Long-term monoculture of Chinese fir plantations leads to soil degradation and declining forest productivity, prompting forest managers to seek alternative tree species for forest regeneration. Oaks (Fagaceae) produce high-quality large-diameter timber and support the long-term stability of their forest ecosystems. However, the response patterns of soil bacterial communities following the conversion from Chinese fir to pure oak plantations remain poorly understood. At Kaihua Forest Farm, we investigated the differences in soil bacterial community composition, diversity, assembly processes, co-occurrence networks, and potential functions among a 20-year-old Chinese fir plantation and four 5-year-old oak plantations. The results showed that converting Chinese fir to oak plantations increased soil available phosphorus and potassium contents and modified soil bacterial community composition and structure, while Acidobacteria remained dominant. The establishment of QG and QF increased the Chao1 and Shannon indices of the bacterial community. Stochastic processes governed assembly, with QF enhancing niche breadth and stochasticity. Co-occurrence networks were consistently dominated by positive correlations, and among the four oak plantations, QF exhibited the highest complexity and stability. FAPROTAX prediction revealed changes in potential functions: fermentation and iron reduction were enriched in QF, nitrogen-fixing functional groups were enriched in QG, and carbon cycling and organic pollutant degradation were enriched in CH. Overall, this study revealed variations in soil bacterial communities among different forest stands and enhanced our understanding of how forest conversion affects soil bacteria. When converting Chinese fir plantations, alternative tree species should be selected based on local site conditions and management objectives.

Soil organic carbon (SOC) represents the largest terrestrial carbon (C) pool, and even small changes in its stock can exert great influences on regional and global C cycles. Quantifying the spatial distribution of forest SOC and identifying its key drivers are therefore central to climate change science. In this study, we collected 150 topsoil samples (0–20 cm) across six vegetation types spanning an elevation gradient of 500–1,900 m in Baishanzu National Park, Zhejiang Province. Soil organic carbon density (SOCD) was determined alongside litter stock, and the activities of three cellulolytic hydrolases—α-glucosidase (AG), β-glucosidase (BG), and cellobiohydrolase (CBH). Ten environmental covariates derived from remote sensing, climate, and topographic data were used to predict SOCD. Three machine learning models—random forest (RF), boosted regression trees (BRT), and eXtreme Gradient Boosting (XGBoost)—were evaluated using repeated nested five-fold cross-validation and nested nearest neighbor distance matching cross-validation (NNDM-CV), with hyperparameter tuning restricted to the corresponding outer-training partitions. The three algorithms showed broadly comparable predictive performance across the two validation schemes. Based on the XGBoost model, the predicted mean surface SOCD across the park was 108.6 t C hm −2 , with pixel-level values ranging from 39.4 to 160.6 t C hm −2 . The total surface SOC stock was approximately 5. 4 × 10 6 t C. The bootstrap ensemble indicated moderate resampling-based model uncertainty, with a mean pixel-level standard deviation of 10.0 t C hm −2 and a mean coefficient of variation of 9.5%. SHAP analysis showed that vegetation-related variables dominated SOCD prediction. Structural equation modelling showed that the vegetation index had both a positive direct effect on SOCD and an indirect positive effect mediated by litter stock, whereas the C-acquiring enzyme index was negatively associated with SOCD. These findings improve our understanding of the spatial distribution of SOCD in subtropical montane forests and provide a scientific basis for regional C stock assessment and forest ecosystem management.

