Mixed Plantations Research Articles

Study on N application and N reduction potential of farmland in China.

The frequent occurrence of extreme weather in recent years poses a significant threat to food production. Ensuring food production and rationalizing the use of agricultural resources require addressing the problem of the improper application of chemical fertilizers. Several effective measures have been implemented in China to reduce agricultural non-point source pollution. Among them, the reduction of excessive nitrogen fertilizer application proves to be the most effective approach in controlling surface pollution from cultivation. Currently, it is crucial to clarify and quantify crop nutrient fertilizer requirements while evaluating the potential for reducing nitrogen fertilizer usage in China. Nitrogen requirements for major crops grown in China were assessed based on the theory of crop nutrient balance, assuming constant grain production as a guarantee. In this paper, we analyze the potential for nitrogen reduction through short-term, medium-term, and long-term scenario predictions. The results show that in the next 3 years, China has a reduction potential of 34.98%, but this potential is not sustainable. Over the next 10 years, there is a reduction potential of 15.04%, with most provinces experiencing a balanced state of soil nitrogen cycling. Hainan, Beijing, Shaanxi, and Fujian have higher reduction potential, with possible reductions of 69.95%, 64.14%, 60.72%, and 54.10%, respectively. However, there are still provinces in China where nitrogen fertilizer is insufficient, leading to soil nitrogen consumption. Specifically, Heilongjiang, Jiangxi, and Shandong Provinces need to increase their nitrogen fertilizer applications by 87.00%, 35.97%, and 8.31%, respectively. The long-term scenario analysis over the next 30 years shows a reduction potential of 40.96%. Among the regions analyzed, Hainan, Beijing, Shaanxi, Fujian, and Ningxia have higher nitrogen fertilizer reduction potentials, with values of 78.97%, 78.48%, 74.25%, 67.87%, and 67.72%, respectively. However, Heilongjiang Province still needs to increase nitrogen fertilizer application by 44.20% to address soil nitrogen depletion. Conversely, Tibet and Qinghai, with high organic fertilizer yields, lower chemical fertilizer usage, and low nitrogen loss coefficients, are well-suited for organic agriculture development. For areas with high organic fertilizers usage and a risk of fertilizer loss, we recommend implementing the organic-inorganic mixed fertilization planting mode.

A system lock-in blocks the uptake of mixed sustainable Eucalyptus plantations in Brazil

Forest plantation areas across the globe are increasing in size and in 2019 Eucalyptus monocultures in Brazil covered 6.97 million hectares (0.8%). These monocultures hardly provide ecosystem services and do not support wildlife habitats. A transition towards more sustainable Eucalyptus plantations is urgently needed to support the provisioning of ecosystem services and conserve biodiversity. This transition requires the development of sustainable business models. We studied the upscaling of sustainable Eucalyptus plantation alternatives in Brazil, by analysing the potential barriers that need to be overcome using the Technological Innovation Systems perspective and semi-structured interviews of relevant stakeholders across the Eucalyptus value chain. Although the provisioning of ecosystem services is improved by alternative plantation management, we identified four blocking mechanisms that inhibit the functioning of the innovation system and as such hamper upscaling; 1) the productivist approach by incumbent actors on plantation management that is focussing only on short-term profit maximisation and results in a strong resistance to change current practices, 2) the weak societal and governmental vision that does not put sufficient pressure to change practices, 3) additional certification to support alternatives is in its infacy to develop niche markets which also hampers the development of financial support, and 4) failed demonstration projects in the past that have led to a lack of proof of concept for further experimentation and knowledge development. These barriers combined lead to a system lock-in, resistant to change and not capable for a diffusion of sustainable alternatives. We conclude that the directionality of a sustainability transformation should be enhanced by formulating long-term goals and strong commitment of public and private actors. We discuss how a mission oriented approach could foster such directionality for the urgently needed regime transformation in Eucalyptus paper and pulp production.

