Soil microbial heterotrophic respiration (HR), a crucial carbon flux to the atmosphere, is closely related to microbial community traits. However, community level microbial traits associated with such process remain understudied across forest biomes. Here, we accessed microbial traits influence on HR across a forest climatic gradient in China. We found that microbial HR showed distinct differentiation along an environmental gradient, which were highest in temperate forest Maoer mountain (1067.95 mg C kg−1) and lowest in tropical forest Xishuangbanna (178.83 mg C kg−1). At the community level, microbial HR was tightly related to microbial biomass and composition, and genomic traits. Notably, the HR was positively correlated with guanine-cytosine base pair content, but negatively correlated to the average 16S rRNA copy number and the average genome size of microbes (P < 0.05). Moreover, among the forests, soil organic carbon and alkyl-C/O-alkyl-C ratio were the crucial variables in explaining HR, which attributed to their effects on microbial composition and genomic traits. Overall, microbial genomic traits at the community level play an important role in understanding HR. Our findings elucidate new evidence on the mechanisms driving soil carbon fluxes and enhance predictions of soil carbon responses to future climatic change.
Abstract Forest disturbance and climate change have caused a growing abundance of lianas in tropical and many temperate forests, which imparts a sense of urgency to explore the factors that control liana community assembly. Here, we examined the changes in liana community structure and functional traits during secondary succession in a warm temperate oak forest, and then analyzed how these varied with forest structural and soil properties. Liana species showed lower stem density in the late stage (85 ind. ha−1) than the earlier two stages (190 ind. ha−1 and 230 ind. ha−1, respectively). Liana diversity also decreased along the succession. Compared with the earlier successional stages, lianas in the late successional stage invested more in acquisitive stem (lower wood density) and root (lower root carbon content). The decreases in liana abundance and wood density were strongly related to the decreasing tree diversity and the increasing canopy cover, tree diameter and tree height, with weak relationships with soil properties. These results demonstrate that forest structure is the main driver of liana community structural and functional assembly during forest succession, and is likely to shape liana community mainly by filtering stem traits.
Soil microbes are the planet's most abundant, diverse, and functionally vital organisms, yet only a small portion of these microbes actively drive soil processes. While resource availability is known to influence microbial physiological traits under multiple soil processes, how aboveground resource input structures the spatial distribution of the soil active microbiome remains virtually unknown. Here, we report the results from a continental standardized soil sampling at 601 sites across major biomes in China. We measured the proportion of the active microbiome (SAM%) using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) staining by flow cytometry and simultaneously evaluated their main environmental drivers. On average, < 2% of all microbes constitute the active soil microbiome. Forests supported the most active soil microbiomes (> 2%), while cropland harbored the lowest (< 1%). Aboveground productivity, peaking in tropical warmer and wetter regions, was the major environmental factor explaining variation in the active soil microbiome. Our study suggests that a less productive planet may result in drastic reductions in the active soil microbiome with consequences for supporting ecosystem function and biogeochemical cycles under climate change.
Soil viruses control the dynamics and metabolism of their hosts, strongly modifying carbon and nutrient cycling as well as soil biochemistry. Warming specifically affects viruses and their hosts, but the consequences of climate warming on the virus-host interactions, and for soil functions, remain unknown. We investigated the viral communities and the virus-host interactions under warming in situ based on a forest soil column translocation experiment. The abundance of the Petitvirales (DNA viruses) decreased by 25%, but that of the Durnavirales and Martellivirales (RNA viruses) strongly increased. The DNA viral lysogenic signals and RNA viral lytic proteins increased in soil, indicating the opposite lifestyles of DNA and RNA viruses. Correspondingly, the DNA abundance of viral hosts increased, whereas RNA viral hosts remained stable. The high DNA viruses/host ratios reflect very intensive interactions between the virus and host, leading to the drop in the host functions (such as carbon metabolism processes and nitrogen and phosphorus cycles) up to 43%. In contrast, the functions of the hosts for RNA viruses increased by up to 48%. The fundamental difference in behaviour of DNA and RNA viruses is that the former use mainly lysogenic, whereas the latter lytic, lifestyles and thus control the responses of host communities to warming. Conclusively, the opposite response of DNA and RNA viruses to warming in abundance, lifestyle, and interactions with hosts leads to divergent changes in nutrient fluxes in soil. These new perspectives on viral regulations of microbial communities and their function under soil warming reveal the undeniable role of viruses in microbial ecology.
