水位梯度对小叶章湿地土壤微生物活性的影响

通过3 a野外控制试验,研究了不同水位梯度(-10~30 cm)条件下,小叶章湿地植物地上生物量和0~15 cm以及15~50 cm土壤总有机碳(TOC)、微生物量碳(MBC)、基础呼吸(BR)、微生物商(Cmic/Corg)、代谢商(qCO2)的变化规律.结果表明,不同水位条件下植物地上生物量差异显著(p0.05),积水水位10 cm的植物地上生物量最高,且积水水位0~20 cm保持较高的生产力;积水水位变化对土壤TOC、MBC、BR、Cmic/Corg、qCO2影响显著(p0.05).土壤TOC和BR对积水水位变化的响应趋势一致,0~15 cm土壤TOC和BR在零积水水位最高;15~50 cm土壤TOC和BR随着积水水位的升高而降低,与土壤MBC和Cmic/Corg的变化趋势相同,其中MBC变化最为明显;而qCO2随着积水水位的增加而增大.随着积水水位的增加,土壤微生物群落发生改变和土壤微生物活性降低,其中积水水位30 cm的土壤微生物活性最低,对有机碳的累积与分解过程产生影响.     

三江平原不同类型小叶章湿地土壤细菌群落功能多样性

为全面了解三江平原小叶章湿地土壤细菌功能多样性的变化规律,采用Biolog-ECO微平板法对三江平原内不同类型小叶章湿地(草甸化小叶章湿地、沼泽化草甸小叶章湿地和沼泽化小叶章湿地)的土壤细菌群落功能多样性变化规律和特点进行分析.结果表明:不同类型小叶章湿地土壤理化性质差异显著(P<0.05).土壤细菌群落平均颜色变化率(AWCD)随培养时间的延长而增加,不同类型湿地土壤细菌群落代谢活性表现为草甸化小叶章湿地>沼泽化草甸小叶章湿地>沼泽化小叶章湿地;土壤细菌群落多样性之间差异显著(P<0.05),草甸小叶章湿地土壤微生物的Shannon-Wiener多样性指数和McIntosh指数最高,分别为3.30和64.03;沼泽化草甸小叶章湿地次之,分别为3.23和60.63;沼泽化小叶章湿地最低,分别为3.19和54.21.Shannon-Wiener多样性指数和McIntosh指数与平均颜色变化率变化规律一致,说明土壤细菌群落结构受到土壤理化性质的影响,并且随着土壤含水量的升高,土壤细菌群落的平均颜色变化率和多样性均呈下降趋势.土壤细菌群落对不同碳源的利用强度上存在明显差异,其中对碳水化合物类、氨基酸类碳源的利用强度差异不大(P>0.05),但是对羧酸类、胺类、酚酸类、多聚物类碳源的利用强度差异显著(P<0.05).主成分分析(PCA)表明,两个主成分累计贡献率为80%,能够很好地解释不同湿地土壤细菌在碳源利用上有明显的空间分异这一现象.碳水化合物类碳源对土壤细菌群落多样性的影响最高,其次是氨基酸类和羧酸类碳源.研究显示,土壤理化性质及植被群落组成是影响小叶章湿地土壤细菌群落组成和功能活性的重要因素.      

茂兰保护区小生境土壤微生物活性研究

以茂兰国家级自然保护区内三种植被（原生林、次生林、灌木林）下的土壤为研究对象,探讨了小生境土壤微生物数量、微生物量碳（BC）、微生物量氮（BN）、微生物熵（qSMBC）、基础呼吸及代谢熵（qCO2）的变化特征。结果表明：微生物数量、BC、BN、基础呼吸、qSMBC基本呈现石沟〉土面的趋势,qCO2则表现为土面〉石沟,即...     

不同水分条件沼泽湿地土壤轻组有机碳与微生物活性动态

通过野外实验与室内分析,对三江平原生长季内毛果苔草(Carex lasiocapa)沼泽湿地生物量及0~20cm土壤不同有机碳组分进行观测,分析了不同水分条件下毛果苔草湿地土壤轻组有机碳(LFOC)与微生物量碳(MBC)的变化动态.结果表明,随水位增加毛果苔草群落地上生物量积累明显,与10~20cm积水条件相比,17~30cm水位状况下湿地土壤具有较高的轻组有机质含量与比例.生长季初期冻融过程提高了土壤轻组分(LF)有机碳含量与LFOC含量,之后随植物生长毛果苔草沼泽湿地土壤重组有机碳(HFOC)含量增长快于LFOC,说明毛果苔草沼泽湿地土壤具有较高的重组有机质持有能力.此外不同水位条件下毛果苔草沼泽湿地微生物活性受到土壤有机碳含量影响不同,低水位条件下微生物量碳与SOC呈显著正相关关系(R2=0.859),17~30cm水位条件下二者关系不显著,并且高水位毛果苔草沼泽湿地具有较低的MBC与微生物熵,表明该条件下土壤碳库具有较高的稳定性.     