Forest mushroom systems (FMS), as a sustainable agroforestry practice, may play a critical role in soil carbon sequestration and fungal community dynamics. However, their long-term impacts on soil organic carbon (SOC) fractions and fungal community reassembly remain poorly understood. This study investigated the effects of three mushroom species (Dictyophora indusiata, Morchella esculenta, and Stropharia rugosoannulata) cultivated under intensively managed Moso bamboo forests on soil carbon fractions and fungal communities over three years. Soil chemical properties, carbon fractions (particulate organic carbon, POC; mineral-associated organic carbon, MAOC), and fungal community composition were analyzed. Across all the treatments, MAOC and SOC generally exhibited a significant increase over the first two years, followed by a slight decrease in the third year, while POC showed no significant variation among years. Compared with TM, DI treatment led to a decrease in soil carbon fractions, while SR treatment resulted in an increase. ME treatment witnessed a decline in MAOC and SOC, but an upsurge in POC. Fungal community alpha-diversity initially increased (ME and SR) but slightly declined over time, with shifts in dominant phyla (Ascomycota, Basidiomycota) linked to organic matter input and environmental adaptation. Network analysis highlighted increased fungal community stability in later years, correlating with SOC retention. Partial Least Squares Path Modeling identified fungal community stability and soil chemical properties as key contributions of carbon fractiocontributions of different factorsn dynamics. This study underscores the ecological role of FMS in modulating soil carbon sequestration through fungal community restructuring, offering insights for sustainable forest management and climate-smart agroforestry practices.

Intensive nitrogen (N) fertilization in Phyllostachys edulis (Carri & egrave;re) J.Houz. forests increases productivity but also accelerates nitrous oxide (N2O) emissions, posing a challenge to balancing forest yield with environmental sustainability. Silicon (Si), a beneficial element for bamboo, has emerged as a potential regulator of soil nitrogen (N) cycling, but its role in controlling N2O emissions in forest ecosystems is not fully understood. In this study, we conducted a factorial pot experiment using P. edulis forest soil, with data collected over two years, but only the second-year results were analyzed, with controlled N (0, 80, and 160 mg kg(-1)) and Si (0, 25, and 50 mg kg(-1)) additions. The experiment lasted two years, but only the second-year data were used for analysis. We investigated how Si affected soil inorganic N dynamics, enzyme activities, plant growth, and cumulative N2O emissions. Si addition significantly reduced N-induced N2O emissions by up to 53%, with the strongest mitigation observed under moderate N input (p < 0.05, two-way ANOVA). This effect was associated with lower activities of AMO, NaR, and NiR, together with reduced availability of oxidized N substrates, indicating that Si mitigated N2O emissions mainly by constraining upstream N transformation processes rather than by directly suppressing N2O fluxes. Si addition also tended to promote plant biomass accumulation. These findings suggest that integrating Si fertilization into bamboo forest management may help improve nutrient use efficiency while mitigating greenhouse gas emissions.

Mineral-associated organic carbon (MAOC) is a persistent fraction of soil organic carbon (SOC) that is central to long-term carbon (C) persistence and climate mitigation. Along an elevation gradient, soil texture and chemistry vary with climate and coincide with shifts in microbial communities, but it remains unclear whether MAOC aligns more strongly with abiotic soil attributes or biotic microbial necromass, and whether these relationships change from across-gradient patterns to within-elevation variation. In this study, we investigated SOC fractions in a subtropical mountain system and examined the factors associated with MAOC variation across the elevation gradient and within elevation bands. Across the elevation gradient, MAOC variation was best explained by elevation-associated changes in soil mineral properties, including amorphous Fe oxide, clay + silt content and pH. In contrast, within individual elevation bands, MAOC was positively correlated with total microbial necromass carbon (TNC). In addition, fungal necromass carbon (FNC) explained more variation in MAOC than bacterial necromass carbon (BNC); and TNC was significantly correlated with fungal community composition within bands. Notably, the relationship between TNC and MAOC weakened with increasing elevation. Taken together, our results indicate that MAOC patterns along the elevation gradient are primarily linked to mineral preservation, whereas within-band variation in MAOC is more closely related to bulk-soil microbial necromass C. These findings may help to reconcile conflicting views on MAOC regulation and highlight the context-dependency of soil C stabilization.