Soil microbes, particularly active microbes, play a crucial role in conserving soil carbon under climate change, especially in forest ecosystems, constituting over 50
Shrubland functions as an important carbon sink. However, uncertainties have still persisted regarding shrubland C storage and its underlying drivers. In this study, we conducted a field survey encompassing 45 sites to investigate all sectors of C stocks in shrublands distributed in northern China, in order to accurately estimate the regional C storage and to explore the potential drivers. Our results showed that the total C density of shrubland was 78.78 Mg C ha(-1), with soil C density, vegetation C density and litter C density contributing 75.16, 2.99 and 0.64 Mg C ha(-1), respectively. Distinct C density sectors were driven by different factors: vegetation C density was primarily driven by plant community richness, litter C density by shrub diversity and soil C density by total annual sunshine and soil total phosphorus in our study. Climate factors, plant community traits and soil properties independently explained 5.15%, 6.79% and 23.73% variation of the shrubland ecosystem C density, respectively. Furthermore, the interactions between community structural traits and climate factors, as well as between community structural traits and soil properties, can explain 10.44% and 18.50% of the variation, respectively. Our findings, based on direct field measurements, refined estimates of C storage in shrubland ecosystems in northern China, and these findings provided crucial data for the validation and parameterization of C models both within China and globally.
AbstractClimbing plants are important components of tropical and many temperate forest ecosystems. Current studies regard climbing plants as a single ecological plant type and ignore the ecological differences resulting from their climbing mechanisms, which may lead to a misrepresentation of the role of climbing plants in forest dynamics. Based on behavioral traits and economic traits of climbing plants, we test the hypothesis that tendril climbers and stem twiners are characterized by different resource acquisition strategies. We quantified and compared 4 behavioral traits and 7 economic traits of four stem twining vines and four tendril vines in a temperate oak forest and further tested their differences in resource acquisition strategy. Our study found that tendril vines were scattered in a group distinct from stem twining vines along the first axes of the principal component analysis using four behavioral traits and seven economic traits, being located at the more acquisitive end with more hosts, a larger distance to length ratio of stem, higher leaf and root nitrogen concentrations, and lower leaf carbon content, while stem twining vines showed the opposite trends. These results indicate that tendril vines have a more acquisitive strategy than stem twining vines. The findings suggest a functional variability among the different climbing mechanisms, and which should be accounted for in future studies.
Mineral protection mechanisms are important in determining the response of particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) to temperature changes. However, the underlying mechanisms for how POC and MAOC respond to temperature changes are remain unclear. By translocating soils across 1304 m, 1425 m and 2202 m elevation gradient in a temperate forest, simulate nine months of warming (with soil temperature change of +1.41 degrees C and +3.91 degrees C) and cooling (with soil temperature change of-1.86 degrees C and-4.20 degrees C), we found that warming translocation significantly decreased POC by an average of 10.84 %, but increased MAOC by an average of 4.25 %. Conversely, cooling translocation led to an average increase of 8.64 % in POC and 13.48 % in MAOC. Exchangeable calcium (Caexe) exe ) had a significant positive correlation with POC and MAOC during temperature changes, and Fe/Al-(hydr)oxides had no significant correlation or a significant negative correlation with POC and MAOC. Our results showed that POC was more sensitive than MAOC to temperature changes. Ca exe mediated the stability of POC and MAOC under temperature changes, and Fe/Al(hydr)oxides had no obvious protective effect on POC and MAOC. Our results support the role of mineral protection in the stabilization mechanism of POC and MAOC in response to climate change and are critical for understanding the consequences of global change on soil organic carbon (SOC) dynamics.
