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.     

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.     

气候变化情景下湿地净初级生产力风险评价

采用BIOME-BGC模型,模拟了气候变化情景下(A1B, A2, B2)三江平原富锦地区小叶章(Calamagrostis angustifolia)湿地的净初级生产力(NPP)变化,并通过NPP变化情况评价小叶章湿地风险等级.结果表明:未来30年(2013~2042年)各气候情景下富锦小叶章湿地NPP均值均高于基准期均值(1961~1990), A1B和B2情景下未来30年间NPP波动范围变大,A2情景下NPP有降低趋势.风险评价结果表明,气候变化情景下小叶章湿地存在一定风险,尤其是在A1B情景下,未来30年中可能有6年以上的年份存在高风险,A2情景下湿地风险最低.湿地NPP变化与降水量呈显著正相关(R2=0.58,P<0.05),说明降水量是影响区域湿地的重要因素.尽管气候变化情景下假设了存在升温?CO2浓度升高等有利于植物生长的因素,但降水量的的剧烈变化以及极端气候事件的增加,可能会导致湿地在未来气候变化情景下面临较高风险,未来湿地保护与管理过程中应重点关注水的补给和调配.     

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.     

三江平原小叶章湿地土壤微生物活性特征研究

选取三江平原河滨湿地、沼泽湿地和草甸化湿地3种类型小叶章湿地0~20cm土壤,研究了不同类型湿地土壤总有机碳(TOC)、微生物生物量碳(MBC)、微生物生物量氮(MBN)、基础呼吸(BR)、呼吸势(PR)、微生物熵(Cmic/Corg)和代谢熵(qCO2)变化规律.结果表明,不同类型小叶章湿地土壤总有机碳、微生物生物量碳和基础呼吸分别为46.60~75.44g.kg-1、1106.86~2319.42mg.kg-1和5.72~10.10mg.kg-.1h-1.河滨湿地和沼泽湿地土壤总有机碳、微生物生物量碳、微生物生物量氮、基础呼吸、呼吸势和微生物熵均显著高于草甸化湿地(p0.01),而河滨湿地和沼泽湿地代谢熵明显低于草甸化湿地(p0.05).各土壤微生物活性指标在河滨湿地和沼泽湿地间均无明显差异.因而,相对于河滨湿地和沼泽湿地,草甸化湿地土壤微生物活性处于较低水平,土壤总有机碳和水分含量低是限制草甸化湿地土壤微生物活性的重要因素.     

Influence of environment and substrate quality on the decomposition of wetland plant root in the Sanjiang Plain, Northeast China

The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast China.These wetlands are Calamagrostis angustifolia(C.aa),Carex meyeriana(C.ma)and Carex lasiocarpa (C.la).The objective of our study is to evaluate the influence of environment and substrate quality on decomposition rates in the three wetlands.Calico material was used as a standard substrate to evaluate environmental influences.Roots native to each we...     

土地利用变化对三江平原生态系统服务价值的影响

近年来三江平原土地利用的变化很大,研究其生系统服务价值的变化情况,可以为区域生态环境的保护和恢复提供科学依据.参照中国陆地生态系统单位面积服务价值表,利用三江平原两期土地利用数据,估算了土地利用变化引起的生态系统服务价值的变化.结果表明,1980～2000年三江平原耕地、城镇用地和水域面积有所增加,其余类型面积减少.其中耕地面积增加了30.70%;湿地面积减少了53.37%,该区域人文景观的影响已超过了自然景观.1980～2000年三江平原生态系统服务价值损失了538.8710⁸元,损失幅度为28.62%.大面积湿地转化为农田是生态系统服务价值大幅度下降的主要原因.     

