Diesel exhaust particulate matter (DPM), which has been clarified as a Group I carcinogenic agent, is still challenging in its detoxification due to the complex composition and toxic mechanisms. Astaxanthin (AST) is a pleiotropic small biological molecule widely used in medical and healthcare with surprising effects and applications. The present study aimed to investigate the protective effects of AST on DPM-induced injury and the underlying mechanism. Our results indicated that AST significantly suppressed the generation of phosphorylated histone H2AX (γ-H2AX, marker of DNA damage) and inflammation caused by DPM both in vitro and in vivo. Mechanistically, AST prevented the endocytosis and intracellular accumulation of DPM via regulating the stability and fluidity of plasma membranes. Moreover, the oxidative stress elicited by DPM in cells could also be effectively inhibited by AST, together with protecting the structure and function of mitochondria. These investigations provided clear evidence that AST notably reduced DPM invasion and intracellular accumulation by modulating the membrane-endocytotic pathway, which eventually reduced intracellular oxidative stress caused by DPM. Our data might provide a novel clue for curing and treating the harmful effects of particulate matter.

北京主要河流河岸带实施平原造林工程后,对河岸带植被类型及土壤造成不同程度影响.研究河岸带原有及重建植被类型土壤生态化学计量特征,对河岸生态系统土壤碳氮磷平衡及固碳潜力提升提供科学依据.选取北京温榆河昌平段岸边原有植被类型3种样地(乔木林、乔灌林及草地),重建植被类型2种样地(乔木林与灌木林),共15个样方,采集3层(0—10,10—20,20—30 cm)土壤样品,分析并计算碳(C)、氮(N)和磷(P)含量及计量比.结果表明:原有与重建植被类型的土壤有机碳(SOC)、全氮(TN)、全磷(TP)含量分别为3.810～10.320,0.223～0.700,0.551～0.692 g/kg,C/N、N/P、C/P分别为11.592～25.373,0.373～1.022,5.662～15.493;SOC与TN均在表层聚集,且同N/P、C/P一样表现出随土层深度增加而减少趋势,C/N反之,TP受土层深度影响较小;原有植被类型(乔木林)土壤SOC和TN均高于其他植被类型,在10—20,20—30 cm土层间C/N、C/P均显著低于其他植被类型(P<0.05);原有植被类型(草地)在0—10 cm土层间N/P最低;重建植被类型(乔木林)土壤TP含量显著低于其他植被类型;重建植被类型(灌木林)C/N显著高于其他植被类型.研究结果揭示了研究区土壤N素为植物生长的限制元素,乔木、乔灌林下土壤有机质释放更多,P有效性更高,固碳潜力强;重建植被类型有机质矿化较慢,固磷能力更强.因而,建议温榆河河岸带采用乔木纯林和乔灌混交模式来积累土壤有机质,提高河岸带生态系统土壤质量及固碳潜力.

近年来再生水逐渐成为城市景观河流的主要用水来源,但再生水含有较高氮元素,容易造成水体与地下水污染.河床底泥对NO-3-N有一定的截留与去除作用,本实验通过河槽装置模拟潮白河河床,探究低、中、高3种NO-3-N质量浓度水平下河槽系统中底泥对NO-3-N的去除效果.结果 表明:水体中NO-3-N质量浓度为5、10、20 mg·L-1时NO-3-N去除率分别为67.8％、63.0％、55.0％.河槽10 cm处和下部70 cm处对NO-3-N去除效果较好.底层排出水中pH与NO-3-N质量浓度相关性较强,底泥中50 cm与70 cm处反硝化作用强度与溶解氧质量浓度紧密相关;随着温度降低,溶解氧质量浓度升高,反硝化作用减弱,NO-3-N去除效果变差.底泥中NO-3-N的去除主要通过土壤淋溶作用、同化作用、反硝化作用与异化还原作用等共同作用;部分氮素以同化作用形成的有机氮和异化还原作用形成的NH+4-N留存于底泥中.研究表明,河床底泥对再生水河道具有一定的净化效果.