The life strategies of bacterial communities determine their structure and function and are an important driver of biogeochemical cycling. However, the variations in these strategies under different soil resource conditions remain largely unknown. We explored the bacterial life strategies and changes in structure and functions between Antarctic soils and forest (temperate, subtropical, and tropical) soils. The results showed that the weighted mean rRNA operon copy number in temperate soils was 19.5% lower than that in Antarctic soils, whereas no significant differences were observed among Antarctic, subtropical, and tropical soils. An unexpected result was that bacterial communities in Antarctic soils tended to be copiotrophs, such as Actinobacteriota and Bacteroidota, whereas those in temperate soils tended to be oligotrophs, such as Acidobacteriota and Chloroflexi. Functional predictions showed that in comparison to copiotrophs in Antarctic soils, temperate-inhabiting oligotrophic bacteria exhibited an 84.2-91.1% lower abundance of labile C decomposition genes (hemicellulose, cellulose, monosaccharides, and disaccharides), whereas a 74.4% higher abundance of stable C decomposition (lignin). Genes involved in N cycling (nitrogen fixation, assimilatory nitrate reduction, and denitrification) were 24.3-64.4% lower in temperate soils than in Antarctic soils. Collectively, our study provides a framework for describing the life strategies of soil bacteria, which are crucial to global biogeochemical cycles.
• CH 4 emission rates followed an increased pattern during the growing season at Tibetan Plateau. • Unique genes carried by abundant species were positively correlated with CH 4 emission rates. • Climate factors influenced CH 4 emission rates by regulating microbial community and their genes. Microorganisms play pivotal roles in soil methane (CH 4 ) emissions and their functional genes are origins of a key mechanism for soil CH 4 -cycling. However, understanding of the roles of specific genes (e.g., unique or shared genes carried by species) underlying CH 4 -cycling remains elusive. Here, we measured CH 4 emission rates and investigated variations in microbial community and the abundance of genes carried by species during the growing season in alpine meadow on the Tibetan Plateau. We discovered that CH 4 emission rates increased from 394.4, 745.9, and 1 092.7 µg CH 4 m −2 h −1 , in April, June, and August, respectively, and had a positive correlation with unique genes carried by abundant species during the growing season. Moreover, we found that unique genes carried by abundant species involved in methanogenesis processes have a higher abundance than methanotrophic processes. Further analysis indicated that climate factors (i.e., mean monthly temperature (MMT) and mean monthly precipitation (MMP)) influenced microbial community and their functional genes, and therefore affected the CH 4 emission rates. Overall, the present study provides a novel insight into the variation of soil CH 4 emissions from a functional gene perspective, highlighting the important roles of unique genes carried by abundant species in CH 4 emissions in the Tibetan Plateau under seasonal variation.
Assessing plant diversity during community succession based on plant trait and phylogenetic features within a community (alpha scale) and among communities (beta scale) could improve our understanding of community succession mechanism. However, whether changes of community functional diversity at alpha and beta scale are structured by different traits and whether integrating plant traits and phylogeny can enhance the ability in detecting diversity pattern have not been studied in detail. Thirty plots representing different successional stages were established on the Loess Plateau of China and 15 functional traits were measured for all coexisting species. We first analyzed the functional alpha and beta diversity along succession by decomposing species trait into alpha and beta components and then integrated key traits with phylogenetic information to explore their roles in shaping species turnover during community succession. We found that functional alpha diversity increased along successional stages and was structured by morphological traits, while beta diversity decreased during succession and was more structured by stoichiometry traits. Phylogenetic alpha diversity showed congruent pattern with functional alpha diversity because of phylogenetic conservation of trait alpha components (variation within community), while beta diversity showed incongruent pattern due to phylogenetic randomness of trait beta components (variation among communities). Furthermore, only integrating relatively conserved traits (plant height and seed mass) and phylogenetic information can raise the detecting ability in assessing diversity change. Overall, our results reveal the increasing niche differentiation within community and functional convergence among communities with succession process, indicating the importance of matching traits with scale in studying community functional diversity and the asymmetry of traits and phylogeny in reflecting species ecological differences under long-term selection pressures.
Carbohydrate-active enzymes (CAZymes) mediate carbohydrate turnover and play vital roles in plant- and microbial-derived carbon decomposition. However, the changes of genes that encoding enzymes for plant- and microbial-derived carbon decomposition along environmental gradients remains unclear. We used metagenomic sequencing to explore changes in genes encoding enzymes for carbon decomposition in five forest sites along an elevational gradient (1503–3182 m) on Qinling Mountain, China. The genes encoding CAZymes showed various patterns along the elevational gradient. In particular, the abundance of genes encoding auxiliary enzymes and glycoside hydrolases decreased with increasing elevation. The abundance of genes encoding enzymes for plant- and fungi-derived carbon decomposition was higher at low elevations than at high elevations, whereas the abundance of genes encoding enzymes for bacteria-derived carbon decomposition was higher at high elevations than at low elevations. The results indicate contrasting patterns of fungal- and bacterial-derived carbon decomposition with elevation. Proteobacteria and Acidobacteria were the dominant species that decomposed dead plant and microbial biomass. Moreover, our results reveal that soil properties (i.e., ammonium nitrogen and bulk density) and vegetation properties dominated the CAZymes gene distribution along the elevational gradient. Bacteria- and fungi-derived carbon decomposition potentials show contrasting elevational patterns in forest soils; soil and vegetation properties are common controls for the elevational patterns.
