Abstract This study examines long-term carbon sequestration in the forest ecosystems of Hainan Island from 1990 to 2020 using the InVEST model and a geographic detector technique. We analysed changes in land use and forest cover, observing an 85.78%, 87.55%, and 256.96% decrease in undeveloped, shrub-covered, and burned urbanised land, respectively. Urbanised land increased by 4.01% annually. Forested land decreased by 3.62%, agricultural land expanded by 5.27%, and aquatic bodies decreased by 2.05%. The forest ecosystems sequestered 335.09–372.80 TgC of carbon, showing an upward trend from 1991 to 1997, a decline from 1997 to 2004, an increase from 2004 to 2010, a decrease from 2010 to 2015, and overall stability from 2015 to 2020. Spatial clustering analysis revealed substantial clustering of carbon sequestration, with central mountainous regions exhibiting elevated levels, coastal areas having diminished levels, the east experiencing higher levels than the west, and the south showing escalated levels compared to the north. Geographical detector analysis identified NDVI, elevation, and slope as primary drivers of spatial variance in carbon sequestration. Forested area changes and government forestry policies played a pivotal role in enhancing carbon sequestration. The combined effect of NDVI and elevation normalisation on vegetation coverage had the most potent synergistic impact.

Assessing carbon stocks in tropical forests is crucial for understanding their role in mitigating climate change. (1) Background: However, existing assessments have underestimated certain factors that can substantially influence carbon dynamics. (2) Methods: This study focuses on one such factor - buttress roots from a tropical forest. (3) Results: Our findings reveal that a significant proportion of trees (69.57%) had 3 to 5 buttress roots per tree. The total biomass of the buttress roots and the aboveground portion of the trees with buttress roots were calculated to be 8.5 tonnes/ha and 10.7 tonnes/ha respectively. The buttress root biomass accounted for 16.18% of the total tree biomass. It was observed that the presence of buttress roots during both the rainy and dry seasons increased the soil organic carbon content by an average of 20.8% in the upslope areas with buttress roots. During the rainy season, the presence of buttress roots did not affect the heavy fraction organic carbon in the soil layers in a statistically significant way. Regardless of the season, the soil respiration rate in the areas without buttress roots was higher than that in the areas with buttress roots. The presence of buttress roots had a positive effect on soil nutrient concentration in all seasons, creating a healthier environment for trees. Tree species with buttress roots had on average 20% higher organic carbon content during both the wet and dry seasons. (4) Conclusions: These findings highlight the importance of considering buttress roots in carbon stock assessments and forest management strategies. By integrating buttress roots into carbon accounting models, we can obtain more accurate estimates of carbon stock potential and develop more effective conservation and restoration strategies for tropical forests.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

In diffuse large B-cell lymphoma (DLBCL), the transcription factor IRF8 is the target of a series of potentially oncogenic events, including, chromosomal translocation, focal amplification, and super-enhancer perturbations. IRF8 is also frequently mutant in DLBCL, but how these variants contribute to lymphomagenesis is unknown. We modeled IRF8 mutations in DLBCL and found that they did not meaningfully impact cell fitness. Instead, IRF8 mutants, mapping either to the DNA-binding domain (DBD) or c-terminal tail, displayed diminished transcription activity towards CIITA, a direct IRF8 target. In primary DLBCL, IRF8 mutations were mutually exclusive with mutations in genes involved in antigen presentation. Concordantly, expression of IRF8 mutants in murine B cell lymphomas uniformly suppressed CD4, but not CD8, activation elicited by antigen presentation. Unexpectedly, IRF8 mutation did not modify MHC CII expression on the cell surface, rather it downmodulated CD74 and HLA- DM, intracellular regulators of antigen peptide processing/loading in the MHC CII complex. These changes were functionally relevant as, in comparison to IRF8 WT, mice harboring IRF8 mutant lymphomas displayed a significantly higher tumor burden, in association with a substantial remodeling of the tumor microenvironment (TME), typified by depletion of CD4, CD8, Th1 and NK cells, and increase in T-regs and Tfh cells. Importantly, the clinical and immune phenotypes of IRF8-mutant lymphomas were rescued in vivo by ectopic expression of CD74. Deconvolution of bulk RNAseq data from primary human DLBCL recapitulated part of the immune remodeling detected in mice and pointed to depletion of dendritic cells as another feature of IRF8 mutant TME. We concluded that IRF8 mutations contribute to DLBCL biology by facilitating immune escape.

