focused on the Hulunbuir Grassland, utilizing sample plots data, MODIS data, environmental factors (terrain, soil, and climate), location factor, and texture characteristics to assess the performance of four machine learning algorithms: random forest, support vector machine, gradient boosting decision tree, and extreme gradient boosting in estimating grassland aboveground biomass (AGB). Based on the optimal model combined with root-shoot ratio data, grassland distribution data, and carbon content coefficients, the spatiotemporal characteristics and driving factors of biomass carbon storage from 2001–2022 were analyzed. The results showed that (1) the random forest achieved the highest prediction accuracy for grassland AGB, making it appropriate for AGB estimation in the Hulunbuir Grassland. (2) The spectral indices were the key variables of the grassland AGB, especially the enhanced vegetation index and difference vegetation index. (3) The 22-year average total biomass (TB) of the study area was 1037.10 gC/m2, of which the 22-year average AGB was 48.73 gC/m2 and 22-year average belowground biomass was 988.37 gC/m2, showing a spatial distribution feature of gradual increase from west to east. (4) From 2001–2022, TB carbon storage showed an insignificant growth trend (p &gt; 0.05). The 22-year average carbon storage of TB was 72.34 ± 18.07 gC. (5) Climate factors were the main driving factors for the spatial pattern of grassland TB carbon density, while the combined effects of CC and HA were the main contributors to the interannual increase in grassland TB carbon density.

Rural development through solar and pyrolysis systems: Towards energy sustainability

Rural communities require socio-economic development and technologies that lead to the deployment of renewable energy systems. For these reasons, a solar parabolic dish cooker (SPDC), solar PV and fast pyrolysis systems were developed. The fast pyrolysis system is designed to generate biogas and biochar using an average biomass consumption and the generated waste per person per day in rural areas at a feed rate of 0.65 kg. 0.157 kg of biogas (CH4, H2 and CO) was recovered at the given feed rate and 73 % of the produced biogas is expected to be handed over to the feed provider since 27 % was burnt in the pyrolyser furnace. The SPDC utilised both aluminium and silver as the reflector materials and higher efficiency (4.182 %) was achieved using a silver dish reflector. Solar PV cooling from 82 °C to 25 °C was investigated and the findings revealed that 439.12 L of H2O and 0.164 kW are required at an operating cost of $0.571. An efficiency of 45.46–75.41 % for the pyrolysis unit, 60 % for the SPDC and 17 % for the solar PV were recorded. This study also recommends the installation of one pyrolysis system in each rural community and equip each rural household with the developed solar systems.

Semi-continuous cultivation of microalgae to treat coal mine effluent in pilot scale: Nutrient removal, biodesalination and fatty acid composition analysis

Coal excavation is associated with discharge of an enormous amount of mine water rich in salt and trace metal ions, which require efficient treatment before use. Considering the potentiality of microalgae for high salt tolerance, salt removal and metallic pollutant removal from aqueous system, present study focuses semi-continuous cultivation of candidate microalgae Chlorella pyrenoidosa (NCIM 2738) in bubble column reactor (BCR) and open raceway pond (ORP) for nutrient supplemented coal mine effluent (NSCME) treatment. In between different hydraulic retention times (HRTs), HRT 6 d provide maximum average biomass productivity of 950 mg L−1 d−1 in BCR and 728.4 mg L−1 d−1 in ORP. HRT 9 d facilitates a maximum lipid content of 1.8 g L ̶ 1 in BCR and 1.4 g L ̶ 1 in ORP. Further, HRT 9 d had the maximum COD removal efficiency (96.5 % in BCR and 94.2 % in ORP) and maximum salinity removal efficiency (93 % in BCR and 92 % in ORP). Fatty acid methyl esters (FAME) characterization highlighted potential biodiesel applicability with cetane number (CN) of 53.94. Energy dispersive X-ray spectroscopy (EDS) revealed an excess amount of salt and metal ions deposition on the surface of harvested microalgae samples. Outdoor large-scale C. pyrenoidosa cultivation can be integrated with coal mine closure plans to meet sustainable development goals (SDGs) 6, 7 and 13.