Coptis chinensis var. brevisepala W. T. Wang & P. G. Xiao is an endemic and endangered medicinal plant in China whose wild populations are rapidly declining under the combined pressures of overharvesting, climate change, and habitat fragmentation. Using genotyping-by-sequencing, we analyzed 87 individuals from 15 populations in Zhejiang Province, China, and identified 155,611 high-quality SNPs. The species exhibited low genetic diversity and strong genetic differentiation among populations with restricted gene flow (population-averaged Ho = 0.066, He = 0.067, π = 0.078, FIS = 0.029, FST = 0.503, Nm = 0.329, gRelMig = 0.136). Analysis of molecular variance showed that variation among populations accounted for 73.58% of the total genetic variation (p < 0.001). A phylogenetic tree, principal component analysis (PCA), and admixture analysis consistently resolved the 15 populations into two major groups, which could be further subdivided into four subgroups. Mantel and partial Mantel tests indicated that geographic isolation is the primary driver of genetic differentiation, while environmental factors such as ultraviolet radiation and low temperature may contribute to fine-scale divergence at local spatial scales. Furthermore, MMRR analysis provided further confirmation of the independent and dominant role of geographic isolation. This study provides key data on the genetic diversity and population structure of C. chinensis var. brevisepala and offers a genetic basis for developing regionally differentiated conservation strategies and promoting its sustainable utilization.

Long-term monoculture of Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook) plantations leads to soil degradation and declining productivity, prompting forest managers to seek alternative tree species for forest regeneration. Oaks (Fagaceae) produce high-quality large-diameter timber and support the long-term stability of their forest ecosystems. However, the response patterns of soil bacterial communities following the conversion from Chinese fir to oak plantations remain poorly understood. At Kaihua Forest Farm, we investigated the differences in soil bacterial community composition, diversity, assembly processes, co-occurrence networks, and potential functions among a 20-year-old Chinese fir plantation (CL) and four 5-year-old oak plantations ( Quercus glauca Thunb (QG), Castanopsis fargesii Franch (CF), Castanea henryi (Skan) Rehder & E. H. Wilson (CH), and Quercus fabri Hance (QF)). The results showed that converting Chinese fir to oak plantations increased soil available phosphorus and potassium contents and modified soil bacterial community composition and structure, while Acidobacteria remained dominant. The establishment of QG and QF increased the Chao1 and Shannon indices of the bacterial community. Stochastic processes governed assembly, with QF enhancing niche breadth and stochasticity. Co-occurrence networks were consistently dominated by positive correlations, and among the four oak plantations, QF exhibited the highest complexity and stability. FAPROTAX prediction revealed changes in potential functions: fermentation and iron reduction were enriched in QF, nitrogen-fixing functional groups were enriched in QG, and carbon cycling and organic pollutant degradation were enriched in CH. In summary, conversion from CL to QF confers greater benefits to soil bacterial communities, and QF can be selected as an alternative tree species for converting subtropical Chinese fir plantations.

Successive cropping frequently causes a decline in Chinese Fir (Cunninghamia lanceolata) biomass, a problem intricately tied to soil nutrient shifts and microbial processes. This research investigates the mechanisms governing biomass carbon partitioning and soil nutrient shifts in these plantations. This study investigated five Chinese Fir clones ('ck', 'b44', 'K13', 'F13', and 'kt13') across two cultivation regimes: continuous cropping (second-generation plantation, G2) and first-generation plantation (G1). The focus was on their biomass and soil nutrient status. The results showed that: (1) The biomass of different Chinese Fir clones at 25 years of age decreased significantly with increasing generations of continuous cultivation. Tree height showed no significant differences among clones within the same generation; however, the G2 cultivation significantly inhibited diameter at breast height (DBH). (2) The changes in soil nutrients and microbial activity under different successive generations (G1, G2) was closely linked to the decline in Chinese Fir biomass carbon. Analysis revealed that the decreases in dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and Catalase (CAT) activity were significantly positively correlated with the reduction in biomass carbon. Concurrently, the decrease in soil pH showed a significant negative correlation with microbial biomass carbon (MBC) and Sucrase (SUC) activity. (3) Regarding growth traits, although tree height showed no significant differences among clones within the same generation, DBH was generally and significantly inhibited under G2 cultivation. An exception was the 'K13' clone, which remained largely unaffected. In terms of carbon accumulation, G2 cultivation led to a universal decline in biomass carbon across clones; however, the magnitude of reduction in different components (leaf, branch, stem, root) and total biomass carbon varied clone-specifically. Notably, 'K13' exhibited the strongest tolerance, with a significantly smaller decrease in tree biomass carbon compared to the other four clones, which showed substantially lower tree carbon stocks across all components relative to G1 plantations. This indicates that successive cropping of Chinese Fir likely constrains the carbon sequestration capacity of plantations by altering soil nutrient properties, thereby suppressing tree DBH growth and biomass carbon accumulation, likely through reduced net primary productivity. Among the five clones, 'K13' was the least affected, demonstrating its high potential for adaptation to continuous cultivation. These findings provide implications for sustainable forest management by guiding clone selection to mitigate productivity decline under successive cropping.