P24-36: Risk assessment of combined exposure to mixed plant protection products on the persons involved in their application in the conditions of modern agricultural production

P24-36: Risk assessment of combined exposure to mixed plant protection products on the persons involved in their application in the conditions of modern agricultural production

Evaluation of fermented soybean meal by Bacillus subtilis as an alternative to fishmeal on the growth, and physiological status of Nile tilapia Oreochromis niloticus fingerlings

A feeding trial was conducted to investigate the effect of fermented soybean meal with Bacillus subtilis bacteria on growth performance, feed utilization, carcass composition, and hematological, and histological section of the liver and intestine of Nile tilapia Oreochromis niloticus fingerlings. Commercial soybean meal (SBM) containing 44% Crude Protein (CP) was fermented using the solid-state fermentation method which depended on autoclaving of SBM, then bacterial treatment injection by Bacillus subtilis, and finally incubation at 40C for 72 h then autoclaved to stop the growth of bacteria. Five isonitrogenous (25% crude protein) and isocaloric (4.4 kcal\\g gross energy) experimental fish meal-free diets were formulated to compare with a common control diet containing fishmeal and unfermented soybean meal. Diets without fish meal contain fermented soybean meal (FSM) as a sole protein, FSM with corn gluten (CG), FSM with free amino acid methionine (Meth), FSM with corn gluten and methionine, and unfermented soybean meal. Eighteen glass aquaria, 80-L net volume, were used to stock 10 fingerlings (10.0 ± 0.1 g/fish) in each aquarium in the replicates group. The feed amount was given three times daily, six days a week throughout the 98 days experimental period. Fish were weighed biweekly and feed amounts were adjusted based on the new fish weight. Bacterial fermentation enhanced the protein content of commercial soybean meals by 6%. The crude protein of fermented soybean meal increased from 43.44% to 50.67%. Used of FSM as a sole dietary protein source resulted in a decrease in growth rate and feed utilization. However, the incorporation of FSM with corn gluten, and/or methionine amino acid led to an improvement in the performance of fish. Finally, the best final body weight, weight gain, specific growth rate, protein efficiency ratio, and protein productive value were recorded by a fish-fed mixed plant protein diet (FSM + CG + Meth). Also, Hematocrit and red blood cells were not significantly affected including the FSM.

REVIEW OF ENVIRONMENTAL DAMAGE DUE TO ILLEGAL COAL MINING IN BUKIT SOEHARTO FOREST PARK IN EAST KALIMANTAN PROVINCE

Illegal coal mining activities cause environmental problems, especially in Bukit Soeharto Forest Park. The purpose of this study was to know the actual conditions land cover and environmental damage in Bukit Soeharto Forest Park for the 2015-2020 period. The research method will be analysed from mining land cover class (cover code 20141) using satellite citra and overlaying using ArcView and GIS computer program. The following conclusions can be drawn from the findings of the data file that area has been partially used incompatible with the function of the Forest Park area. The area that is still a compliant function of the Forest Park is 67.62% of the total area, which consists of secondary dry land forest, shrubs, secondary mangrove forest, swamp scrub, plantation forest and body water. The area of land use inconsistent with regional functions is 32.38% of the total area, where this area is used for mining, mixed dry land agriculture, plantations, open ground, settlements, and ponds. Therefore, it is necessary to establish a task force to save the Bukit Soeharto Forest from various threats of damage to the area.

Reproductive systems and hybridization of Lymania species (Bromeliaceae) endemic to Northeast Brazil threatened with extinction

Reproductive systems among the Bromeliaceae family are very diverse at the species level, including allogamous, autogamous, cleistogamous, agamospermic or mixed plants. Hybridization allows the creation of new genotypes with different combinations of shapes and colors to meet the ornamental plant market's demand for novelty. Knowing the reproductive strategies of the species makes it possible to obtain these new materials with ornamental potential, in addition to being essential to define better conservation strategies. Little is known about the reproductive biology of Lymania species. In addition, at least 60% of these species are on the Brazilian National List of Species Threatened with Extinction. The purpose of this study was to identify the reproductive systems, the possible interspecific hybridizations, and the possible reproductive barriers of nine Lymania species based on the germination of pollen grains and the corresponding growth of the pollen tube in the pistil by using fluorescence microscopy with ultraviolet filtering. Natural and controlled pollinations of the nine species were carried out. The reproductive strategy was defined according to the autogamy index (AI), self-incompatibility index (SII), and reproductive efficiency index (REI). All species were self-incompatible except for L. smithii, which was autogamous. Agamospermy was not observed in any of the studied species. Forty-one hybridization combinations between species were performed, resulting in a 54% success rate, with incongruity in only 12 combinations. The main incongruence phenomena identified after interspecific crosses were: poor germination of pollen grains on the stigma surface; inhibition of pollen tube growth along the style; coiling of pollen tubes along the style; pollen tubes inside the ovary but without penetration into the micropyle; and reticulate deposition of callose in the pollen tube, among others. We suggest that self-incompatibility of the species is gametophytic, preventing self-fertilization. Results showed that it is possible to perform hybridization with some species. However, morphological, genetic, and molecular studies are needed to confirm the potential of these species. Seeds generated in the different reproductive systems, as well as in the hybridizations, had germination rates above 94%. The results presented here make important contributions to the conservation of species, seed generation, and hybridization of Bromeliaceae.