开垦利用对三江平原湿地土壤硫含量的影响

以三江平原典型类型湿地及不同开垦年限的耕地 (旱田 )为研究对象 ,对其土壤中总硫及各形态硫的含量变化进行分析 ,结果如下 :总硫、水溶性硫、吸附性硫、盐酸可溶性硫、盐酸挥发性硫及有机硫含量排序均为小叶章 (Calamagrostisangusti folia)草甸 <乌拉苔草 (Carexmeyeriana)沼泽 <毛果苔草 (Carexlasiocarpa)沼泽 ;湿地开垦为耕地后 ,除盐酸可溶性硫含量增加以外 ,其余硫组分的含量均有不同程度的降低 ;耕地土壤中总硫及有机硫含量随开垦年限的增加而下降 ,而无机硫各组分随开垦年限的增加变化量不大 .湿地开垦前土壤总硫量为 6 2 2 4mg kg ,湿地开垦 2 0年后 ,土壤总硫量降低为 16 8mg kg ,因此在人类活动的干预下湿地开垦后表现出由汇转化为源 ,由累积转化为分散的特征     

Dynamics of dissolved organic carbon in the mires in the Sanjiang Plain, Northeast China

Mires in boreal area had proved to be an important dissolved organic carbon (DOC) reserve for the sensitivity to climate change and human interfering. The study was focused on the temporal and spatial dynamics and controlling factors of DOC in a seasonallywaterlogged mire (SLM) and perennially-waterlogged mire (PLM) in the Sanjiang Plain, Northest China. In the two mires, DOC concentrations in both surface water and upper soil strata experienced pronounced seasonal variation. DOC concentrations in the surface waters were the greatest and averagely was 47.82 in SLM and 34.84 mg/L and PLM, whereas that in soil water at 0.3-m depth had little di erence (20.25 mg/L in SLM and 26.51 mg/L in PLM). Results revealed that DOC concentrations declined 5–8 times vertically from the surface down to groundwater. DOC in the groundwater only was in a very small part with the average concentration of 5.18 mg/L. In relation to the surface water, DOC concentrations varied positively with temperature just before 8 August, and only in early spring and later autumn DOC concentrations exhibited identifiable spatial trends along with standing water depths in PLM. It was supposed that the influences from standing water depth took e ect only in conditions of low temperature, and temperature should be the most powerful factor controlling DOC dynamics in the mires. Redox potential (Red) showed negative relationship with DOC values while total nitrogen (TN) and the majority of free ions in the soil solution exhibited no relationship. High soil TOC/TN ratio and low redox potentials also led to DOC accumulation in the mires in the Sanjiang Plain.     

三江平原多级沟渠系统沉积物中铁的分布特征

以三江平原典型多级沟渠系统(毛渠-农渠-斗渠-支渠-干渠)为对象,研究了其0～60 cm沉积物全铁含量的空间分布特征.结果表明,多级沟渠系统中沉积物的平均铁含量为(3.02±0.10)×104 mg·kg-1,各类型、各等级的沉积物铁含量具有极显著差异(F=6.261,p<0.001),最高值出现在农田斗渠(3.71×104 mg·kg-1)中,而最低值出现在湿地斗渠(2.43×104 mg·kg-1)中.整个多级沟渠系统沉积物各层的铁含量没有显著性差异(F=0.093,p=0.693),但与沟渠相邻湿地同深度土层的铁含量相比,沟渠沉积物0～10 cm层、10～20 cm层分别增加了51.96%、62.22%.铁虽然具有一定的可迁移性,其最大累积处仅能延伸到第三等级的斗渠中,而非逐级递增.由于湿地保护和气候干热化,现阶段本区含铁径流量有逐渐减少的趋势.沉积物各层铁含量沿沟渠类型和等级的递变揭示了铁输移的历史变迁.     

Distribution characteristics of dissolved organic carbon in annular wetland soil-water solutions through soil profiles in the Sanjiang Plain, Northeast China