三江平原典型湿地类型土壤微生物特征与土壤养分的研究

为探讨不同湿地类型土壤微生物数量和酶活性的分布特征及其与土壤养分的关系,本研究选择了三江平原洪河湿地保护区4种典型湿地类型(小叶章+沼柳湿地、小叶章湿地、毛苔草湿地和芦苇湿地)的土壤为研究对象.结果表明4种湿地类型在0~30 cm土层内:1土壤有机碳、全氮和全磷均随土层深度的增加而减少,速效钾、速效磷和速效氮则未表现出有规律的变化,且不同湿地类型土壤养分含量差异显著.2土壤微生物数量为细菌放线菌真菌,3种微生物菌落数量均随土层深度的增加而减少.土壤微生物总数量以小叶章湿地最多,毛苔草湿地最少.3土壤蔗糖酶和纤维素酶活性均随土层深度的增加而减少,而土壤过氧化氢酶活性未表现出有规律的变化.小叶章+沼柳湿地和小叶章湿地中3种酶活性显著性高于毛苔草湿地和芦苇湿地(P0.05).4相关性分析表明,土壤细菌、真菌和纤维素酶与土壤养分各指标均呈极显著或显著正相关,放线菌和蔗糖酶与速效钾、过氧化氢酶与速效钾、速效磷无显著相关性关系.因此,土壤微生物和酶活性是反映土壤养分状况的重要指标.     

三江平原不同退化阶段小叶章湿地土壤真菌群落结构组成变化

为了了解三江平原小叶章湿地真菌群落结构及多样性变化,探讨湿地水分下降对真菌群落结构的影响.本研究采用高通量测序技术,分析和比较了黑龙江省科学院自然与生态研究所三江平原野外试验研究站内3个不同退化阶段小叶章生态类型湿地真菌群落结构多样性,探讨真菌群落改变的原因.结果表明,从小叶章沼泽湿地(w0)→小叶章沼泽化草甸湿地(w1)→小叶章草甸湿地(w2)的变化,土壤Shannon-Wiener指数(H)呈现出逐步上升的规律,即:w0w1w2.序列比对结果显示,不同小叶章湿地土壤真菌分别属于子囊菌(Ascomycota)、担子菌(Basidiomycota)、壶菌(Chytridiomycota)、未知菌(Fungi_unclassified)、接合菌(Zygomycota)这5个真菌类群,优势菌门为未知菌门(75.12%)、子囊菌门(56.56%)、担子菌门(72.65%).而且Heatmap分析也显示沼泽化草甸湿地和草甸湿地的真菌群落结构和组成比较接近.真菌群落结构受到了土壤养分以及植物组成等影响,其中土壤养分解释贡献率达88.62%,植物组成解释贡献率达到9.85%.三江平原小叶章湿地不同退化阶段湿地真菌群落结构存在较大差异,土壤水分因子对真菌多样性影响较大.这为研究三江平原湿地退化后的真菌结构多样性及空间异质性提供了科学依据.     

三江平原小叶章湿地H2S和COS排放动态

利用静态箱/气相色谱法,观测了生长季(5～9月)三江平原小叶章沼泽化草甸H2S和COS的释放动态,结果表明,H2S、COS的排放通量具有季节和日变化规律,小叶章沼泽化草甸H2S的平均释放通量为0.34μg·(m2·h)-1,COS的平均释放通量为-0.29μg·(m2·h)-1;在生长季,小叶章沼泽化草甸表现为H2S的源,COS的汇小叶章的生长过程对H2S、COS的排放影响显著,在小叶章生长旺盛期,H2S出现排放峰值,COS出现吸收高峰,H2S和COS的释放通量呈负相关.     