This study was conducted to investigate the effects of understory cultivation of Rubus chingii Hu (R. chingii) on soil chemical properties and bacterial community succession, aiming to provide a theoretical basis for the promotion of this cultivation model. Experimental plots were established in a forest in Hangzhou City, Zhejiang Province, China. Four treatments were set: pristine forest (CK), and understory planting for one, two, and three years (F1, F2, F3). Soil nutrients and bacterial community composition were analyzed. Compared to CK, understory R. chingii cultivation significantly increased soil pH value and available potassium but decreased organic carbon and available phosphorus. It also altered bacterial community composition. At the phylum level, Pseudomonadota abundance increased significantly, Acidobacteriota decreased with cultivation years, and Actinomycetota peaked in year two then declined. At the genus level, F1 and F2 clustered into a distinct group, with dominant genera including Rhizomicrobium and Acidothermus. Redundancy analysis indicated Pseudomonadota correlated positively with pH value but negatively with organic carbon, Acidobacteriota negatively with pH value, and Actinomycetota negatively with available phosphorus. Network analysis showed F3 had more complex and robust community interactions. Functional prediction suggested F3 enriched nitrogen-cycling and certain photosynthetic bacterial groups. PLS-PM revealed that changes in the composition of dominant bacterial phyla were the primary factor influencing functional gene abundance. Understory cultivation of R. chingii effectively alleviated soil acidification. During this process, changes in the soil chemical environment were accompanied by shifts in bacterial community structure and synchronous reconfiguration of functional networks, progressively establishing a more stable soil micro-ecosystem.

Pleioblastus amarus is a type of woody bamboo with an average internode length of 27-29 cm and a medium diameter of approximately 2 cm, making it an excellent material for crafting flutes. This study investigated the influence of environmental factors on the quality of P. amarus for commercial flute production. We investigated the P. amarus forests in Zhongtai, Hangzhou, China, known for its flute production. The population density (PD) of studied plots varied from 7 to 16 individuals per square meter, and the diameter at breast height (DBH) of samples exhibited a range of 19.25-33.48 mm across the study area. Soil analysis revealed an organic carbon (OC) content ranging from 1.04 % to 3.63 %, alkali-hydrolyzable nitrogen (AN) levels between 48.92 and 160.73 mg/kg, and available potassium (AK) content ranging from 43 to 110 mg/kg. Pearson correlation analysis revealed significant negative correlations (p < 0.05) between DBH and OC, as well as between DBH and AN levels. Pearson correlation analysis showed a significant positive relationship (p < 0.05) between PD and soil AK content. We examined the physical properties of the fourth, fifth, and sixth internodes, the ideal sections for crafting flutes, finding minimal variation and consistent structural integrity among these segments. The material properties were not affected by the environment. Our study provides preliminary information on the effects of the environment on the growth and reproduction of P. amarus. It should aid the appropriate management and cultivation of P. amarus forests, especially those employed as sources of raw materials for flute production.