Overwhelming evidence reveals that concentrations of dissolved organic carbon （DOC） have increased in streams which brings negative environmental impacts. DOC in stream flow is mainly originated from soil-water solutions of watershed. Wetlands prove to be the most sensitive areas as an important DOC reserve between terrestrial and fluvial biogeosystems. This reported study was focused on the distribution characteristics and the controlling factors of DOC in soil-water solutions of annular wetland, i.e., a dishing wetland and a forest wetland together, in the Sanjiang Plain, Northeast China. The results indicate that DOC concentrations in soilwater solutions decreased and then increased with increasing soil depth in the annular wetland. In the upper soil layers of 0-10 cm and 10-20 cm, DOC concentrations in soil-water solutions linearly increased from edge to center of the annular wetland （R^2 = 0.3122 and R^2 = 0.443）. The distribution variations were intimately linked to DOC production and utilization and DOC transport processes in annular wetland soil-water solutions. The concentrations of total organic carbon （TOC）, total carbon （TC） and Fe（II）, DOC mobility and continuous vertical and lateral flow affectext the distribution variations of DOC in soil-water solutions. The correlation coefficients between DOC concentrations and TOC, TC and Fe（II） were 0.974, 0.813 and 0.753 respectively. These distribution characteristics suggested a systematic response of the distribution variations of DOC in annular wetland soil-water solutions to the geometry of closed depressions on a scale of small catchments. However, the DOC in soil pore water of the annular wetland may be the potential source of DOC to stream flow on watershed scale. These observations also implied the fragmentation of wetland landscape could bring the spatial-temporal variations of DOC distribution and exports, which would bring negative environmental impacts in watersheds of the Sanjiang Plain.     

东北三江平原土壤氧化CH4研究

三江平原土壤不同深度氧化大气浓度CH4和高浓度CH4的速率具有明显的垂直差异 .2个非淹水土壤整个剖面都具有氧化大气浓度CH4的潜力 ,以表层土的速率为最大 .非淹水的耕作土壤残留的有机质层仍保留了较强的氧化大气浓度CH4潜力 ,氧化CH4速率是耕作层的 2 0倍 .淹水土壤的大部分层次不具有氧化大气浓度CH4的潜力 .所有供试土壤均能消耗高浓度CH4,泥炭含量较高的土壤层次比矿质层氧化高浓度CH4的速率高     

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%。     

三江平原作物收获期大气颗粒物浓度特征

通过对2013年10月东北三江平原农作物收获期大气颗粒物的在线监测,结合卫星火点数据与后向轨迹模拟,分析了秸秆燃烧和作物收割等农业活动对大气颗粒物质量浓度及粒径分布的影响.结果表明:作物收获前期?中期和后期大气PM2.5的平均质量浓度分别为36.0,158.3,33.8μg/m3;现场观测表明,水稻收割(321.1μg/m3)和秸秆燃烧(2777.1μg/m3)时监测田块内PM2.5的平均浓度分别是收割前和燃烧前平均浓度的2.5倍和11.5倍;卫星火点及后向轨迹分析发现,观测期间PM2.5与该地区卫星火点数量的变化趋势比较一致,且气团轨迹经过火点较集中区域时测得较高的PM2.5浓度值;对不同粒径(<1μm,1~2.5μm,2.5~10μm)大气颗粒物质量浓度的观测表明,收获中期受大面积秸秆燃烧的影响,0~1 μm粒径组分明显增加,而收获后期由于降水过程对0~1μm粒径颗粒物的清除效率较低,故该粒径颗粒物仍维持较高比例.     

Temporal variability of iron concentrations and fractions in wetland waters in Sanjiang Plain, Northeast China

Chemical forms, reactivities and transformation of iron fractions in marshy waters were investigated with cross-flow filtration technique to study the iron environmental behavior. Iron fractions were divided into four parts: acid-labile iron (pre-acidification of unfiltered marshy water samples, 0.7 μm), high-molecular-weight iron (0.7-0.05 μm), medium-molecular-weight iron (0.05-0.01 μm), and low-molecular-weight iron ( 0.01 μm). The cross-flow filtration suggested that iron primarily exist in both the 0.7 μm and 0.01 μm size fractions in marshy waters. Rainfall is the key for rain-fed wetland to determine fate of iron by changing the aquatic biochemical conditions. By monitoring the variation of iron concentrations and fractions over three years, it was found that dissolved iron and acid-labile iron concentrations exhibit a large variation extent under different annual rainfalls from 2006 to 2008. The seasonal variation for iron species proved that the surface temperature could control some conversion reactions of iron in marshy waters. Low- molecular-weight iron would convert to acid-labile iron gradually with temperature decreasing. The photochemical reactions of iron fractions, especially low-molecular-weight iron had occurred under solar irradiation. The relative proportion of low-molecular-weight in total dissolved iron ranging from 28.3% to 43.2% were found during the day time, which proved that the observed decreasing concentration of acid lability iron was caused by its degradation to low molecular weight iron.     