文章利用碳、氮稳定同位素技术对江湖阻隔典型湖泊-保安湖的食物网结构进行了研究.结果表明保安湖中鱼类消费者的主要营养级范围为2.1—3.3,在调查到的16种鱼类中,顶级肉食性鱼类种类很少,杂食性鱼类的种类最多.保安湖食物网主要由两条营养传递途径构成,即由POM、浮游植物为主要食物源的浮游牧食链与沉积物为主要食物源的底栖食物链.POM、浮游植物、浮游动物和底栖动物是保安湖水域食物网中鱼类的主要食物来源,其次是沉积物中的碎屑和水生植物等.此外,从基于理论食性数据的食物网与BIMM模型预测的食物网结构可以看出,从POM、浮游植物、浮游动物到杂食性鱼类的浮游牧食链在整个食物网中具有主导性,而从水生植物、沉积物和底栖动物到杂食性鱼类的底栖食物链相对重要性较低.

[目的]研究不同温度制备生物炭与秸秆配施对设施菜地土壤有机碳矿化特征及土壤理化性质的影响.[方法]以北京郊区设施菜地土壤为研究对象,进行室内矿化培养试验.[结果]生物炭与秸秆配施显著提高土壤有机碳矿化速率和累积矿化量,而单施生物炭对两者影响较小.添加300℃生物炭处理的土壤有机碳累积矿化量比添加600℃生物炭的处理高2.6％～17.6％,土壤有机碳累积矿化量随着秸秆添加量的增加而增大.生物炭的添加降低土壤有机碳的相对矿化潜力,额外添加等量秸秆也未能完全抵消生物炭对土壤有机碳相对矿化潜力的抑制作用.单施生物炭和生物炭与秸秆配施均显著提高土壤pH值和电导率.与单施生物炭相比,生物炭与秸秆配施对土壤有机质、碱解氮、有效磷含量的提升效果更为显著.[结论]施用生物炭对提高设施土壤有机质含量和碳库稳定性、促进固碳减排具有重要意义.而生物炭与秸秆配施不仅能够发挥生物炭的固碳功能,也能够提供更多的有效养分,更有利于改善设施土壤质量和促进土壤养分平衡.

采用通气法对设施菠菜和黄瓜在施用生物质炭与翻耕措施下土壤氨气(NH3)排放进行观测,探索设施菜地NH3减排的有效途径.观测表明,设施菠菜与黄瓜土壤NH3排放主要发生在施肥后一周内.在施化肥氮总量300 kg/hm2条件下,设施菠菜不施生物质炭和表施生物质炭处理的NH3排放量分别占总氮投入量的8.00％和10.15％,而翻耕措施分别降低各处理NH3排放38.34％和56.22％(P<0.05).在施化肥氮总量600 kg/hm2条件下,设施黄瓜不施生物质炭和表施生物质炭的NH3排放量分别占总氮投入量的3.03％和4.80％,而翻耕措施分别降低各处理NH3排放9.45％和37.61％.设施菜地表施生物质炭增加土壤NH3排放,其中菠菜和黄瓜单位产量的NH3排放量分别增加52.58％和78.17％(P<0.05).根据设施菜地NH3排放特点和不同处理的减排效果,建议减少基肥投入以控制NH3排放,并利用翻耕措施消除表施生物质炭对NH3排放的促进效应.