Microbial nitrogen transformation processes in grasslands are important nitrous oxide (N2O) sources on the Tibetan Plateau. Different microorganisms carrying various functional nitrogen (N) cycling genes colonize different soil types and have varying impacts on N2O emissions. However, the role of specific microbial com-ponents such as unique and shared microbial species, in N2O flux in alpine grassland soils remains understudied. Thus, we combined gas chromatography-based static opaque chamber methods with metagenomic sequencing to investigate the role of unique and shared microbial species carrying N-cycling genes in N2O emissions from two alpine grassland types on the Tibetan Plateau. Our results showed that the N2O flux in the alpine meadows (9.48 x 10-9 g m- 2 h-1) was higher than that in the alpine steppes (4.21 x 10-9 g m- 2 h-1). Furthermore, our study revealed a significant negative correlation between the abundance of unique microbial species and the N2O flux in alpine steppes. In contrast, the abundance of shared microbial species was significantly and positively correlated with N2O flux. The unique microbial species in the phyla Chloroflexi and Actinobacteria carried the ureC, nasA and nirB genes, which could consume nitrogen substrates in forms other than producing N2O, which could explain the N2O reduction seen in the alpine steppes. In addition, the higher abundance of shared microbial species in the phyla Proteobacteria, Actinobacteria, Thaumarchaeota and Acidobacteria carried genes encoding denitrification pathways (nirK, narG, and norB) could interpret the higher N2O emissions in the alpine meadows. In addition, our study revealed that the soil substrate contents (e.g., soil organic carbon and total nitrogen) and soil environment factors (e.g., soil pH and soil moisture) were potentially important drivers of N2O emissions in soil via their regulation of the composition of unique and shared microbial communities carrying N-cycling genes. Collectively, our results suggested that identifying the unique and shared microbial species carrying different N-cycling genes could provide potential biological strategies for mitigating N2O emissions in alpine grasslands, such as blocking the growth of shared microbial species. Future management practices for mitigating N2O emissions in alpine grassland should also focus on adopting appropriate nutrient management strategies, such as balanced fertilization, to prevent excessive nutrient. Our findings provide insights for further elucidating the different potential regulatory effects of unique and shared microbial species on emissions under the control of the soil environment in different types of grasslands on the Tibetan Plateau.
Highly variable soil microbial respiration among grasslands has been identified as a major cause of uncertainty in regional carbon (C) budget estimation in the Qinghai-Tibetan Plateau; microbial metabolism mechanisms might explain this variation, but remain elusive. Therefore, we investigated soil CO2 production in incubated soils and detected the associated functional genes at four sampling sites from two major alpine grasslands on the Qinghai-Tibetan Plateau. The results showed that the cumulative CO2 emissions from alpine meadow soils were 71 %-83 % lower than those from alpine steppe soils. Both the enriched genes abundance encoding fermentation and glycolysis (Embden-Meyerhof pathway (EMP)) and the diminished genes encoding tricarboxylic acid cycle (TCA) and phosphate pentose pathway (PPP) explained the CO2 emission reduction in the alpine meadow soils. The EMP: PPP and fermentation: TCA cycle ratios in alpine meadow soils were 1.45- and 1.50-fold higher than those in alpine steppe soils, respectively. Such shifts in metabolic pathways were primarily caused by the increasing dominance of an unknown species of Desulfobacteraceae with high glycolytic potential, carrying a higher abundance of ldh genes during fermentation. These unknown species were promoted by warmer temperatures and higher precipitation in the alpine meadows. Further studies on the unknown species would enhance our understanding and predictability of C cycling in alpine grasslands.