The TMEM127 gene encodes a transmembrane protein of poorly known function that is mutated in pheochromocytomas, neural crest-derived tumors of adrenomedullary cells. Here, we report that, at single-nucleus resolution, TMEM127-mutant tumors share precursor cells and transcription regulatory elements with pheochromocytomas carrying mutations of the tyrosine kinase receptor RET. Additionally, TMEM127-mutant pheochromocytomas, human cells, and mouse knockout models of TMEM127 accumulate RET and increase its signaling. TMEM127 contributes to RET cellular positioning, trafficking, and lysosome-mediated degradation. Mechanistically, TMEM127 binds to RET and recruits the NEDD4 E3 ubiquitin ligase for RET ubiquitination and degradation via TMEM127 C-terminal PxxY motifs. Lastly, increased cell proliferation and tumor burden after TMEM127 loss can be reversed by selective RET inhibitors in vitro and in vivo. Our results define TMEM127 as a component of the ubiquitin system and identify aberrant RET stabilization as a likely mechanism through which TMEM127 loss-of-function mutations cause pheochromocytoma.

Hydraulic redistribution (HR), which is the passive movement of water through plant roots from wet to dry soil due to the water gradient, is important for plant physiology and ecohydrological processes. However, our poor knowledge on HR in the humid monsoon climate zone hampers the understanding of the interactions between vegetation and soil water during frequent droughts in evergreen forests. Thus, 5 years (2011-2015) of data, including meteorological parameters and soil moisture content at depths of 10, 30, 50, and 100 cm in soil profiles, were compared at one evergreen broad-leaved forest and at one clear-cutting forest site in south China. Analyses of soil moisture dynamics show that HR was frequently triggered within the depth of 30 cm at the evergreen broad-leaved forest, while (if any) was less visible at the clear-cutting forest site. The daily averaged magnitude of redistributed soil water reached the maximum of 0.81 mm/d. The HR mainly occurred during the monsoon dry season (i.e., from October to March of the following year), possibly indicating a different cause, i.e., asynchronous variations in rainfall and plant water use shape the seasonal patterns of soil water HR, compared to other humid zones. During the study period when HR occurred, the average daily HR in the soil profiles replenished approximately 34-50% of the water consumption in the 0-30 cm soil layer. The simulation results of a distributed hydrology-soil-vegetation model incorporating a HR scheme indicate that evapotranspiration enhanced during drought periods when HR occurred. In the future climate change context, comprehensive investigations on the water fluxes in the atmosphere-vegetation-soil continuum are needed to fully understand the effects of HR on the physiological responses of plants and on the water cycle.