Soil organic carbon (SOC) is an important component of the carbon (C) cycle in forest ecosystems, and is largely influenced by tree species. Leaf litter originated from different vegetations introduce organic materials into soil with different quantities and qualities, and influence the formation and stability of soil C pool. We present a study on the influence of tree species on SOC stability under three temperate forests: pine (Pinus tabuliformis Carr.), larch (Larix principis-rupprechtii Mayr.) and birch (Betula dahurica Pall.) in the Baihua Mountain Reserve. The SOC and permanganate oxidizable C (POXC) concentrations in the 0–5, 5–10, 10–20 and 20–30 cm soil layers were determined. The SOC stability was evaluated by analyzing the chemical composition of SOC and the distribution of organic C in soil particle-size fractions under different tree species. The birch forest had significantly higher SOC and POXC concentrations than pine and larch in all the four soil layers. These differences might be partly related to the altitude, and also caused by the differences in litter characteristics between birch and the two coniferous species. The organic C was enriched in clay-sized fraction in birch forest soil, but showed higher concentrations in coarse sand fraction (2000-250 μm) under pine, suggesting a higher potential of birch forest for C accumulation in stable SOC pools. The chemical composition of SOC was determined by solid-state 13C nuclear magnetic resonance (NMR) spectra and showed that the birch forest soil had higher alkyl C/O-alkyl C, aromatic C/O-alkyl C and hydrophobic C/hydrophilic C ratios than pine and larch forest soils in the top 5 cm soil layer, reflecting a more recalcitrant SOC composition under birch than under pine and larch. We concluded that the birch forest could not only increase SOC concentration in mineral soils but also had a higher potential to accumulate C in stable soil C pools, and thus is more beneficial to SOC stabilization than the pine and larch forests. This study highlights that future strategy of tree species selection needs to consider the potential effects of tree species on the stability in addition to the concentration of SOC.

准确评估及对比分析内蒙古呼伦贝尔海拉尔区谢尔塔拉镇(农牧区)与陈巴尔虎旗西乌珠尔苏木(纯牧区)家庭牧场肉羊温室气体排放,以寻求养殖业发展的有效减排措施.在《2006 IPCC国家温室气体清单指南》基础上提出一套较为完整的肉羊温室气体计算方法,结合实地调研资料对农牧区和纯牧区共12个家庭牧场肉羊生产过程中的温室气体排放量进行比较研究.以肉羊出栏时1kg活体质量为功能单位,结果表明,农牧区出栏1kg肉羊活体质量的温室气体排放强度(以二氧化碳当量CO2-eq计)为26.74 kg,纯牧区为13.88 kg,前者为后者排放强度的1.92倍.在肉羊温室气体排放功能单位上,肠道甲烷排放量最多,分别为19.81 kg和10.94 kg,粪便管理系统排放量分别为5.12 kg和2.86 kg,饲料粮种植运输环节排放量分别为1.50 kg和1.62 kg.在农牧区与纯牧区调研牧户的年温室气体排放总量上,肠道甲烷排放为最大排放源,分别为58.51 t和198.09 t;其次是粪便管理系统排放,排放总量分别为14.73 t和52.39 t;饲料粮种植运输环节排放量分别为2.98 t和22.45 t.本研究表明农牧区出栏1kg的肉羊活体质量温室气体排放强度高于纯牧区,两区域在肠道甲烷、粪便管理系统、打草柴油消耗与农资运输环节中差异显著,其中肠道甲烷排放在总排放量中占据主导地位.

新型污染物1,4-二（口恶）烷广泛分布于地表水、地下水和饮用水环境中。常规水处理手段对1,4-二（口恶）烷难以奏效,因而其污染处理技术成为了关注的热点。本文主要针对1,4-二（口恶）烷污染的处理方法进行了综述。首先对1,4-二（口恶）烷的性质及分布特征进行了总结,比较了国内外已有的污染调查状况和控制标准,然后重点从物理、化学和生物法三个方面介绍了近年来1,4-二（口恶）烷污染处理技术的最新研究进展,且分析了不同技术的作用机制、优缺点及可行性,并对不同技术的处理效率进行了归纳总结。文中特别指出了生物修复的难题,即氯代烃、重金属对微生物降解1,4-二（口恶）烷的抑制作用和机理及改进修复技术,最后对今后的研究方向进行了展望。