铬污染对土壤环境质量生物特征指标的影响研究

土壤微生物生物量碳、微生物生物量氮、微生物熵、代谢熵、土壤酶活性等是表征土壤质量的重要生物学指标,以辽宁省沈阳市新城子铬渣堆存区附近土壤为研究对象进行了土壤生物学指标的测定。污染土壤的重金属元素主要是铬,对土壤的脲酶和过氧化氢酶活性具有不同程度的抑制作用,有效铬与微生物量氮、微生物熵均呈显著负相关,而与代谢熵呈显著正相关。     

模拟氮沉降对三江平原小叶章湿地土壤微生物碳源利用能力的影响

大气氮沉降会对湿地土壤微生物的结构和功能产生显著影响,因此研究不同浓度氮沉降对三江平原小叶章湿地土壤微生物碳源利用能力的影响,对于保护和利用湿地生态系统具有重要意义.采用Biolog-Eco技术探究了连续5 a模拟氮沉降对小叶章湿地土壤微生物碳源利用能力的影响.结果表明：①长期的氮素施加会显著改变小叶章湿地土壤含水量（SMC）、pH、硝态氮（NO₃^-）、铵态氮（NH₄⁺）、溶解性有机碳（DOC）和总氮（TN）的含量（P<0.05）;②土壤微生物的平均颜色变化率（AWCD）呈现的规律为：对照（CK）>高氮（HN）>低氮（LN）.低氮处理显著降低了土壤微生物香农（Shannon）指数（P<0.05）,高氮处理显著降低了土壤微生物皮卢（Pielou）指数（P<0.05）.③不同氮浓度下土壤微生物碳源利用能力显著不同,其中低氮处理显著抑制了土壤微生物对糖类、醇类、胺类和酸类的利用强度（P<0.05）;高氮处理显著促进了微生物对酯类的利用,但高氮使土壤微生物对糖类、胺类和酸类碳源产生抑制作用（P<0.05）.④冗余分析显示,NH₄⁺、DOC和pH是影响三江平原小叶章湿地土壤微生物碳代谢能力的主要环境因子.长期氮沉降会导致土壤微生物功能多样性的降低,有关碳源底物利用的微生物活性也明显降低,并且微生物对单一碳源底物的利用能力也发生改变.     

不同水分条件下小叶章湿地表土有机碳及活性有机碳组分季节动态

通过野外试验与室内分析,考察了三江平原生长季内不同水分条件小叶章(Calamagrostis anguatifolia)湿地表层0～20cm土壤有机碳(SOC)、轻组有机碳(LFOC)与微生物生物量碳(MBC)的季节变化动态.结果表明,不同水分条件小叶章湿地表土SOC及各组分含量季节变化明显.季节性积水条件对表土活性有...     

Sulfur cycle in the typical meadow Calamagrostis angustifolia wetland ecosystem in the Sanjiang Plain, Northeast China

The sulfur cycle and its compartmental distribution within an atmosphere-plant-soil system was studied using a compartment model in the typical meadow Calamagrostis angustifolia wetland in the Sanjiang Plain Northeast China. The results showed that in the typical meadow C. angustifolia wetland ecosystem, soil was the main storage compartment and current hinge of sulfur in which 98.4% sulfur was accumulated, while only 1.6% sulfur was accumulated in the plant compartment. In the plant subsystem, roots and litters were the main storage compartment of sulfur and they remained 83.5% of the total plant sulfur. The calculations of sulfur turnover through the compartments of the typical meadow C. angustifolia wetland ecosystem demonstrated that the above-ground component took up 0.99 gS/m2 from the root, of which 0.16 gS/m2 was translocated to the roots and 0.83 gS/m2 to the litter. The roots took in 1.05 gS/m2 from the soil, subsequent translocation back to the soil accounted for 1.31 gS/m2, while there was 1.84 gS/m2 in the litter and the net transfer of sulfur to the soil was more than 0.44 gS/(m2·a). The emission of H2S from the typical meadow C. angustifolia wetland ecosystem to the atmosphere was 1.83 mgS/(m2·a), while carbonyl sulfide (COS) was absorbed by the typical meadow C. angustifolia wetland ecosystem from the atmosphere at the rate of 1.76 mgS/(m2·a). The input of sulfur by the rainfall to the ecosystem was 4.85 mgS/m2 during the growing season. The difference between input and output was 4.78 mgS/m2, which indicated that sulfur was accumulated in the ecosystem and may cause wetland acidify in the future.     

Nitrogen cycling of atmosphere-plant-soft system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain,Northeast China

The nitrogen(N)distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW)and marsh meadow Calamagrostis angustifolia wetland(MMCW)in the Sanjiang plain were studied by a compartment model.The results showed that the N wet deposition amount was 0.757 gN/(m~2.a),and total inorganic N(TIN)was the main body (0.640 gN/(m~2.a)).The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m~2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m~2,respectively.In plant subsystem,the N was mainly stored in root and litter.Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively.The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m~2.a)and the values of aboveground were 11.31 and 6.08 gN/(m~2.a),the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m~2.a),the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m~2.a),the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m~2.a),the translocation amounts from root to soil were 14.90 and 13.17 gN/(m~2.a),and the soil(0-15 cm)N net mineralization amounts were 1.94 and 0.55 gN/(m~2.a), respectively.The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N,and the status might induce the degradation of C.angustifolia wetland.     