Pilot scale production of high-content mycoprotein using Rhizopus microsporus var. oligosporus by submerged fermentation and agro-industrial by-products

While mycoprotein has gained traction as a human food source, its potential as a nutrient for animals remains largely unexplored. The mycoprotein-producing Rhizopus microsporus var. oligosporus, a fungus traditionally used for human food in Indonesia, is promising. It could revolutionise animal nutrition once it is Generally Recognized as Safe (GRAS) and is a biosafety level 1 (BSL1) organism. To enhance sustainably, we propose using sugar cane molasses (SM) and corn steep liquor (CSL) as nutrient sources. Also, we investigated the growth of R. microsporus var. oligosporus in five 14 L external-loop airlift bioreactors using CSL as the sole nutrient source. After 96 h of fermentation, at 25 °C and 0.5 vvm, the mycelium produced had an average biomass yield of 38.34 g L−1, with 70.18 % (m v−1) crude protein (mycoprotein). This bioprocess, which is scalable and economically viable, produces high amounts of mycoprotein for animal feed using CSL, a cost-effective agro-industrial by-product, providing a practical solution to the growing demand for animal protein.

Ecological success of no-take marine protected areas: Using population dynamics theory to inform a global meta-analysis.

Adaptively managing marine protected areas (MPAs) requires accurately assessing whether established MPAs are achieving their goals of protecting and conserving biomass, especially for harvested populations. Ecological MPA assessments commonly compare inside of the MPA to a reference point outside of and/or before implementation (i.e., calculating "response ratios"). Yet, MPAs are not simple ecological experiments; by design, protected populations interact with those outside, and population dynamic responses can be nonlinear. This complicates assessment interpretations. Here, we used a two-patch population model to explore how MPA response ratios (outside-inside, before-after, and before-after-control-impact [BACI]) for fished populations behave under different conditions, like whether the population is receiving a sustainable larval supply or if it is declining despite protection from harvest. We then conducted a Bayesian evaluation of MPA effects on fish and invertebrate populations based on data collected from 82 published studies on 264 no-take MPAs worldwide, using the results of an earlier global meta-analysis as priors. We considered the effects of calculating different summary metrics on these results, drawing on the theoretical insights from our population model as a comparative framework. We demonstrate that not all response ratio comparison types provide the same information: For example, outside-inside and BACI comparisons can fail to detect population decline within MPAs, whereas before-after comparisons likely detect that pattern. Considering these limitations, we nonetheless found that MPAs globally are producing positive outcomes, with on average greater biomass, density, and organism size within their boundaries than reference sites. However, only a small portion of studies (18 of 82) provided the temporal data necessary to determine that protection, on average, has led to increased abundance of populations within MPAs over time. These findings demonstrate the importance of considering the underlying system dynamics when assessing MPA effects. Assuming that large outside-inside or BACI response ratios always reflect large and net positive conservation effects may lead to misleading conclusions, we recommend that: (1) when assessing specific MPA effects, empirical findings be considered alongside theoretical knowledge relevant to that MPA system, and (2) management should respond to the local conditions and outcomes, rather than a blanket expectation for positive MPA effects.

Climate factors and food availability shape the altitudinal migration of birds in the Xiling Snow Mountains, China.

Many bird species in montane regions display altitudinal migration, but so far, the underlying ecological driving mechanisms are not clear. We studied the altitudinal migration behavior patterns and factors influencing altitudinal migration in the Xiling Snow Mountains, which are part of the Hengduan mountain range in southwest China. We recorded the local bird diversity, the seasonal change of: the average temperature (AT), the average humidity (AH), the average invertebrate biomass (AIB), and the amount of plant food sources (PFS) at two study sites (∼1300 and ∼2100 m a.s.l.) during two migration seasons from September 2022 to May 2023. During our surveys, we recorded 96 bird species in total. Among these, 15 altitudinal migrants were identified. The most common family among altitudinal migrants was Leiothrichidae. AT, AIB, and PFS had a significant positive correlation with the monthly number of individuals (MNI) several bird species, implying that increasing temperatures and an increasing abundance of invertebrates and PFS possibly induced upward migration of altitudinal migrants and vice versa. AH possibly only played a minor role in influencing altitudinal migration, since it exhibited no significant correlation with the MNI. Furthermore, we found that the upward migration temperature range of altitudinal migrants ranged between 9.8°C and 13.9°C during spring and the downward migration temperature range ranged between 12.2°C and 7.9°C during autumn. In conclusion, our study and several other studies revealed that the same environmental factors influenced the altitudinal migration patterns of birds in the Hengduan Mountains.