玉米和稻谷是南方地区重要的饲料原料来源.本研究采用LI-6800便携式光合作用测定系统观测了温度和CO2浓度对长江中游平原水稻和玉米扬花期功能叶片光合参数的影响.结果表明:玉米扬花期功能叶片净光合速率对温度升高的敏感性高于水稻.温度升高提高了水稻功能叶片的光合速率.CO2浓度增加提高了扬花期水稻和玉米的最大光合速率.当温度条件相同时,在高CO2浓度条件下水稻比玉米更容易维持较高的光合速率.玉米功能叶片最大电子传递速率(Jmax)与最大羧化速率(Vcmax)的比值(Jmax/Vcmax)随温度升高而显著下降(P<0.05),而水稻Jmax/Vcmax值对温度升高无显著变化.温度升高与CO2浓度增加均可降低两种作物的叶片气孔导度和植物蒸腾速率.本研究发现,玉米功能叶光合参数及生化参数对高温环境较为敏感,即玉米的光合酶活性和光合能力比水稻更容易受到温度升高的抑制作用.建议未来应重视气温升高对玉米饲料资源带来的不利影响,在畜禽养殖中合理调整饲料原料供给结构,适当将稻谷作为饲料原料的替代来源之一,可以抑制因玉米价格上涨造成的饲养成本攀升,提高养殖效益,为新形势下畜牧业发展探索一条高效、可持续的发展道路,提升畜牧业发展的竞争力.

针对两相环路热虹吸管中出现的间歇沸腾不稳定现象,分别以R134a、水和无水乙醇作为工质,通过流场可视化实验观测,探究了间歇沸腾出现的条件及其对环路传热特性的影响.实验结果表明,在中等充液率和中等加热热流密度条件下更容易发生间歇沸腾现象;流型的周期性变化引起环路内部压力和温度波动,同时会增加环路的均温性;流型变化和波动特性因工质不同而有所差别,水作为工质时,波动周期更长,流型变化及压力波动更复杂.

[目的]设施菜地存在施肥量过大、肥料利用率低、环境污染等问题.通过对天津市设施菜地施肥现状调查,明确设施菜地施肥现状和存在问题,为制定科学合理的施肥方案提供依据.[方法]本研究对天津市193个设施蔬菜地块施肥现状展开调查,明确设施菜地施肥特征,估算肥料总养分和化肥养分减施潜力.[结果]天津市日光温室平均养分施用总量为N 775.6 kg/hm2、P2O5715.5 kg/hm2和K2O 524.9 kg/hm2,显著大于塑料大棚对应养分平均施用总量N 670.9 kg/hm2、P2O5584.5 kg/hm2和K2O 425.3 kg/hm2(P＜ 0.05).有机肥是设施菜地养分的主要来源,对日光温室和塑料大棚N、P2O5和K2O各自施用总量的贡献均超过50％.日光温室和塑料大棚中,化肥对磷(P2O5)施用量的贡献分别为44.2％和48.8％.从养分施用方法看,N、P2O5和K2O基施比例日光温室分别为79.4％、80.2％和73.5％,塑料大棚分别为70.2％、78.2％和67.4％,P2O5基施比例大于N和K2O.日光温室和塑料大棚平均养分施用比例(N:P2O5:K2O)分别为1.00:0.92:0.69和1.00:0.87:0.63.相比推荐施肥量,天津市设施蔬菜N和P2O5普遍施用过量,甘蓝和白菜K2O投入不足.设施菜地总养分(N+P2O5+ K2O)减施潜力在31.5％～65.0％,化肥养分减施潜力在22.4％～66.6％.[结论]天津市设施菜地养分以基施为主,其中化肥基施比例偏高,追肥养分比例过低,养分总量过量施用现象普遍.设施菜地基施化肥和追肥中P2O5比例偏高,养分结构不合理.主要设施蔬菜中,茄子、番茄和芹菜的N和P2O5施用总量远超过各自推荐施肥量,化肥养分减施潜力较大,是设施蔬菜肥料减施关注的重点.