[目的]分析南亚热带常绿阔叶林4个常见树种的生物量器官分配特征,构建各树种单株及不同组分(地上部分和地下部分)生物量模型,以提高其生物量估算准确性.[方法]以位于广州市的南亚热带常绿阔叶林为对象,以该地区森林历史调查数据为依据,结合研究区实际树种组成,选取黧蒴、中华锥、千年桐和华润楠4个常见树种,采用收获法测定各树种不同组分生物量,构建各树种单株及各组分的生物量模型,并探讨树高(H)和木材密度(ρ)作为第二自变量以不同形式加入模型对模型精度的影响.[结果]4个树种树叶生物量占比为5.34％～7.28％,华润楠显著低于黧蒴(P<0.05);4个树种树枝生物量占比为16.82％～24.20％,华润楠显著低于中华锥和黧蒴(P<0.05);4个树种树干生物量占比为47.22％～58.05％,中华锥显著低于其他3个树种(P<0.05);4个树种树根生物量占比为14.25％～22.25％,黧蒴和千年桐显著低于中华锥和华润楠(P<0.05);随着胸径增大,千年桐和华润楠的树叶生物量占比呈极显著下降趋势(P<0.01),4个树种的树枝生物量占比均呈上升趋势,树干生物量占比均呈下降趋势,根生物量占比和胸径之间均未表现出显著相关性;以胸径(D)为单一自变量的生物量模型具有较好拟合精度(平均R2=0.947);将H以D2 H形式包含在模型中,导致地上和全株生物量模型的拟合能力下降,但地下生物量拟合能力略有提升;将H以独立第二自变量包含在模型中,将增加模型的多重共线性问题;将ρ以D2ρ形式包含在模型中对单株及各组分生物量的估算精度均有所下降;将 ρ以独立第二自变量包含在模型中,能略微提高估算精度.[结论]阳生树种千年桐分配较多生物量给树干,耐荫树种中华锥分配较多生物量给枝叶,耐荫树种中华锥和华润楠的根系更发达.随着胸径的增加,4个树种的树干生物量分配比例呈下降趋势而树枝的生物量分配比例呈上升趋势.对4个树种的生物量估算,建议选用D为单一自变量的模型,不建议将H作为第二自变量包含在模型内.增加 ρ为第二自变量后仅能小幅提高模型拟合能力,建议实际应用中根据调查目的在准确性和工作难度间做出取舍.

通过实地调查,对湖南莽山国家森林公园针阔混交林的粗死木质残体(CWD)现状进行研究,以揭示莽山典型森林CWD的发生特征及分布规律,为莽山森林资源的经营与保护提供理论依据.通过在莽山针阔混交林内设置一个面积0.15 hm2样地,并将其分成15个小样方,调查分析每个小样方内CWD的输入方式、径级结构、贮存量和腐烂等级.莽山CWD的输入方式包括倒木、枯立木和枯枝,大径级倒木是CWD贮存量的主要组成部分,针阔混交林CWD的总贮存量为108.59 t·hm-2.从腐烂等级来看,CWD的腐烂等级以Ⅲ级、Ⅳ级较多,分别占其总贮存量的29.3％、42.8％,Ⅰ级、Ⅱ级腐烂程度都较少.莽山针阔混交林的CWD贮存量大于国内其他森林,且以直径30cm以上的倒木和枯立木为主,腐烂等级高,这可能与冰灾、风害的影响有关.

对比分析广东南雄小流坑-青嶂山自然保护区与城区、乡镇的空气负离子变化特征,探究森林植被对空气负离子的调控作用,为森林旅游资源开发和生态环境建设提供理论支撑.使用空气负离子仪对2019年保护区内外的空气负离子浓度进行实地对比观测和分析.研究结果表明:(1)空气负离子浓度空间分异明显,保护区内空气负离子年平均值为1194 ion·cm-3,分别是乡镇和城区的1.5倍和2.8倍;(2)保护区内空气负离子浓度的季节性变化显著,夏季最高,冬季最低,但城区空气负离子的季节性变化不显著;(3)一天之内,空气负离子浓度上午或者傍晚最高,中午最低,下午居中.森林对空气负离子具有明显的调控作用,森林质量越好,空气负离子浓度越高.