ON THE COMPARATIVE ANALYSIS OF THE COMPOSITION OF LYSIMETRIC WATER UNDER CONDITIONS OF DIFFERENT SOIL TREATMENT AND UNDER PHYTOCENOSES

A comparative analysis of the composition of lysimetric waters for 2021–2022 was carried out. for two groups of stationary soil lysimeters in the city. The first group of lysimeters is formed by the system: fallow — grass phytocenosis — overgrown fallow — spruce forest — mixed and broadleaved plantation, developing on the same type of mantle loam. The second group of lysimeters represents soils with different types of tillage: conventional plowing, extradeep planting according to Bushinsky, plowing according to Mosolov, deep plowing according to Kachinsky.For both groups, the same type of migration of components is shown, in which the most migrating elements are carbon, mono- and divalent cations, and chloride ion, with minimal migration of iron, manganese, and aluminum.In the group of lysimeters under various types of vegetation, as the tree canopy develops and, accordingly, the intensity of the biological cycle increases in migrating waters, the concentration of such important biophilic elements as magnesium, calcium, potassium, and carbon increases significantly, and among anions, chloride and sulfate ions. This determines, within the framework of the cluster analysis, two different subgroups in terms of the composition of natural waters: the first one is formed by the fallow-grass phytocenosis — overgrown fallow system, and the second one combines tree plantations.In the group of lysimeters with different tillage, a cluster characterizes the composition of water in lysimeters with reclamation plowing according to Mosolov and deep plowing according to Kachinsky. At the same time, individual aggregates form lysimeters with conventional plowing and ultradeep planting according to Bushinsky. This is explained by the fact that in this group of lysimeters, the initially created soil profile design is transformed, which is characterized by the placement of eluvial and illuvial soil horizons in various combinations and at different depths depending on the type of plowing.

Phytochemical Screening on Phenolic, Flavonoid Contents, and Antioxidant Activities of Six Indigenous Plants Used in Traditional Thai Medicine.

The antioxidant activity of a traditional Thai formula has been studied and compared to each plant. The formula comprised the roots of Caesalpinia digyna Rottler, Huberantha cerasoides (Roxb.) Benth), Oxyceros horridus Lour, Antidesma ghaesembilla Gaerth, Combretum quadrangulare Kurz, and Ziziphus cambodiana Pierre. The stem was also studied in comparison. The ethanolic extract from each plant part and the mixed plants mimicking the traditional formula were prepared and investigated for antioxidant capability in vitro via DPPH radical scavenging and ferric-reducing antioxidant power assays. The phytochemical constituents were determined by chemical screening, total phenolic (TPC) and flavonoid contents (TFC), and high-performance liquid chromatography. The relationship between antioxidant activity and the contributed phytochemicals was determined using correlation analysis and principal component analysis (PCA). Results showed that extracts from both parts of the plant formula showed the highest antioxidant activity compared to a single plant extract. Among the six plants, C. digyna exhibited the highest TPC and antioxidant activity. TPC had a strong positive correlation with antioxidant activity. PCA revealed that gallic acid contributed to the antioxidant activity. In conclusion, the ethanolic extracts of the traditional formula and C. digyna have the potential for further chemical characterization and study related to antioxidant activity.