[目的]旨在探讨北京低山区不同植被凋落物对土壤有机碳矿化特征及土壤酶活性的影响.[方法]采集北京低山区典型人工林植被油松、侧柏和栓皮栎凋落物,采用室内矿化培养试验,通过测定土壤有机碳矿化速率和累积矿化量,以及土壤中易氧化有机碳含量和β-葡萄糖苷酶、碱性磷酸酶活性,分析不同凋落物种类及添加量下土壤有机碳矿化特征的差异,并分析对土壤有机碳组分和酶活性的影响.[结果]添加不同植被凋落物的土壤有机碳矿化速率和累积矿化量存在显著差异,在2.5 g/kg和5.0 g/kg添加量下,土壤有机碳矿化速率均表现为侧柏(52.0和104.0 mg/ (kg·d))＞栓皮栎(46.0和82.0 mg/ (kg·d))＞油松(38.0和74.0 mg/(kg·d)),且随着凋落物添加量的增加而增大.有机碳累积矿化量与矿化速率的规律一致.通过一级动力学方程进行拟合,侧柏处理的土壤有机碳潜在可矿化量最大,可达1 549.4 mg/kg,其次为栓皮栎,油松最小.矿化培养45 d后,添加不同凋落物的处理间土壤有机碳含量无显著差异,但油松处理的易氧化有机碳含量、β-葡萄糖苷酶活性和碱性磷酸酶活性均显著高于侧柏和栓皮栎处理,易氧化有机碳比例和土壤酶活性与土壤有机碳潜在可矿化量间均无显著相关性.[结论]侧柏凋落物具有相对更高的矿化潜力,而油松凋落物则更有利于土壤中有机碳的积累.

"地质与地貌学"是一门理论性和实践性很强的课程,是农业资源与环境专业必修的一门专业基础课.采用互动式教学有效提高该课程学生的考试成绩.互动式教学方法是"地质与地貌学"课程教学模式改革的一种新途径,对本专业教学模式改革具有积极的意义.

[目的]对天然草场修复过程中的经济环境综合效益进行评估.[方法]基于全生命周期分析(LCA)方法对内蒙古呼伦贝尔市谢尔塔拉牧场奶牛集约化养殖-牲畜粪便处理(包括菌剂发酵有机肥、蚯蚓养殖生成有机肥和蘑菇种植3种模式),利用谢尔塔拉农场奶牛集约化养殖、牲畜粪便处理利用、天然草场改良数据和当地畜牧生产经营物料投入数据相结合,建立不同养殖模式下牛奶生产的生命周期清单,从畜牧生产全生命周期的角度对牲畜饲养、粪便处理利用和草场修复这整个草原畜牧生产循环过程中每生产1 t标准牛奶(FPCM)的资源环境综合成本(温室气体排放、土地占用、耗水量和不可再生能源消耗)和总体经济效益进行定量分析.[结果]牧户散养奶牛和集约化奶牛养殖场在出售牲畜和牛奶方面产生的毛收益分摊在每头成年母牛上分别为0.89和2.11万元,如扣除经营成本,两种乳牛饲养模式下每头成年母牛产生的净收益分别为0.42万元(牧户散养)和0.41万元(集约化养殖).此外集约化养殖场每生产1 t FPCM造成的环境影响为:占用草场1.19 hm2、占用耕地0.15 hm2、耗水216.47 t、消耗化石燃料1 944.19 MJ、排放温室气体0.73 t二氧化碳当量(CO2eq).当地散养牧户生产牛奶除去草场占用面积(3.25 hm2)外,造成的环境影响(占用耕地0.04 hm2、耗水70.70 t、消耗化石燃料892.80MJ、排放温室气体0.55 t CO2eq)均小于集约化奶牛养殖场.开展天然打草场改良可显著增加每公顷草地牧草产出(增幅68.57％)和收益(增长10.71％),改良后生产1 t FPCM可降低40.50％的草场占用面积.但改良中施肥和燃料消耗的增加会造成温室气体排放(增加17.70倍)、燃料消耗(增加2.10倍)等环境问题.在牲畜粪便处理利用技术应用方面,集约化养殖场产生的牛粪通过发酵有机肥、蚯蚓处理牛粪和蘑菇种植等处理利用方式,在解决牲畜饲养中粪便污染问题的同时,创造的净收益相当于生产牛奶净收益的5％-12％,整体看带来的环境影响相对较少.[结论]集约化养殖场在提高草原利用效率方面优势明显,在提升饲料能量转化效率、提升牛奶产量和质量方面具有很大的潜力,但是会增加苜蓿、燕麦等高蛋白饲草料的种植面积,在控制牛奶生产中的温室气体排放、水资源和能源消耗等方面会产生不利影响.此外,天然打草场改良和牲畜粪便处理利用技术在呼伦贝尔当地畜牧产业中具有较大的应用潜力.