冰暴、台风等极端气候事件严重干扰了森林生态系统,导致大量落叶、断枝、断干等非正常凋落物产生,将对土壤碳库产生激发效应,然而目前对这种现象的研究仍十分匮乏.以马尾松(Pinus massoniana)、黧蒴锥(Castanopsis fissa)、浙江润楠(Machilus chekiangensis)3种南亚热带常见树种为研究对象,利用13C标记植株并采集其新鲜叶片添加至土壤表面,进行了为期110 d的室内培养实验,培养中分别测量了CO2排放量、13C丰度值以及培养前后土壤碳库的变化.结果表明,不同树种的非正常凋落物的碳排放模式相似,均表现为前期快速升高,之后波动下降,后期稳定在较低水平.其中91.39％—94.04％的碳排放过程发生在前中期(0—45 d).110 d的培养过程中,非正常凋落物分解产生的碳有67.86％—95.31％以C–CO2的形式排放到大气当中.非正常凋落物输入对土壤有机碳的激发效应主要分为3个阶段.培养前期(0—7 d)3种非正常凋落物输入均引起了土壤碳强烈的负激发效应且在短期内达到峰值,峰值分别为?50.05、?117.72、?124.08;培养中期(7—35 d)负激发效应强度逐步下降,表现为先快速下降后速率转慢;培养后期(35—110 d)碳激发效应较为平稳,不同树种之间有所差异,黧蒴锥、浙江润楠的碳激发效应逐渐转为正向,而马尾松维持负激发效应并缓慢下降至消失.经过110 d的培养,马尾松、黧蒴锥的0—5 cm层土壤有机碳显著高于对照组(P<0.05),黧蒴锥的0—5、5—10 cm层土壤的13C同位素值显著高于对照组(P<0.05).各处理组与对照组之间全氮、有效氮差异均不显著(P>0.05).非正常凋落物输入在短期内对表层土壤有机碳含量影响显著而对深层土壤没有影响,其分解产生的碳大部分以C–CO2的形式排放到大气当中.

为了分析南岭中段区域弄蝶(Hesperiidae)的物种组成、南坡与北坡的差异、不同海拔弄蝶的多样性及生态分布特点,选择南岭中段广东南岭自然保护区(南坡)和湖南莽山自然保护区(北坡)为监测区开展研究.2012—2015年共发现弄蝶83种,其中南坡73种,北坡43种,加之前人调查和记录的共有53属144种,其中东洋区占80.56％,东洋-古北区占14.58％;在中国动物地理区中,华南、西南、华中3区共有种占31.25％,仅分布于华南区占29.17％,华南区与西南区共有种占13.89％,华南区与华中区共有种占12.50％.在种的数量上,南坡高于北坡;除北坡海拔600 m外,各监测点种的数量存在年际间波动,呈现先下降后上升再下降的趋势,且优势种不相同,南坡海拔600、1100 m和北坡600 m的优势种均为旖弄蝶Isoteinon lamprospilus,而北坡1100 m的优势种为白弄蝶Abraximorpha davidii,山顶的优势种为无趾弄蝶Hasora anura;中等海拨(1000—1100 m)山地常绿阔叶林中的物种数、种群密度和各生物多样性指数,均高于低山常绿阔叶林(500—600 m)和山顶矮林(1850—1902 m),该结果符合有关生物多样性的"中间高度膨胀"假说;南北坡间各监测点相似性指数在0.095—0.465,相似性指数最大的均是海拔500 m.南岭中段弄蝶在组分上呈现热带向亚热带过渡的特点,有明显的以南岭为核心向周边扩散的现象,暗示了南岭中段可能为中国弄蝶的起源和分化中心之一.该研究结果可为林业区划、环境监测、蝶类资源的保护与可持续性开发利用等提供科学依据.