三江平原土地利用方式变化对土壤锰形态影响

在充分调查三江平原不同土地利用方式下土壤中锰含量及其形态分布特征的基础上,探讨了环境因子与土壤中不同锰形态的关系,以揭示锰形态变化对土地利用变化改变的响应.湿地土壤中总锰(Mntot)含量处于较低水平.不同土地利用方式下,林地土壤中Mntot要高于湿地和农田.湿地垦殖为旱田,土壤Mntot有增加趋势;湿地垦殖为水田,土壤Mntot有减少趋势.三江平原土壤中锰主要以残渣态(Mnres)和可还原态(Mnred)为主,可交换态(Mnext)与可氧化态锰(Mnoxi)含量次之.湿地、旱田及水稻田这3种土地利用方式下,土壤中可氧化态锰含量占总锰比例差异显著.湿地垦殖方向不同,对土壤中可氧化态锰影响最大.三江平原土壤中Mntot及不同锰形态含量主要受到土壤中S、pH、DOC这3种环境因子影响.     

黑龙江省粮食生产与三江平原湿地协调发展水平的评价

为寻求黑龙江省农作物播种面积和湿地面积两者间的合理比例,使之既能保证粮食生产,又能维持湿地的必要功能,论文首先用模糊评价方法对历年黑龙江省粮食生产效益和湿地效益分别进行了评价,在此基础上,对反映两方面和谐共存程度的协调发展水平进行了评价。评价结果显示,20世纪70年代末到80年代初这一时期的农业生产和湿地环境是比较协调的。该时期农作物播种面积为870×104hm₂,三江平原湿地面积约为195×104hm₂。此结果可以作为设定三江平原湿地恢复程度的一个参考标准。在该标准下,按高单产水平计算,黑龙江省可提供2930×104t粮食,而三江平原湿地植物和鸟类的种类数约可分别恢复到建国时水平的70%和80%。     

三江平原草甸白浆土P、K养分含量特征及影响因素

在三江平原湿地植物生长季节期内,选择具有代表性的小叶章湿地发育的草甸白浆土为研究对象,逐月分层采集土样,测定其P、K含量.在此基础上借助SPSS软件和灰色关联分析技术,探讨了草甸白浆土中P、K含量的分布特征及相关环境因子对P、K含量动态变化的影响.结果表明:草甸白浆土中P、K含量在剖面垂直方向具有明显的分层现象,P、K分布与土层的相关性均较好,相关系数均在0.94以上.此外,草甸白浆土各土层P、K含量在植物生长季节均呈明显的动态变化,用一元三次非线性回归模型可得到较理想的拟合结果.同一环境因子对草甸白浆土各土层中全P、全K、速效P及速效K的动态分布影响程度不同;不同环境因子对同一土层中P、K的动态分布影响程度更不同.降水量在所有环境因子中影响程度最大,且土壤表层受环境因子的影响较底部土层敏感.     

湿地景观破碎化对东方白鹳栖息地的影响——以三江平原东北部区域为例

以野外栖息地要素调查为基础,通过模型定量化分析,研究了三江平原东北部湿地景观破碎化过程及其对东方白鹳栖息地的影响。结果显示:当景观面积占区域面积超过50%,景观连通度高于50时,景观基质处于低度破碎化状态,景观斑块面积丧失对栖息地影响显著;当景观面积占区域面积小于30%,景观连通度低于30时,景观处于高度破碎化状态,景观空间隔离、斑块形状以及景观结构对栖息地影响更为显著。景观破碎化过程中,沼泽湿地主要在面积丧失方面对东方白鹳觅食地产生影响;而湖泡和岛状林湿地在斑块数量丧失和空间隔离方面对东方白鹳筑巢地和觅食地产生显著影响。