为初步确定氨基酸与N-亚硝胺之间的转化关系,本研究以精瘦肉为原料,在肉丸中分别添加1 mg/kg赖氨酸、精氨酸、丙氨酸、脯氨酸、酪氨酸、缬氨酸,低温(4℃)贮藏9d,利用气相色谱-串联质谱联用(GC-MS/MS)方法定期测定内丸中N-亚硝胺含量,探究氨基酸与N-亚硝胺间的转化关系,并分析五味子对N-亚硝胺的产生以及外源氨基酸与N-亚硝胺之间关系的影响.结果 表明,肉丸中检出N-亚硝基二甲胺(NDMA)、N-亚硝基哌啶(NPIP)、N-亚硝基吡咯烷(NPYR)、N-亚硝基二正丁胺(NDBA)、N-亚硝基二苯胺(NDPHA)五种N-亚硝胺.精氨酸、脯氨酸可促进N-二甲基亚硝胺(NDMA)、N-亚硝基二正丁胺(NDBA)的生成,其中精氨酸的添加使NDMA含量最高增加了73.18％,脯氨酸的添加使NDBA含量最高增加了156.18％;同时发现五味子使添加精氨酸的NDMA含量最高降低了28.37％,使添加脯氨酸的NDBA含量最大降幅达到29.47％,NPIP含量最大降幅达到48.62％.综上,精氨酸可提高肉制品中NDMA的含量,脯氨酸可提高NDBA的含量;五味子的添加总体上降低了NPIP含量,但差异不显著;五味子对添加精氨酸的NDMA含量有降低作用,同时对添加脯氨酸的NDBA含量也有降低作用.

The use of bioaugmented zeolite (bio-zeolite) can be an effective technology for irreversibly removing recalcitrant organic pollutants in aqueous mixtures. Removal of 1,4-dioxane by a bio-zeolite (Pseudonocardia dioxanivorans CB1190-bioaugmented ZSM-5) in the presence of several chlorinated volatile organic compounds (CVOCs) was superior to removal by adsorption using abiotic zeolite. Mixtures containing 1,1-dichloroethene (1,1-DCE) were an exception, which completely inhibited the bio-zeolite system. Specific adsorption characteristics were studied using adsorption isotherms in single-solute and bisolute systems accompanied by Polanyi theory-based Dubinin-Astakhov (DA) modeling. Adsorption behavior was examined using characteristic energy (E-a/H) from modified DA models and molecular dynamics simulations. While the tight-fit of 1,4-dioxane in the hydrophobic channels of ZSM-5 appears to drive 1,4-dioxane adsorption, the greater hydrophobicity of trichloroethene and cis-1,2-dichloroethene cause them have a greater affinity over 1,4-dioxane for adsorption sites on the zeolite. 1,4-Dioxane was desorbed and displaced by CVOCs except 1,1-DCE because of its low E-a/H value, explaining why bio-zeolite only biodegraded 1,4-dioxane in 1,1-DCE-free CVOC mixtures. Understanding the adsorption mechanisms of solutes in complex mixtures is crucial for the implementation of sorption-based treatment technologies for the removal of complex contaminant mixtures from aquatic environments.