[目的]为充分了解粤北地区针阔叶混交林碳(C)、氮(N)、磷(P)、钾(K)元素在树木不同器官中的分配格局及其生态化学计量特征,以期揭示粤北地区南亚热带针阔混交林中树木不同器官的养分平衡机理及环境适应机制,为合理经营管理南亚热带森林生态系统提供科学依据.[方法]以广东南雄小流坑-青嶂山省级自然保护区的木荷、南酸枣、米槠、杉木、马尾松5个主要树种为研究对象,分析比较不同树种枝、叶、根、干的养分元素含量、生态化学计量特征及其C、N、P、K含量和计量比之间的相关关系.[结果]5个树种不同器官的N、P、K元素含量均表现为叶最高,干最低,根、枝居中;5个树种不同器官的C∶N、C∶P、C∶K均表现为干最高,叶最低,根、枝居中.5个树种叶的平均C、N、P、K含量分别为512.04、14.29、0.74、10.30 mg·g-1,且叶的N、P、K含量与其他器官存在显著差异(P＜0.05).相关性分析表明:树木具有复杂的内在协调机制.[结论]粤北针阔混交林树种不同器官的C含量较高,但N、P、K元素较缺乏,树木生长主要受P限制;米槠、南酸枣、杉木具有较高的P利用能力,且南酸枣具有更合理的养分分配格局,有利于在群落竞争中保持优势地位.

Accurate estimation of forest biomass and its growth potential could be important in assessing the mitigation potential of forest for climate change. However, severe mechanical disturbance such as stem breakage imposed significant changes to tree individuals in biomass structure, which could bring new inaccuracy to biomass estimation. In order to investigate the influence of severe mechanical disturbance on tree biomass accumulation and to construct accurate models for biomass and carbon storage estimation, this paper analyzed the relationship between tree size and biomass for China fir (Cunninghamia lanceolata (Lamb.) Hook) which suffered stem breakage from, and survived, an ice storm. The performance of independent variables diameter (D) and height (H) of China fir, were also compared in biomass estimation. The results showed that D as an independent variable was adequate in biomass estimation for China fir, and tree height was not necessary in this case. Root growth was faster in China fir which had suffered breakage in the main stem by the ice storm, than China fir which were undamaged for at least 7 years after the mechanical disturbance, which, in addition to biomass loss in stem, caused changes in the allocation pattern of the damaged trees. This suggests biomass models constructed before severe mechanical disturbance would be less suitable in application for a subsequent period, and accurate estimations of biomass and forest carbon storage would take more effort.

Extreme climate events always leave numerous fresh plant materials (FOM) in forests, thus increasing the input of carbon (C) resources to soil system. The input of exogenous C may accelerate or inhibit the decomposition of soil organic carbon (SOC), which is defined as the positive or negative priming effect (PE), respectively. However, the characteristics and microbial mechanisms of PE caused by FOM remain unknown. A 110-day in situ soil incubation experiment was conducted in a subtropical forest, with 13C-labeled fresh leaves from four native species (Castanopsis fissa, CF; Pinus massoniana, PM; Machilus chekiangensis, MC; and Castanopsis chinensis, CC) serving as the FOM respectively. We measured the CO2 effluxes derived from 13C-labeled FOM and soil, and the composition and diversity of soil bacterial and fungal communities throughout the incubation to explore the correlations between PE and microbial attributes. As a result, the PE caused by FOM inputs were negative initially but became positive after 61 d. The FOM decomposition rate was positively related to PE intensity, and there was a significant difference between coniferous and broadleaved species in the middle period of the study. More than 77% of the total C lost from FOM was emitted as CO2, indicating that FOM-C serves as an energy resource for soil microbes. The α-diversity of the bacterial community at genus-level showed significantly positive correlation with PE at 24 d, and the composition of bacterial community at OTU-level had a marked relationship with the PE between 24–110 d. The relationship between fungal community diversity and composition with PE was only observed at 7 and 110 d, respectively. This study firstly investigated the patterns of PE resulted from numerous FOM input, and the results suggested that soil bacterial community, in particular the Actinobacteria phyla, played a more important role in triggering such PEs than fungal community.