It has been reported that applying silicon (Si) to agricultural soils can reduce N2O emissions. But, we do not fully understand how this might work in forest ecosystems, especially in Phyllostachys edulis plantations. This study set out to determine how exogenous Si impacts soil nitrification and denitrification. Also, it aimed to assess their separate contributions to N2O emissions. A pot incubation experiment that lasted 28 days was carried out under controlled conditions. The soil used was collected from a bamboo plantation that is intensively managed. The treatments included adding silicon. Also, 3,4-dimethylpyrazole phosphate (DMPP) and acetylene (C2H2) were applied to specifically hold back nitrification and denitrification. We measured the rates of soil N2O emissions, the cumulative fluxes, and the concentrations of NH4+-N, NO3−-N, and NO2−-N. A positive correlation that was significant (p < 0.05) was found between N2O emissions and the levels of soil NO3−-N. Adding Si continued to reduce both the emission rate and the cumulative flux in all of the treatment groups. Also worth mentioning is that the relative contribution of denitrification to N2O emissions dropped from 38.2% to 11.4%. Meanwhile, nitrification’s contribution went up from 61.8% to 88.6%. These findings show that adding Si mainly suppresses denitrification. And, by doing so, it lessens N2O emissions in bamboo plantations. This study underlines the potential of Si amendments. They could be used as an effective management strategy to reduce greenhouse-gas emissions in forest soils. It also provides a scientific basis for making Phyllostachys edulis ecosystems more sustainable.

Non-timber forest products increase forests resource utilization efficiency and promote rural areas economic development. Ganoderma lucidum (Curtis) P. Karst. (Reishi) is a mushroom having great potential being cultivated as NFTPs. However, there is still a lack of effects about cultivating Reishi in forests on soil organic carbon (C) pool and microbial community, which are important for designing sustainable cultivating strategies. Therefore, this study sampled and analyzed soil from forests cultivated Reishi at 2, 4, and 6 years (LZ2, LZ4, and LZ6, respectively), and in reference natural evergreen broad-leaved forest (CK). Our results manifested that, compared with CK, LZ2 slightly increased total organic carbon (TOC), and significantly increased microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC) content by 29.99% and 28.67%, respectively ( P < 0.05). Besides, compared with CK, LZ2 significantly increased the ratio of MBC/TOC and WSOC/TOC by 37.50% and 35.00%, respectively ( P < 0.05). In contrast, these parameters decreased in LZ4 and LZ6 slightly, compared with CK. Consequently, LZ2 had the highest average well-color development values and microbial functional diversity indexes, while these parameters declined in LZ4 and LZ6, compared with CK. As a result, microbial community functional structure in LZ2 was different from that in LZ4, and LZ6, while that in LZ4 and LZ6 showed similarity, according to the principal component analysis and PERMANOVA test.