[Objective] The aim of this study is to investigate the soil erosion degree in the Three Gorges Reservoir area in order to provide the basis for regional soil erosion control.[Methods] The revised universal soil loss equation (RUSLE) model was used in conjunction with MODIS-NDVI data,DEM elevation data and land use classification data to evaluate the spatial distribution of soil erosion quantitatively in Three Gorges Reservoir area from 2000 to 2010.[Results] ① Soil erosion in Three Gorges Reservoir area was severe except for the western regions during the period from 2000 to 2010.Soil erosion in Yangtze River was dominated by severe and extreme intensity erosion.② Soil erosion in Three Gorges Reservoir area was improved from 2000 to 2010,and the area of intensive soil erosion was decreased from 1.71×106 hm2 in 2000 to 6.82×105 hm2 in 2010.Average soil erosion modulus decreased from 36.75 t/(hm2 · a) in 2000 to 22.79 t/(hm2 · a) in 2010.③ After years of erosion control,the area of intensive,severe and the extremely intensive soil erosion decreased,while the area of mild and moderate soil erosion increased.[Conclusion] Mild and moderate intensity soil erosion control need to be enhanced in the study area.

To study the temporal and spatial distribution characteristics of nitrogen and phosphorus pollution loads from agricultural nonpoint sources and analyze the main agricultural pollution sources and key control regions in the Three Gorges Reservoir Area(TGRA)of Hubei Province, the improved export coefficient model combined with the loss coefficient method was applied. This was based on agricultural data from 1991 to 2014 to estimate total nitrogen(TN)and total phosphorus(TP)pollution loads and emission intensities from different sources(rural life, livestock breeding, and planting)and different districts(Yiling, Zigui, Xingshan, and Badong). Spatial and temporal distribution characteristics were analyzed at the same time. The results showed that from 1991 to 2014, the annual average TN pollution load was 2 132.10 t·a-1, the annual average TP pollution load was 222.64 t·a-1, and the annual average TN emission intensities was 1.85 kg·hm-2·a-1, the annual average TP emission intensities was 0.19 kg·hm-2·a-1. Before 2006, TN and TP pollution loads reduced year by year, and then slowly increased. Compared with 1991, the annual TN pollution loads in 2014 decreased by 4.22% and the annual TP pollution loadsincreased by 12.30%.Dry land and rural population were the main sources of TN pollution loads,while dry land and pig raising were the main sources of TP pollution loads.Badong was the major source of TN and TP pollution loads spatially, followed by Yiling.Based on the spatial distribution of emission intensity,Badong had the highest emission intensity,followed by Zigui.The study found that farmland plant-ing and livestock breeding were the main sources of TN and TP pollution loads,Badong was the key control region of agricultural non-point source pollution,and prevention and control efforts for agricultural non-point source pollution at TGRA of Hubei Province are still required.

[Objective] This study aimed to investigate the adsorption capacity of atmospheric particulate matter (PM) including PM10 and PM2.5 per unit leaf area among different tree species,in order to select the tree species with great adsorption capacity,providing reference for reducing air pollution.[Method]Seven common tree species in Beijing Tongzhou Grand Canal Forest Park were used as study objects..Using aerosol generator (QRJZFSQ-I),the PM adsorption amount per unit leaf area in the natural state was measured,and the leaf surface micromorphological characteristics was analyzed.[Results] For the tree species studied,the adsorption amount of PM2.5 was lower than PM10.Among these seven tree species,white poplar and elm presented the lowest adsorption amounts per unit leaf area,which of cypress and pine were the highest.[Conclusion]The tree species whose leaves are rough with high stoma density and large stomatal aperture have strong PM adsorption capacities.On the contrary,since the smooth leaves with low stoma density,small stomatal aperture or special hydrophobic structure are difficult to adhere PM the PM adsorption capacities of these tree species are weak.