Conservation value and carbon sequestration potential of urban green spaces in a growing city: Case of the city of Bouaflé

Faced with the effects of climate change, green spaces are very determining in the provision of ecosystem services, particularly in carbon sequestration. This is why, from a perspective of sustainable management of these high-value spaces, this study was carried out. Surface and itinerant survey methods were combined to collect floristic data. At the end of the inventories, 99 species distributed between 33 families and 75 genera including 24 species with special status were recorded in eight (08) types of development. The total biomass of all the species inventoried at Bouaflé is 4385.78 t, corresponding to a carbon rate of 2192.91 t for a CO2 equivalent of 8047.99 t. The economic value of the rate of CO2 sequestered by all types of development varies from 24143.97 Euros, or 15814274 FCFA according to the CDM carbon price to 112671.86 Euros, or 73800068 FCFA according to the REDD+ carbon price. Social and educational establishments recorded the highest biomass (1841.88 t) while the lowest biomass (5.53 t) was estimated in sports equipment. The average biomass estimated in all types of development is of the order of 232.02±185.64 t/ha, which corresponds to a carbon rate of 116.01±92.82 t/ha and an equivalent CO2 of 425.76±340.65 t/ha. Considering each type of development, the average value of biomass varies between 24.83 t/ha in sports facilities and 468.79 t/ha in cemeteries.

Monitoring seagrass meadows in Maputo Bay using integrated remote sensing techniques and machine learning

Seagrass meadows are one of the most productive and valuable ecosystems on the planet. Monitoring seagrass meadows is essential to understand how these habitats change, and to develop better management and conservation practices. This study integrated satellite imagery from Sentinel-2 and Unmanned Aerial Vehicles (UAV) using machine learning to provide a consistent classification approach for monitoring seagrass in Maputo Bay, southern Mozambique. Sentinel-2 imagery was used to map seagrass extent and changes in Maputo Bay. The UAV systems were used to map seagrass at species level and biomass. All three algorithms tested in the ArcGIS environment could detect seagrass with high producer accuracy and Kappa coefficient. The area of seagrass in Maputo Bay decreased by 33.4 % between 1991 and 2023, with a decreasing trend of 0.48 km2/yr. A zonation pattern was observed for Oceana serrulata and Zostera capensis from the UAV imagery. The small and narrow leaved species (Z. capensis) occurred in the intertidal zone replaced by the broadleaved species (O. serrulata) in the subtidal. The total average aboveground biomass was 33.2 kg dry weight for the mapped area. The results of this study will guide implementation of combined satellite and UAV imagery with machine learning techniques for seagrass monitoring and restoration in Mozambique.

Whether the summer fishing moratorium can improve the status of fisheries resources in the yellow sea and Bohai Sea

The China government has introduced many strategies in fisheries management of the Yellow Sea and the Bohai Sea, the most stringent of which is the summer fishing moratorium. Whether the summer fishing moratorium can restore fishery resources has always been a concern. In this study, we selected eight representative commercial fish species the Yellow Sea and Bohai Sea, including Pampus argenteus, Trichiurus lepturus, Scomberomorus niphonius, Ilisha elongata, Thamnaconus modestus, Scomber japonicus, Engraulis japonicus and Larimichthys polyactis, and used the JABBA method to study their historical exploited dynamics and current stock status. We evaluated the effectiveness of the summer fishing moratorium based on the increments of biomass and catch after its implementation and adjustments. P. argenteus and S. niphonius stocks were in the healthy status in 2022, the other six fisheries stocks were overexploited. The summer fishing moratorium had a strong conservation effect, especially after the first implementation in 1995, with the biomass of six fish species increased and the catch of seven species increased, and the total average biomass and catch increments were 21.22 % and 89.72 %. This positive effect was also reflected after the first adjustment in 2003. Although the moratorium duration was continuously extended after the second and third adjustment, the conservation effect was offset by the flooding of fishing efforts immediately after the moratorium. For the six overexploited stocks, we suggest that the allowable catch of E. japonicus, T. lepturus, L. polyactis, S. japonicus, I. elongata and T. modestus is at most 527.91 kt, 147.51 kt, 93.43 kt, 81.51 kt, 1.25 kt and 4.95 kt in the Yellow Sea and Bohai Sea, respectively.