Soil organic carbon （SOC） and soil total nitrogen （STN） serve as important indicators of the elemental balance within forest ecosystems reflecting soil fertility and quality. Accurate knowledge regarding the spatial variability of regional SOC, STN, and C∶N ratio and their influencing factors is of great significance for precise fertilization and soil health. In this study, a total of 117 topsoil samples （0-20 cm in depth） based on a 1 km×1 km grid were collected in the Torreya grandis cv. Merrillii plantation in Zhejiang Province. A combination of multi-dimensional statistical approaches （random forest model, structural equation model, redundancy analysis, and variation partitioning analysis） and diverse spatial analytical techniques （geostatistics, Moran's I index, etc.） were applied to reveal the spatial distributions and influencing factors of SOC, STN, and C∶N ratio in the Torreya. grandis cv. Merrillii region. The results showed that the average ω（SOC）, ω（STN）, and C∶N ratio were 17.63 g·kg-1, 1.48 g·kg-1, and 12.65, respectively, and their coefficients of variation were 68.08%, 67.41%, and 46.03%, respectively, indicating a moderate degree of variability. In general, the SOC, STN, and C∶N ratio of the Torreya grandis cv. Merrillii plantations were at an intermediate level in the national plantation. The semi-variance results showed that the nugget/sill values of SOC, STN, and C∶N ratio were 49.98%, 45.88%, and 49.93%, respectively, demonstrating a moderate level of spatial autocorrelation. The spatial distribution results showed that SOC, STN, and C∶N ratio decreased from northeast to southwest, with the majority of the region exhibiting above-medium fertility levels of SOC. The results of correlation analysis and redundancy analysis indicated that AN, AP, and AK were significantly correlated with both SOC, STN, and C∶N ratio （P&lt;0.05）. The results of random forest, structural equation model, and variation partitioning analysis evidenced that the main influencing factors of SOC and STN were soil-available nutrients （AN, AP, and AK）. Therefore, our results could provide important insights for enhancing soil carbon and nitrogen pools in special plantations in Zhejiang Province, enhancing the capacity of plantations to adapt to regional climate change through ecological measures such as appropriate fertilization practices and strategic understory vegetation cultivation.

[Objective]In order to reduce the use of chemical nitrogen fertilizer,pot experiment was conducted to explore the effects of nitrogen(N)reduction combined with different ratios of biochar on improvement of soil nutrient and increase of rice yield under the condition of returning milk vetch to the field.The aim is to clarify the optimal nitrogen reduction and biochar addition ratio that are more conducive to fertilization and yield increase on the basis of replacing part of nitrogen fertilizer with Chinese milk vetch.The results could be used to provide scientific basis for production.[Method]A two-factor rice pot experiment was conducted,and four(0.25%,0.5%,1%,2%)biochar addition ratios and three(10%,20%,30%)N reduction ratios during topdressing were set.A total of 13 treatment combinations were set,and each treatment was repeated four times.A total of 52 pots were grown for 120 days.The effects of each treatment on soil physicochemical properties,rice yield and characters were compared after rice ripening.[Result]The soil pH(P＜0.01)was significantly increased by 12.02%compared with that of CK in the field with 30%N reduction combined with 2.0%biochar.The contents of soil organic matter(SOM),available phosphorus(AP)and available potassium(AK)were significantly increased by 20%N reduction combined with 2.0%biochar(P＜0.01),and the contents of soil total N(P＜0.05)were significantly increased by 38.8%,107.2%,25.4%and 24.9%compared with that of CK.The content of alkali N was significantly increased by 49.6%when 20%N reduction was combined with 0.5%biochar(P＜0.01).The highest yield was obtained when 30%N reduction 30%was combined with 1.0%biochar,which was significantly increased by 18.7%(P＜0.01)compared with that of CK.However,the application of low biochar(0.25%biochar)was more beneficial to above-mentioned biomass accumulation,which was significantly increased by 90.04%compared with that of CK(P＜0.01).Correlation analysis showed that soil organic matter,available phosphorus and available potassium in this study were the main soil environmental factors(P＜0.05,r＞0.5)to improve rice yield.[Conclusion]Combined application of milk vetch,N reduction and biochar has a significant effect on fertilizer cultivation and yield increase.The application of 20%nitrogen reduction combined with 2.0%biochar under Chinese milk vetch returning to the field is more conducive to improving the nutrient content of paddy soil.It can reduce N loss and promote rice growth and yield increase,but excessive application of biochar has a certain inhibitory effect on rice yield and biomass.30%N reduction combined with 1.0%biochar in topdressing had the optimal effect on rice yield.