The alpine grasslands account for approximately 54.5% of the total carbon in China’s grasslands, and carbohydrate-active enzymes (CAZymes) play key roles in the turnover of carbon. However, the variation and factors influencing gene-encoding enzymes for plant- and microbial-derived carbon decomposition in alpine steppes and alpine meadows remain unclear. Here, the trends in microbial carbohydrate-active enzymes (CAZymes) and their responses to the decomposition of biomass of different origins were studied using metagenomics in the alpine steppes and alpine meadows on the Tibetan Plateau. Our results revealed the abundance of GTs and CBMs was higher in the alpine steppes than in the alpine meadows, whereas AAs were higher in the alpine steppes than in the alpine meadows. Soil properties (i.e., soil water content, soil ammonium nitrogen, and nitrate nitrogen) highly related to CAZyme genes (GTs, CBMs, and AAs) showed an abundant pattern between the alpine steppes and alpine meadows. Moreover, our results indicated that the relative abundance of genes encoding CAZymes involved in the decomposition of plant- (indicated by cellulose, hemicellulose, and lignin) and fungal-derived carbon (indicated by chitin and glucans) was higher by 8.7% and 10.1%, respectively, in the alpine steppes than in the alpine meadows, whereas bacterial-derived carbon (indicated by peptidoglycan) was lower by 7.9% in the alpine steppes than in the alpine meadows. Soil water content (SWC), nitrate nitrogen (NO3−), and pH influenced on the abundance of CAZyme genes involved in the decomposition of plant-, fungal-, bacterial-derived carbon. In addition, the dominant microbial phyla (Actinobacteria, Protebacteria, and Acidobacteria) mineralized carbon sources from plant- and microbial-derived carbon through their corresponding CAZyme families. In conclusion, our study compared plant- and microbial-derived carbon decomposition potentials and influencing factors to illustrate the contribution of dead biomass to carbon accumulation in alpine grasslands.
Aims Under the background of changing carbon cycle process in forest ecosystems caused by global environmental change, the microbial carbon use efficiency(CUE) in forest rhizosphere soil is critical to determine the strength of microbial anabolism and catabolism in forest ecosystems. However, the variation and influencing factors of microbial CUE in rhizosphere soils at different altitudes remain undetermined.Methods Rhizosphere soil at six different altitudes spanning four forest belts in Taibai Mountain was sampled to determine the physical and chemical properties, extracellular enzyme activity, and characteristics of microbial community and vegetation. Based on the stoichiometric ratio, the soil microbial CUE was estimated. Furthermore,the variation in microbial CUE of rhizosphere soil along the altitude gradient was analyzed to quantify the influencing factors of microbial CUE.Important findings The results showed that the microbial CUE of rhizosphere soil exhibited an overall upward trend with the increase in altitude. The microbial CUE increased by 4.36% from 0.505 at the lowest altitude to 0.527 at the highest altitude, but decreased at 1 603 and 2 405 m. Based on the Mantel analysis, we identified four categories of factors(i.e., altitude, soil matrix, vegetation and microbe) that related to microbial CUE in rhizosphere soil. The variations of microbial CUE in rhizosphere soil are affected by multiple environmental factors, with the dominant factor being soil matrix(such as dissolved organic carbon(DOC) content, ammonium nitrogen(NH 4 + -N) content), followed by vegetation. Furthermore, the altitude factor and the microbial factor explained 2.6% and 3.1% of the CUE change, respectively. Although the microbial factors exerted no significant impact on microbial CUE, soil matrix, vegetation and microbe jointly explained 47.0% of the microbial CUE change. The variance partitioning analysis(VPA) quantitatively revealed the contribution of environmental factors to the change of microbial CUE, where soil matrix and vegetation explained 17.0% and 5.7% of the variation, respectively. While the interaction between soil matrix and vegetation accounted for 31.9% of the changes in microbial CUE. The above results indicated that the high-altitude rhizosphere soil in Taibai Mountain has a high carbon sequestration potential, and the carbon sequestration of forest rhizosphere soil may decrease with the intensification of global warming. The vertical temperature difference and the vertical differentiation of the vegetation belt induced by altitude gradient will alter the growth and metabolism environment of microorganisms in the rhizosphere soil. The comprehensive effect of multiple environmental factors dominated by soil matrix impacts the CUE of soil microorganisms, and ultimately changes the assimilation and catabolism processes of soil carbon. The results of this study can provide a scientific basis for the carbon assimilation capacity and carbon sequestration potential of forest soil microorganisms in Qinling Mountains, as well as the forest soil carbon cycle under the background of global change.