Experimental Study on the Permeability of Ecological Slopes under Rainfall Infiltration Conditions

This paper investigates the influence of different vegetation on the permeability of the shallow soil layers of slopes under rainfall infiltration. Firstly, four large slopes are filled in an outdoor natural environment, and the overburdens of the four slopes are Magnolia multiflora, Cynodon dactylon, Magnolia multiflora mixed with Cynodon dactylon, and no vegetation. Secondly, the four slopes are cultivated in an outdoor natural environment for one year. After the vegetation overburdens are matured, the field artificial rainfall test is carried out through a self-developed artificial rainfall device to monitor the water migration law inside the four slopes in real time. Finally, the unsaturated permeability coefficients of the shallow soil layers of slopes are calculated. The results show that the infiltration rate of rainwater in each overburden slope from fastest to slowest is Magnolia multiflora overburden slope, no vegetation slope, Cynodon dactylon overburden slope, and Magnolia multiflora mixed with Cynodon dactylon overburden slope. In the early stage of rainfall, Magnolia multiflora increases the permeability coefficient of the shallow soil layer of the slope, thus weakening the anti-seepage ability of the slope, but the influence of Magnolia multiflora is not obvious in the later stage. Cynodon dactylon and Magnolia multiflora mixed with Cynodon dactylon can significantly reduce the permeability coefficient of the shallow soil layers of the slopes, thereby increasing the anti-seepage ability of the slopes, and the mixed planting of Magnolia multiflora and Cynodon dactylon can minimize the permeability coefficient of the shallow soil of the slope, resulting in the best anti-seepage effect.

Soil extracellular enzyme stoichiometry reveals the increased P limitation of microbial metabolism after the mixed cultivation of Korean pine and Manchurian walnut in Northeast China

Korean pine (Pinus koraiensis) and Manchurian walnut (Juglans mandshurica) are the main tree species used for plantation regeneration in Northeast China, and their mixed cultivation is typically used to address a decline in stand productivity in long-term monocultures. However, little is known about the changes in the C, N and P requirements of soil microbial metabolism between monocultures and mixed plantations. In this study, we examined the effect of plantation type on the soil microbial metabolic limitations by investigating the soil extracellular enzyme activities across three plantation types (P. koraiensis monocultures, J. mandshurica monocultures, P. koraiensis and J. mandshurica mixed plantations) of the same age (32 years old). We used ecoenzymatic stoichiometry methods to reveal the patterns of microbial metabolic C, N and P limitations along a soil depth gradient of 0–10, 10–20, and 20–40 cm by collecting a total of 81 composite soil samples including three plantation types. With the increased soil depth, the activities of C-, N- and P-acquiring enzymes in mixed plantations decreased from 93.60 nmol g−1 soil h−1 to 20.52 nmol g−1 soil h−1, 33.46 nmol g−1 soil h−1 to 22.09 nmol g−1 soil h−1, and 11.80 nmol g−1 soil h−1 to 7.30 nmol g−1 soil h−1, respectively. Enzymatic vector analysis (vector angle >45°) revealed P limitation rather than N limitation of microbial metabolism across all plantation types. Of the plantations, the mixed stands had the greatest vector length (1.15 ± 0.02) and vector angle (56.91 ± 1.47). The interactions of plantation type and soil depth had significant effects on microbial metabolic C and P requirements. Changes in soil available nutrient contents and stoichiometry ratios of C, N and P across different plantation types were the two most important soil variables affecting microbial metabolic C and P requirements.

Litter stock, litterfall and nutrients in the Amazonia: defining patterns from last 40 years of scientific research

Nutrient cycling, guaranteed by the decomposition of litter, stands out as an essential process for maintaining Amazonian ecosystems. Studies on the litter layer on the soil surface are indispensable, primarily because they help provide information about functional and structural aspects of the ecosystem. Therefore, to define parameters related to the storage and production of litter and nutrients in Amazonia, we conducted a qualitative and quantitative analysis of articles in academic publications developed in Amazonia in the last 40 years (1980- 2019). We identified 83 articles, with the majority (85.39%) developed in Brazil. We found that 67% of these studies were related to the litterfall method and only 11.24% were related to both collection methods (litter stock and litterfall). The litter stock ranged from 4.94 ± 2.07 Mg ha-1 to 11.05 ± 4.67 Mg ha-1 for Agroforestry Systems (AFS) and Mixed Plantation (MIP), respectively. While litterfall ranged from 2.09 ± 1.14 Mg ha-1 year-1 to 9.01 ± 6.09 Mg ha-1 year-1 for pasture ecosystems (PAS) and AFS. The litter nutrients in Amazonia follow the following decreasing order: N>Ca>K>Mg>P. Our results indicate the need for more attention and investment in Amazonian forest research, so that more studies on the subject may be developed, especially those focusing on ecological restoration.