Influence of Eucalyptus globulus plantations on soil characteristics at different altitudinal levels

This study evaluated the influence of Eucalyptus globulus L. plantations on the physical, chemical and biological properties of the soil in three districts: Magdalena, Tingo and San Isidro del Maino. The evaluation was carried out in six plots, three with eucalyptus and three with natural forests. In each plot with eucalyptus, 10 specimens were selected to measure their dasometric characteristics. Ten soil samples were taken at the base of each specimen to evaluate the bulk density and soil characterization, replicating the sampling in the natural forest plots. Additionally, biological sampling was carried out in each plot using the Rapid Soil Sampling Protocol, with a total of five quadrats per plot. The results showed significant differences in diameter at breast height (DBH), tree height and dry biomass among the districts evaluated. Trees in Magdalena presented the highest DBH and height, with an average biomass of 934.22 kg/tree, while those in Tingo showed the lowest values, with an average biomass of 230.00 kg/tree. Diverse flora species associated with both eucalyptus and natural forests were identified, reflecting a rich biodiversity in each district. Soils with eucalyptus in Tingo showed a predominantly clay texture, while in Magdalena and San Isidro del Maino a sandy loam texture predominated. In the natural forests, the soils in Tingo were also clayey, with more varied textures in the other districts. Bulk density was higher in forest soils in Tingo and in eucalyptus soils in San Isidro del Maino. Soils under eucalyptus had lower pH and lower electrical conductivity compared to natural forest soils. In terms of nutrients, the eucalyptus soils in Tingo and Magdalena showed higher phosphorus and potassium contents, while in San Isidro del Maino, the forest soils had higher levels. In general, eucalyptus soils showed higher levels of organic carbon, organic matter and nitrogen in Tingo and Magdalena, but lower in San Isidro del Maino. Biologically, natural forest soils exhibited a higher diversity and quantity of organisms compared to eucalyptus soils, especially in San Isidro del Maino. Detritivore indices were higher in natural forests, suggesting greater soil biodiversity. This higher diversity could be associated with better soil quality in these systems, highlighting the importance of natural forests in maintaining healthy soils.

Contribution of root and soil properties on soil infiltration capacity of gramineous and leguminous forages during root decomposition

Soil properties are generally altered during root decomposition, which impacts soil water infiltration. Gramineous and leguminous plants present distinct root properties, but it remains unclear whether the root or soil properties are primarily responsible for the soil infiltration capability during root decomposition. To identifythe differences in the contributions of root and soil properties to soil infiltration capability between these two species during root decomposition, a potted plant in situ decomposition experiment was conducted using Bothriochloa. ischaemum (Gramineae) and Lespedeza. davurica (Leguminosae) during three root decomposition times (the 90th, 270th and 450th day). The results revealed that all the root properties (root length, root volume, average root diameter and root biomass) gradually decreased during root decomposition, especially the root length (RL) and root volume (RV) of L. davurica in 0–40 cm soil layer, with reductions of 55.35% and 58.73% at the 450th day compared with the 90th day. The reverse was true for the soil porosity and mean weight diameter of the soil aggregates. Compared to B. ischaemum, L. davurica presented relatively high initial infiltration rate (IIR), steady infiltration rate (SIR), and average infiltration rate (AIR) values at three root decomposition times. A great increase in the soil infiltration rate was observed for both species at the late decomposition stage (450th day), especially for L. davurica, with increases of 38.32%, 267.7%, and 137.1% in IIR, SIR, and AIR. The GLM analysis results revealed that root properties had a greater contribution to the soil infiltration capability. The key factors controlling the soil water infiltration process have been quantified as RL and RV. The present study indicates that leguminous forage presented greater soil infiltration capability during root decomposition. A great decrease in RL and RV within the upper soil layers increased the soil porosity and facilitated the formation of soil aggregates, thereby promoting water flow and ultimately improving the soil infiltration capability.