In recent years, a large number of Moso bamboo ( Phyllostachys pubescens ) plantations have been abandoned, resulting in the occurrence of vegetation succession. However, the understory diversity, changes in soil properties and soil microbial community composition, and interrelationships after abandonment are still unknown. In this study, soil samples from Moso bamboo plantations with abandonment at 0, 10, 20, and 30 years were collected in a subtropical region of southeastern China. The stand structure, understory, soil properties, and soil bacterial community of Moso bamboo plantations were analyzed. The high-throughput sequencing of 16S rRNA was used to study soil bacterial community, and a partial least squares path model (PLS-PM) was constructed to express the causal relationship among different factors and soil bacterial diversity. With the increase of abandonment years, the density of Moso bamboo and litter biomass increased while the average diameter at breast height decreased. The Pielou index of the shrubs and herbs increased in 10Y ( p < 0.05). The soil organic carbon, available phosphorus, and potassium increased significantly, while soil bulk density decreased significantly after abandonment. The Shannon, Simpson, and Chao1 index of soil bacterial communities increased first (10Y) and then decreased (20Y and 30Y). Further, the redundancy analysis and PLS-PM indicated that soil properties were the key factors affecting the soil bacterial diversity. Overall, these results suggested that abandonment could improve soil quality in the short term; however, it was not conducive to the sustainable development of Moso bamboo plantations in the long term.

为探究不同光质作为烟草生长光源的应用效果,在人工气候室条件下,以本生烟草为试验材料,设置 3 种不同光质光源 LED-v1(R1.2/B1,R3.4/FR1)、LED-v2(R7.4/B1,R2.9/FR1)、LED-v1/v2(R2.3/B1,R3.1/FR1)处理,分析烟草的生长指标对不同光质的响应.结果表明:LED-v1/v2处理本生烟草的株高、茎粗、叶面积、叶片数、生物量显著优于其他处理.低R/FR和低R/B光质能提高烟草叶片的含N量,有助于合成有机物及提高抗逆性,提高烟草的经济品质.适当降低LED-v1/v2光质R/B和R/FR值更有利于烟草的生长和品质的提升.光合反应中心Ⅱ(ΦPSⅡ)、表观电子传递速率(ETR)、PSⅡ最大光化学量子产量(Fv/Fm)等叶绿素荧光指标在不同的处理间无显著差异.综上,烟草生长最适合的人工光源为LED-v1/v2(R2.3/B1,R3.1/FR1).

In order to grasp the impact of different soil management on the loss of nitrogen and phosphorus in runoff in tea gardens, and provide a basis for tea garden management, four treatments were set up in the tea gardens in Qiandao Lake area, including conventional fertilization（CF）, 50% organic fertilizer instead of chemical fertilizer（COF）, conditioner application（CFC） on the basis of CF, and straw mulching（CFM） on the basis of CF,three replicates in each trial. Under the condition of natural rainfall, the runoff of different treatments, nitrogen and phosphorus concentrations in the runoff water were monitored, and the losses of nitrogen and phosphorus were calculated. The results showed that the surface runoff of tea gardens was between 1 049.3 and 1 417.3 m~3·hm -2 ,and straw mulching significantly reduced the surface runoff of tea gardens by 25.4%-26.0%（P ＜ 0.05）. The losses of nitrogen and phosphorus in surface runoff ranged from 1.48 to 2.23 kg·hm -2 and 0.39 to 0.54 kg·hm -2 ,respectively. Compared with CF, the nitrogen losses of COF, CFC and CFM treatments were reduced by 24.8%,11.1%, and 33.9%, respectively, and phosphorus loss decreased by 26.5%, 24.8% and 29.8%, respectively. The concentrations of nitrogen and phosphorus in runoff water were significantly negatively correlated with surface runoff（P＜0.01）, and the correlation coefficients ranged from -0.55 to -0.75.