Environmental factors induced crop raiding by wild Asian elephant (Elephas maximus) in the Eastern Economic Corridor, Thailand

Crop raiding are an increasing concern in wildlife conservation. This study identified the environmental factors that cause wild Asian elephants (Elephas maximus) to enter sub-urban and rural areas and share resources with humans in the Eastern Economic Corridor (EEC) in the eastern part of Thailand. The snowball method was used to interview villagers that had crop raiding experienced in seven provinces of the EEC and adjacent provinces in the eastern part of Thailand in 2020, and data from 183 households indicated that crop raiding had increased continuously from 2000 to 2020, especially in Chonburi, Chachoengsao, and Prachinburi provinces, which have seen increases in damaged agricultural areas. MaxEnt analysis showed an increase in incidents of crop raiding, while the elephants distribution area decreased from 9534 km2 in 2000 to 5199 km2 in 2010 and 4850 km2 in 2020. The study area has had land use changes in the low elevations from croplands of cassava and sugar cane to eucalyptus, para rubber, and fruits. These mixed crop plantations provide a pseudo-habitat for wild Asian elephants. The results from this study provide evidence that changes in land use and reduction of suitable habitat are factors that influenced the movement of wild Asian elephants to the rural agricultural areas and increased the incidents of crop raiding.

Tree species mixing begets admixture of soil microbial communities: Variations along bulk soil, rhizosphere soil and root tissue

Tree species can substantially impact the structure and functioning of soil microbial communities. However, how tree species mixing affects soil microbial communities along different soil compartment niches remains unknown, despite the theoretical (e.g., plant-soil feedback) and practical (e.g., rhizosphere engineering) importance of such knowledge in understanding and managing forest ecosystems. In this study, we analyzed soil samples taken from three microhabitats (bulk soil, rhizosphere soil, and root tissue) of pure conifer species (Pinus massoniana) plantations (PP), pure broadleaf species (Castanopsis hystrix) plantations (PC), and mixed plantation forest of the two species (MF) to understand the effects of tree species mixing on core soil microbial communities. We found that the diversity of soil bacterial and fungal communities was not affected by tree species mixing in most cases, but community composition (relative abundance and functional composition) was largely shaped by tree species mixing. Non-metric multidimensional scaling (NMDS) analysis revealed that the core bacterial and fungal communities of MF were between those of PP and PC. This suggests that tree species mixing can lead to a combination of soil microbial communities associated with each of the two tree species, potentially resulting in higher nutrient contents in the bulk soil of MF and lower phosphorus and carbon limitations in both the bulk and rhizosphere soils of MF compared to those of PP and PC. The Mantel test and redundancy analysis (RDA) showed that pH and NO3–-N content were the main environmental variables influencing soil microbial communities. Overall, the effects of tree species mixing varied markedly with microhabitat and season, with rhizosphere soil having the highest microbial diversity and network complexity and root tissue having the lowest. These results suggest that the mixing effects of tree species are more pronounced in the rhizosphere and dry season, on which silvicultural practices should focus.

The Effects of Korean Pine and Manchurian Walnut Monocultures and Mixed Plantations on Soil Fungal and Bacterial Communities

(1) Background: Korean pine (Pinus koraiensis) and Manchurian walnut (Juglans mandshurica) are the main tree species for plantation regeneration in Northeast China, and the mixed plantation of them is one of the typical measures adopted to address the decline in stand productivity in long-term monocultures. However, little is known about the effects of Korean pine and Manchurian walnut monocultures and mixed plantations on soil microbial diversity, composition, and functional groups. (2) Methods: We used ITS and 16S rRNA gene sequencing to detect fungal and bacterial communities and used the FUNGuild, FAPROTAX, and Bugbase databases to predict their functional groups. (3) Results: Fungal and bacterial alpha diversity were always higher in Manchurian walnut monocultures than in Korean pine monocultures. The plantation type had a greater impact on the fungal composition than the bacterial composition. The fungal functional groups were significantly affected by the plantation type (p < 0.05), while the bacterial functional groups were barely changed among all plantation types. The soil available nutrient content was the most important soil factor in shaping the microbial community structures and functional groups. (4) Conclusions: Shifts in fungal community compositions and functional groups might play a dominant role in soil nutrient cycling across the different plantation types in Northeast China.