Canopy interception is an important component of the hydrological cycle of forested catchments, and is influenced by variations in the canopy structure. Extreme meteorological events can have a destructive impact on forest density and structure, and affect the rainfall partitioning by the canopies. Despite extensive investigation of throughfall and stemflow, the response of rainfall interception loss to post-disturbance vegetation recovery is still poorly understood. In this work, we examined the variations in the canopy structure and rainfall interception recovery after a destructive ice and snow storm that occurred in southern China in 2008. Rainfall partitioning into throughfall and stemflow were measured for multiple years at two damaged sites on Nanling Mountain, while the interception loss was modeled using the revised Gash model. The results showed that the vegetation leaf area index (LAD doubled from 2010 to 2014. This recovery caused the throughfall rate to decrease and the interception rate to increase. The application of the revised Gash model indicates that the vegetation canopy storage capacity (S) and vegetation cover factor (c) increased with the LAI, resulting in an increase in the interception loss and variations in its components. The interception recovery at the study plots provide a biophysical explanation for the threshold behaviors of runoff generation at catchment scale. Comparisons with canopy interception measurements from nearby undamaged secondary forests suggest that interception capacity in the study plots was not fully recovered for the first 5-7 years after the disturbance, indicating that measurements for a longer duration are needed to evaluate the interception recovery from that great disturbance.

Forest ecohydrological feedbacks complicate the threshold behaviour of stormflow response to precipitation or wetting conditions on a long-term scale (e.g. several years). In this study, the threshold behaviours in an evergreen-deciduous mixed forested headwater catchment in southern China were examined during 2009-2015, when damaged vegetation was recovering after the great 2008 Chinese ice and snowstorm. The non-uniqueness of the thresholds and the slow and rapid responses of stormflow at the outlet of the catchment in different hydro-climate datasets with different maximum values of gross precipitation (P) and sums of precipitation and antecedent soil moisture index (P + ASI) were assessed. The thresholds of P and P + ASI required to trigger stormflows (i.e. 'generation thresholds') and the transition from slow to rapid responses of stormflow (i.e. 'rise thresholds') were compared both seasonally and annually. The results indicated significant differences in the analysed datasets, highlighting the need to compare thresholds with care to avoid misinterpretation. Seasonal variations in threshold behaviours in the catchment suggested that vegetation canopy interception contributed to higher rise thresholds, and wetter conditions resulted in higher runoff sensitivity to precipitation during the growing and rainy seasons. Furthermore, the generation thresholds were higher in the dormant season, possibly due to drier soil moisture conditions in the near-channel areas. During the vegetation recovery period, the annual generation thresholds increased, however the rise thresholds did not exhibit a similar trend. The rapid stormflow response above the threshold decreased, possibly due to transpiration and interception of the recovered vegetation. However, the slow stormflow response to small rainfall events below the thresholds was higher in wetter years but lower in drier years, suggesting that the total water input dominated the stormflow response during small rainfall events. In conclusion, the seasonal and annual variations in threshold behaviours highlight that vegetation recovery and hydro-climatic conditions had a notable impact on the stormflow response.

光环境与幼树功能性状的关系对天然林的更新与演替具有重要的生态学意义.以广东南岭区域天然常绿阔叶林下不同林龄(幼龄林,中龄林,老龄林)的森林群落为研究对象,通过监测冠层结构、林下光照数据和林下幼树功能性状等指标,研究林龄梯度下其冠层结构与林下光环境之间的关系,以及林下幼树功能性状对光环境的响应.结果 表明:(1)中龄林叶面积指数显著高于幼龄林和老龄林(P＜0.05),随着林龄的增长,林冠开度和透光率逐渐下降,林龄梯度下透光率、R/FR(红光/远红光比值)、Bw/Rw(宽带蓝光/宽带红光比值)差异极显著(P＜0.001);(2)天然常绿阔叶林中透光率与光质之间极显著相关(P＜0.001),R/FR随着透光率的增加而增加,Bw/Rw随着透光率的增加而减少.(3)林下幼树功能性状在光环境之间差异显著(P＜0.05),老龄林林下幼树叶片氮含量显著高于幼龄林,而叶片重叠率显著低于幼龄林;(4)在本试验地中,R/FR和Bw/Rw的变化对林下幼树的高径比和光合作用并无显著影响,光强对同种植物不同光环境下最大净光合速率的影响较大.总体而言,林龄梯度冠层结构和光环境的差异能在一定程度上解释幼树功能性状的差异,这将有助于我们理解光环境对林下幼树更新的影响机制,同时为天然植被恢复和森林经营提供指导.