垦殖方式对小叶章湿地表土团聚体有机碳分布的影响

研究了2种垦殖方式对三江平原小叶章湿地表土团聚体及其有机碳分布的影响.结果表明,垦殖后,粒径>0.25mm的大团聚体呈降低趋势,大豆田中0.053~0.25mm微团聚体增加;水稻田中主要增加的是1mm及0.053~0.25mm团聚体有机碳含量降幅均呈现大豆田大于水稻田,水稻田>大豆田,小叶章湿地>大豆田>水稻田.水稻田比大豆田土壤有机碳储量稍高,但其微团聚体有机碳储量及其占土壤有机碳储量的比例低于大豆田,开垦为大豆田比开垦为水稻田有利于土壤有机碳长期存留.     

Nitrogen cycling of atmosphere-plant-soil system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China

The nitrogen (N) distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland (TMCW) and marsh meadow Calamagrostis angustifolia wetland (MMCW) in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/(m2·a), and total inorganic N (TIN) was the main body (0.640 gN/(m2·a)). The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/(m2·a) and the values of aboveground were 11.31 and 6.08 gN/(m2·a), the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/(m2·a), the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/(m2·a), the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/(m2·a), the translocation amounts from root to soil were 14.90 and 13.17 gN/(m2·a), and the soil (0-15cm) N net mineralization amounts were 1.94 and 0.55 gN/(m2·a), respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.     

三江平原沼泽湿地底栖无脊椎动物群落特征

为探明现阶段三江平原沼泽湿地底栖无脊椎动物群落结构及物种多样性,于2017年春、夏、秋3个季节对6个样点开展了调查.共记录3门41科72种,以水生昆虫和腹足纲为主.平均密度为（139.68±29.13）ind./m²,季节上,底栖无脊椎动物密度表现为秋季>春季>夏季.三江平原沼泽湿地主要优势种具有一定的季节性变化,其中,西伯利亚盘螺Valvata sibirica为3个季节共有优势种.指示物种分析表明：春季指示种为Potamonectes sp.,夏季指示种为Lethocerus sp.、Gyraulus centrifugus、Erpobdellidae sp.;秋季指示种为Sgementina nitida.整体上,春季Shannon-Wiener多样性指数（H'）、均匀度指数（J）、Margalef丰富度指数（d_M）均比夏、秋季高.单因素方差分析表明,Shannon-Wiener多样性指数（F=1.480,p=0.259）、Margalef丰富度指数（F=0.056,p=0.946）、Pielou均匀性指数（F=2.038,p=0.165）均不存在季节性差异.     

三江平原挠力河流域湿地生态特征变化研究

经过近半个世纪的垦荒,挠力河流域湿地生态特征发生了明显的改变,大量湿地被垦殖,湿地面积逐年减少;湿地资源的破坏,造成环境污染严重,土壤有机质含量大大降低;土地沙化、盐碱化面积不断扩大;灾害性气候发生频率增加;动植物等多样性资源急剧减少。挠力河流域作为“北大荒”的重要组成部分,生态环境的剧烈变化也就很具有代表性了。伴随着新千年“北大荒”停止一切垦殖湿地、草地和林地的措施出台,挠力河流域也迎来了退耕还林、还牧、还湿的调整时期。     

三江平原湿地生态环境状况研究

采用微观监测和宏观监测相结合的方式,对三江平原湿地类型与面积、湿地水质、生物多样性进行了研究,并分析近5年内湿地景观的变化情况。结果显示:三江平原湿地以沼泽湿地为主,部分地区湿地水质受到污染,主要污染物为高锰酸盐指数、生化需氧量、氨氮和石油类;湿地生物多样性丰富;2004～2009年,三江平原各类湿地面积变化很小。     

三江平原生态环境状况研究

以三江平原各县（市）为研究基本单元,运用生态综合指数法对其生态环境状况进行评价,分析各县（市）生态环境状况。结果表明：三江平原各县（市）生态环境状况分为＂优＂、＂良＂和＂一般＂三个级别。＂优＂类的县（市）共3个,占全区面积的15.96%;＂良＂类的县（市）共19个,占全区面积的82.36%;＂一般＂类的县（市）1个,占全区面积的1.68%。