The water balance analysis of several land uses in Tinalah sub-watershed, Kulon Progo

Tinalah sub-watershed has vulnerable to the threat of erosion and landslides. Erosion in the upstream watershed can trigger catastrophic flooding in the area below it. In addition, the problems that occur every year in the Tinalah sub-watershed are drought during the dry season and flooding during the rainy season. The water balance was analyzed by using Thornthwaite and Matter. The result shows that the dry index increased from June and the highest is in August. The highest runoff is in June (0.93). Mostly the land uses have deficit water during 4 months that are June to September, except the mixed planting has 3 months of deficit, whereas the area of the settlement has a longer deficit until 5 months. The simulation of land use in an agroforestry system shows the decreasing value of the deficit which then it will affect the value of the Drought Index (Ia) which also decreases.

Development of an automated control and management system for a fertilizer mixing plant

Relevance. The use of complex multicomponent fertilizers in some cases is unjustified economically and can often lead to soil degradation. In such cases, in order to ensure the plantʼs need for the necessary nutrients, it is advisable to use fertilizer mixtures with a given number of components. Thus, in order to comply with the exact proportions of the components of the created fertilizer mixture, the task of creating an automation system becomes urgent, which includes not only a machine for mixing with a high coefficient of unevenness of the resulting fertilizer mixture, but also a software package for determining the component composition of the fertilizer mixture depending on the conditions of the economy, as well as an automated system of weight control and control of metering dampers working together.Methods. The technologies of production of flour mixtures are considered, the main types of mixing used in their creation are determined. To implement the project on automating the processes of flour mixing at the developed technological installation, the methods of analytical, comparative, information and logical analysis of the initial information were used.Results. А system of automated control of the technological process of fertilizer mixture was obtained at the developed fertilizer mixture plant, which allows using the joint work of all components in it to calculate the necessary composition and formulation of the fertilizer mixture, to obtain high-quality fertilizer mixtures due to accurate dosing of components and their biological modification.

Responses of Selected Soil Properties to Mixed Tree Plantation and Cassava Land Use in Southern Nigeria

Responses of some selected soil properties to mixed tree plantation and cassava land use in southernNigeria were evaluated in this study. The objectives were to examine variations in the selected soilproperties among the different agricultural land use types; ascertain relationships between the soilproperties; and evaluate cause-effect relationships between the soil properties. A total of 54 soil samplesat 0-15 and 15-30 cm depths were collected from mixed tree plantation, cassava land use and secondaryforest using transect sampling method. Soil samples were analysed for selected physical, chemical andbiological properties following standard laboratory methods. The results revealed significant variations(p ≤ 0.05) in the values of sand, silt, bulk density (BD), total porosity (TP), pH, total heterotrophic bacteriacounts (THB) and total heterotrophic fungi counts (THF) in soils of the three land use types. The valuesof BD and TP did not exceed the respective critical limits of 1.75 g cm-3 and 40% for productive soils.However, pH, available phosphorous (Avail. P), soil organic carbon (SOC), soil organic matter (SOM),THB and THF responded negatively to mixed tree and cassava cultivation in the 0-15 cm soil depth astheir values were lower than that of the control site. Significant positive (e.g., silt versusSOM/SOC/TN/Avail. P, and TP versus pH) and negative (e.g., clay versus SOC/SOM/Avail. P)relationships as well as significant cause and effect relationships (such as Avail. P versussilt/clay/TP/SOC/SOM/TN) were observed between some of the soil properties across the three land usetypes and soil depths. The study concluded that the examined soil quality indicators responded differentlyto the evaluated land use types.