A catastrophic ice storm occurred in the spring of 2008, which severely destroyed nearly 13% of China’s forests; among them, the broad-leaved forest suffered the most extensive damage. In this study, allometric models of the evergreen broad-leaved forests damaged at different recovery stages after the disaster were established to estimate the aboveground biomass of damaged trees. Plant plots were established and surveyed in damaged forests to determine species composition and diameter distribution, and finally a sample scheme was formulated that contained 47 trees from 13 species. The destructive measurements of aboveground biomass of trees selected according to the scheme were conducted in 2008, 2010, 2012 and 2016, respectively. Undamaged trees in the same region were also selected to measure the biomass in 2010. Linear regression of logarithmic transformation of the power function form was performed using Diameter at Breast Height (DBH) as predictor to develop biomass allometric models. The results showed that the ice storm caused tree aboveground biomass loss, which caused different parameters of the tree biomass models at different recovery stages. The models have a high accuracy in predicting trunk and total aboveground biomass, with high determination coefficients (R2, 0.913~0.984, mean 0.957), and have a relatively low accuracy in predicting the biomass of branches and leaves (R2, 0.703~0.892, mean 0.784). The aboveground biomass reduced by 35.0% on average due to the ice storm, and recovered to the same level of undamaged trees in the same diameter 8 years after the disturbance. The branches and leaves recovered very fast, and the biomass of these parts exceeded that of the undamaged trees, reaching the same diameter 2 years after the disaster, indicating an over compensatory growth. The trees with a smaller diameter were mostly composed of middle and late succession species, and recovered faster than other species, indicating that the ice storm may alter the forest structure and accelerate community succession. The biomass allometric models built in this study, combined with forest inventory data, can estimate forest biomass loss and recovery after disturbance, and offer an important sense of the assessment of forest damage and the formulation of forest post-disaster management strategies.

林区公路的生态水文影响历来少受关注,道路对集水区径流的影响及其机制仍不明确.在南岭国家森林公园选取2个对比森林集水区,其一为自然状态(W1),另一个受旅游公路干扰(W2),利用各集水区2017年8月-2018年7月连续监测的降雨和流量数据,研究了林区公路对径流的影响.结果表明:(1)在W2集水区,不同雨量级的次降雨产生的快速径流量是集水区W1的1.64-3.69倍,W2的水文响应值的年平均值(12.60％)是W1(4.32％)的2.92倍;而且在相似降水条件下W2的洪峰流量远大于W1,洪峰滞后雨峰的时间比W1短;(2)基于79场(W1)和87场(W2)雨量P≥5 mm的次降雨及其径流的监测,将两集水区各次降雨过程中产生的快速径流(QF)与降雨量(P)、降雨历时(PD)、前7天降水量(AP7)、最大30 min雨强(I30)、最大60 min雨强(I60)、平均降雨强度(AHRD)和初始流量(Fi)各指标进行相关分析,两个集水区的快速径流都与降雨量、降雨历时呈极显著相关;此外W1的快速径流与I60呈极显著相关,与I30显著相关,W2的快速径流与I30和I60相关关系不显著,但与AP7呈显著相关;(3)观测期间,W2的年径流系数为0.4895,W1的年径流系数为0.4437,基流占总径流的比率(BF/R)在一年中每个月都表现为W2小于W1.林区公路修建引起了径流量、径流组分分配以及径流过程变化:林区公路明显增加集水区的快速径流量和洪峰流量并使洪峰滞后雨峰的时间缩短,导致产生快速径流的主导因素改变;显著减少了集水区的基流补给,使集水区径流中基流比例显著减少.