Aims Comparing functional traits of coexisting tree species in natural forests can reveal the adaptation strategies of different tree species to different habitats,which is essential for understanding the coexistence mechanism of the local forest community and guiding forest restoration. Methods In this study,we compared the functional traits of five coexisting tree species in a Quercus aliena var.acuteserrata forest,the zonal vegetation in the Qinling Mountains,and further examined the difference in the traits space defined by the first two principal component analysis(PCA)axes to reveal the differences of these tree species in ecological strategies. Important findings The results showed that there were obvious differences in the above-and belowground functional traits of different tree species,especially in the strategies of leaf resource acquisition and defense.Specifically,Acer davidii tended to have more acquisitive leaf traits and fine root traits,while Carpinus cordata was relatively more conservative in leaf and fine root traits.Lindera obtusiloba was inclined to have leaves with high resistance and defense ability,while leaves of Cornus kousa subsp.chinensis showed low resistance and defense ability.The dominant species,Q.aliena var.acuteserrata,occupied the middle position along the strategy gradient.The differences in the functional traits and their combinations of coexisting tree species in Q.aliena var.acuteserrata forest reflect their differences in ecological strategies and niches,which may contribute to their stable coexistence.
Arbuscular mycorrhizal fungi (AMF), playing critical roles in carbon cycling, are vulnerable to climate change. However, the responses of AM fungal abundance to climate change are unclear. A global-scale meta-analysis was conducted to investigate the response patterns of AM fungal abundance to warming, elevated CO2 concentration (eCO(2)), and N addition. Both warming and eCO(2) significantly stimulated AM fungal abundance by 18.6% (95%CI: 5.9%-32.8%) and 21.4% (15.1%-28.1%) on a global scale, respectively. However, the response ratios (RR) of AM fungal abundance decreased with the degree of warming while increased with the degree of eCO(2). Furthermore, in warming experiments, as long as the warming exceeded 4 degrees C, its effects on AM fungal abundance changed from positive to negative regardless of the experimental durations, methods, periods, and ecosystem types. The effects of N addition on AM fungal abundance are -5.4% (-10.6%-0.2%), and related to the nitrogen fertilizer input rate and ecosystem type. The RR of AM fungal abundance is negative in grasslands and farmlands when the degree of N addition exceeds 33.85 and 67.64 kg N ha(-1) yr(-1), respectively; however, N addition decreases AM fungal abundance in forests only when the degree of N addition exceeds 871.31 kg N ha(-1) yr(-1). The above results provide an insight into predicting ecological functions of AM fungal abundance under global changes. (C) 2021 Elsevier B.V. All rights reserved.
Microorganisms play important roles in phosphorus (P) cycling via their regulation of P uptake and transport, P mineralization and solubilization, and the mediation of P deficiency in forest biomes. However, the dynamics of microbial P functional genes and the underlying regulatory mechanisms in different forest biomes (e.g., temperate vs. subtropical) have yet to be sufficiently clarified. In this study, we applied a metagenomics approach to investigate changes in the abundance of three microbial P functional gene groups (P-starvation response regulation genes, P-uptake and transport genes, and P-solubilization and mineralization genes) along a subtropical–temperate gradient of forest biomes (23°N–45°N) in China. Our results revealed that the abundances of P-starvation response regulation genes in temperate forest biomes were significantly higher than those in the subtropics (p < 0.05), although not in the cases of the other two P functional gene types (p > 0.05). Moreover, in both temperate and subtropical forests, Acidobacteria, Actinobacteria, Proteobacteria, and Verrucomicrobia were identified as key phyla associated with P cycling. Furthermore, in both forest biomes, microbial community α-diversity was significantly positively correlated with P-starvation response regulation genes (p < 0.05), whereas α-diversity was significantly positively related to P-uptake and transport genes in temperate forest biomes (p < 0.001), although not in subtropical forests (p > 0.05). In addition, we found that whereas soil substrates showed significant negative relationships with P-solubilization and mineralization genes in temperate forest biomes (p < 0.05), this was not the case in subtropical forests. Collectively, these findings indicate that the responses of microbial P functional genes to the environmental variation in temperate forests are more sensitive than those in subtropical forests, thereby providing a theoretical foundation for further elucidation of the differential regulatory roles of these genes in different forest biomes.