Mosses stimulate soil carbon and nitrogen accumulation during vegetation restoration in a humid subtropical area

Mosses form a ground layer with a thickness of nearly 1 cm during the first decade of vegetation restoration, but their effects on the belowground microbial community and soil properties and the associated soil carbon (C) and nitrogen (N) accumulation in subtropical areas are unclear. Here, we measured soil C and N variables (soil organic C [SOC], total N [TN], dissolved organic C, ammonium [NH4+-N] and nitrate [NO3−-N]), soil microbial community and soil properties (soil water content [SWC] and pH) under four treatments (bare soil [BS], bare soil with transplanted moss, moss-covered soil [MS] and moss-covered soil with moss removed) in three vegetation types (forest plantations, forage grasslands and mixed plantations and forage grasslands) in a subtropical climate. We analyzed the effects of native mosses, moss transplantation and removal using BS and MS as references. One year post-treatment, moss transplantation increased NO3−-N and NH4+-N in the 0–5 cm and 2–5 cm soil layers, respectively. Conversely, moss removal decreased SOC and TN in the 0–2 cm soil layer and SWC in the 0–5 cm soil layer. Compared to BS and MS, native moss presence, moss transplantation and removal decreased the total microbial, bacterial and fungal biomass and altered the soil microbial community composition (ratios of fungi and bacteria and Gram-positive bacteria to Gram-negative bacteria) to varying degrees. Moss properties (biomass, C and N concentrations, C:N ratio and saturated water absorption content), as well as SWC, soil microbial biomass and community composition regulated by mosses affected soil C and N. These findings underscore the crucial role of mosses in facilitating soil C and N accumulation during vegetation restoration.

From Sphagnum to shrub: Increased acidity reduces peat bacterial diversity and keystone microbial taxa imply peatland degradation

AbstractPeatlands store one‐third of the Earth's carbon. Human activities and climate change‐induced peatland vegetation shift from Sphagnum to shrub may lead to peatland degradation. To understand the ecology and functions of these peatlands, we collected samples from 10 peatland mosaics dominated by Sphagnums, mixed plant communities of Sphagnums, and shrubs across south China. Through sequencing the plant rhizosphere microbiome and measuring peat properties, we explored the plant–soil interactions and identified the keystone microbial taxa in peatlands of three vegetation types. Results showed that peat pH decreased along with the plant community shift from Sphagnum to shrub, which may be due to the accumulation of sulfur and phenolics. Lower pH further reduced bacterial diversity in shrub peatlands as Acidobacteriota became predominant in the keystone taxa. Overall, microbiomes in shrub peatlands showed degraded properties, such as a less stable microbial community dominated by few keystone taxa and the loss of methane‐mitigating microbes. The keystone microbial taxa in Sphagnum peatlands included microbes that utilize insoluble organic substances, mono‐ and oligo‐saccharides. Most importantly, the methanotrophic microbes that oxidize methane only appeared in the keystone taxa of Sphagnum peatlands. Mixed plant community peatlands contained the highest concentrations of iron. Slow‐growing fungi and bacteria were in the keystone microbial taxa, indicating slow decomposition rates in these peatlands. Our study suggests that human activity and climate change‐induced peatland vegetation shift from Sphagnum to shrub leads to an unstable belowground community, indicating the degraded peatland, which may exacerbate in the future.

Arbuscular mycorrhizal inoculation alleviates water competition between adjacent plants in the mixed planting system

Exploring the water use strategies of different plant species is very important in understanding the mechanisms of soil-plant interactions in water-limited ecosystems. There is limited information on changes in plant water use in mixtures of species, and little is known of the role of arbuscular mycorrhizal fungi in regulating the water use strategies of host plants in mixtures. The water use strategies of three plant communities in arid and semi-arid mining areas were investigated. These were Medicago sativa (alfalfa) in monoculture (A), Caragana korshinskii (Korshinsk pea shrub) in monoculture (C), and Medicago sativa + Caragana korshinskii in mixture (MIX). Each plant community was inoculated with an arbuscular mycorrhizal fungus or uninoculated to determine the regulation of plant water use strategy by the fungus. There was a significant difference in the use of soil water by both plant species in mixture compared with monoculture (P < 0.05). In the mixture there was significant competition for water between depths 0–40 cm and 40–100 cm. Both species took up more water from the surface soil than in monoculture. Mycorrhizal inoculation reduced the dependence of the plants on surface soil water, effectively alleviated the competition for water between the two plant species in mixture. The results indicate that the impact of arbuscular mycorrhizal fungi on the water use strategies of different plant species in mixtures should be considered when ecological restoration of vegetation is carried out in arid and semi-arid areas.