A long-term field experiment was conducted at a Chinese hickory (Carya cathayensis) plantation from 2011 to 2021, with the purpose of researching the effects of long-term sod cultivation on hickory plantation soil fungal communities and enzyme activities and providing experience for ecological management in other plantations. Sod cultivation included oilseed rape (Brassica chinensis, BR), Chinese milk vetch (Astragalus sinicus, AS), and oilseed rape+Chinese milk vetch (BA), and clear tillage (CT) served as a contrast. The soil fertility, fungal community composition and diversity, and soil enzyme activities were determined. The results showed that:① long-term sod cultivation significantly increased soil nutrient contents and availability, and pH increased variably from different sod cultivation treatments (P<0.05). ②The soil fungal community composition was changed by long-term sod cultivation. The relative abundance of Ascomycota, which utilized the readily decomposed organic matter, was increased, whereas the relative abundance of Basidiomycota, which degraded stubborn organic matter, decreased. Long-term sod cultivation shifted the soil dominant genera, as BR and BA increased the relative abundance of somemycorrhizal fungi that could form mutually beneficial structures with dominant plant genera after sod cultivation,whereas AS increased the relative abundance of saprophytic fungi that could decompose the remains of dead plants and animals. The soil fertility factors including pH, available nitrogen, microbial biomass nitrogen, and water-soluble organic carbon were revealed to have a significant influence on the soil fungal composition (P<0.05). ③ Moreover, long-term sod cultivation stimulated the activities of soil enzymes involved in the carbon and nitrogen cycle. Apart from BA, sod cultivation treatments decreased the activities of alkaline phosphatase, which was involved in the soil P turnover. The correlation analysis demonstrated that the correlations between activities of enzymes decomposing carbon and nitrogen and soil fertility were significant (P<0.05 or P<0.01). The activities of phosphatase were positively correlated with soil microbial biomass carbon and nitrogen. Long-term sod cultivation could improve soil nutrient content and availability, optimized soil fungal community structure, and promoted soil nutrient turnover enzyme activities.

为了解避雨栽培对杨梅(Myrica rubra)人工林叶片和土壤的碳(C)、 氮(N)、 磷(P)生态化学计量的影响,以杭州市临安区杨梅人工林为对象,设置避雨栽培与露地栽培2个处理3次重复的试验,分别于5、8月定位采集并分析了叶片和土壤碳(C)、氮(N)、磷(P)含量.结果表明,相同月份的杨梅叶片碳、氮、磷、碳氮比、碳磷比、氮磷比在不同栽培模式间没有显著性差异(P>0.05),8月份叶片氮、碳磷比、氮磷比显著高于5月(P<0.05);林地土壤碳、氮、磷、碳氮比、碳磷比、氮磷比在不同栽培模式间的差异没有达到显著性水平(P>0.05);叶片碳、 氮含量与土壤碳含量间具有显著负相关(P<0.05),相关系数分别为-0.5832、-0.6364.综上,避雨栽培并没有改变杨梅叶片和土壤碳、 氮、 磷生态化学计量特征;杨梅生长的限制性元素是磷,在生产经营过程中,可适当增施磷肥.

By taking the public welfare forest land in Jiangshan City of Zhejiang Province as the research object, based on the measured data of fixed sample plots and sublot of public welfare forest, the water conservation capacity and value of litter layer and soil layer in different forest stands were quantitatively measured and analyzed. The results showed that the effective interception amount of litter in different forest types of public welfare forest in Jiangshan City was coniferous and broad-leaved mixed forest＞broad-leaved forest＞Chinese fir forest＞pine forest＞moso bamboo forest. In the same depth of soil layer, the difference of soil physical properties and water holding capacity was not obvious. The soil layer contributed more than 99% of the water conservation quantity of forest land. The order of water conservation ability was coniferous and broad-leaved mixed forest＞broad-leaved forest＞moso bamboo forest＞Chinese fir forest＞coniferous mixed forest＞pine forest＞shrub forest. The total annual water conservation quantity of public welfare forests in the whole city was 18 7,7869 million tons, with the value quantity of 1.979 billion yuan. The water conservation quantity per unit area was about 2 813 t·hm -2 , and the value quantity per unit area was about 29,700 yuan·hm -2 . In Jiangshan City, the water conservation capacity of public welfare forest was stronger in the east, while the water conservation capacity of public welfare forest in the north was relatively weak.