黑龙江省东部山地白桦人工林对水质的影响

对黑龙江省东部山地白桦人工林生态系统的大气降水、穿透水、树干茎流和地表径流中的pH值、溶解氧、浊度、总溶解固体、电导率、氧化还原电位、K、Na、Ca、Mg、Cu、Zn、Mn和Fe等水质指标进行了测定.结果表明:大气降水经过白桦人工林生态系统后,浊度和总溶解固体值逐渐升高.穿透水除Ca元素外,其他化学元素含量均有不同程度的增加,化学元素含量排序为:K＞ Ca＞ Na＞ Mg＞ Mn＞ Fe ＞Zn＞ Cu.树干茎流中各化学元素含量排序为:K＞Ca＞Mg ＞Na＞Fe ＞Mn ＞Zn ＞Cu.地表径流中各化学元素含量为:K＞ Ca＞ Na＞ Mg＞ Fe＞ Mn＞ Zn＞ Cu.除Na、Ca元素外,大气降水中其他元素的变异系数均较大.穿透水和树干茎流中Cu元素的变异系数大于其他元素,地表径流中Zn元素的变异系数最大.根据淋溶系数的大小排列,穿透水中各化学元素的淋溶序列是:Mn＞K＞Mg＞Fe＞Cu ＞Zn＞ Na＞ Ca.树干茎流中各化学元素的淋溶序列是:K ＞Mn＞ Mg＞ Fe ＞Cu ＞Zn＞ Ca＞ Na.经过淋洗后,穿透水和树干茎流中K和Mg元素增加较多,Ca元素出现负淋溶.     

金属离子对4PCA饲料复合酶中蛋白酶活性的影响

文章研究了8种常见金属离子K+、Na+、Mg2+、Mn2+、Ca2+、Zn2+、Cu2+、Fe2+对4PCA饲料复合酶中蛋白酶活性的影响,离子浓度设定为1×10-4mol·L-1、1×10-3mol·L-1以及1×10-2mol·L-1三个浓度梯度。结果表明:在实验特定金属离子浓度范围下,K+、Na+对酶活无特别影响,Mg2+有一定的激活作用,Mn2+的激活作用最大,Ca2+、Zn2+、Cu2+、Fe2+对酶活有不同程度的抑制作用,其大小顺序依次为Cu2+>Fe2+>Zn2+>Ca2+。     

中亚热带地区几个树种树干茎流的养分特征研究

对湖南株洲22～25年生的樟树、火炬松、槲栎、醉香含笑4个树种树干茎流及林外大气降水中N、P、SiO2、K、Ca、Mg、Cu、Zn、和Mn 9种养分元素含量进行了为期一年的测定.结果表明:不同月份大气降水养分元素含量不同,各元素各月平均含量按大小排序为Ca＞NH4-N＞SiO2＞Zn＞K＞NO3-N＞Mg＞Fe＞Mn＞P＞Cu;大气降水经过林冠层后,树干茎流中各养分元素含量变化基本一致,均表现季节动态变化,相对于大气降水,大多数元素含量增加;不同树种间树干茎流养分特征表现不同,按总含量值排序依次为火炬松、槲栎、樟树、醉香含笑;不同养分元素之间的相对含量也表现出较大的差别,NH4-N、Ca、K、SiO2含量最高,Mg、NO3-N、Zn、Mn含量居中,P、Fe、Cu含量最低.与大气降水相比,4个树种茎流共同表现为,Cu的含量变化较小,其它元素含量均有较大的变化,其中樟树茎流中Zn,SiO2,Fe,Cu;火炬松、槲栎茎流中Zn,Fe;醉香含笑茎流中Zn为负淋洗,4个树种对Zn的负淋洗表现的尤为显著.     

金属离子对4PCA饲料酶中纤维素酶活性的影响

我们研究了8种常见金属离子对4PCA饲料复合酶中纤维素酶活性的影响,离子浓度设定为1×10-4mol·L-1、1×10-3mol·L-1以及1×10-2mol·L-1三个浓度梯度。结果表明:K+、Na+、Ca2+、Mg2+对酶活无特别影响,Cu2+的激活作用最大,Mn2+的抑制作用最大,Zn2+、Fe2+在高离子浓度下对酶活有一定的抑制作用,且Zn2+>Fe2+。     

杉木枯落物燃烧释放污染物特征及PM2.5成分分析

【目的】探究杉木人工林枯落物在不同燃烧状态时的气态及颗粒态污染物排放特征,并提取、测定细颗粒物(PM 2.5 )污染物的化学成分,揭示林火及林地清理等对杉木枯落物分解、养分循环和大气环境的影响。【方法】分别以杉木人工林枯落物中的叶、枝、皮、干4种主要组分为研究对象,运用自主设计的生物质模拟燃烧系统,采用室内模拟燃烧试验,分析阴燃和明燃2种不同燃烧状态不同枯落物组分释放的气态污染物和PM 2.5 特征及差异。采用德国Elementar元素分析仪,测定PM 2.5 中的碳质成分;采用超声提取-离子色谱和ICP/MS技术,测定PM 2.5 中的水溶性离子和水溶性无机元素。【结果】基于杉木枯落物燃烧时的实时测定,CO 2、CO、NO x 、C x H y 、PM 2.5 的排放因子(EF,单位质量燃料在燃烧后产生的污染物质量)变化范围在阴燃条件下分别是1 001.4~1 364.5、202.3~358.8、0.53~3.09、23.17~53.07、5.11~38.37 g ·kg -1 ,而明燃时分别为1 092.4~1 520.7、115.1~242.6、0.16~1.96、1.21~41.50、2.58~21.07 g ·kg -1 。此外,提取测定PM 2.5 成分的结果表明,颗粒物主要由碳质组分、水溶性离子及少量水溶性无机元素等组成。其中碳质组分含量最大,占50%以上,有机碳(OC)和元素碳(EC)平均质量分数分别为43.29%和12.91%;PM 2.5 中测定出6种阳离子(Li +、Na +、NH + 4、K +、Mg 2+、Ca 2+)和5种阴离子(F -、Cl -、NO 2 -、SO 4 2-、NO - 3),总水溶性离子占10%~33%,阴燃以Cl -、K +、Ca 2+、SO 4 2-为主要组分,明燃以K +、Cl -、SO 4 2-、Na +为主;PM 2.5 中提取测定出16种无机元素,分别为K、Ca、Na、Mg、P、Zn、Al、Cu、As、Ba、Cr、Fe、Mn、Cd、Li、Pb,含量极少,仅占PM 2.5 的0.04%~0.58%,其中K、Ca、Na、Mg、P、Zn为主要元素成分,占总无机元素的96.8%~98.8%。【结论】在不同燃烧状态下,杉木枯落物释放各污染物的排放因子存在显著差异,除CO 2外的其他污染物排放因子在阴燃时显著高于明燃;在同一燃烧状态时,杉木枯落物不同组分的CO、CO 2、NO x 、C x H y 和PM 2.5 等污染物的排放因子也存在显著差异。杉木枯落物燃烧排放的PM 2.5 主要由碳质组分、水溶性离子及少量无机元素等成分组成,阴燃时的各成分排放因子整体表现为高于明燃时。     

贵州都匀马尾松种子园针叶DRIS营养诊断分析

通过对都匀1．5代无性系种子园20年生马尾松针叶中N、P、K、Ca、Mg、Cu、Zn、Fe、Mn、B等营养元素含量变化的测定和分析,初步筛选出N／P、K／N、Ca／N、Mg／N、N／Cu、zn／N、N／Fe、K／P、Ca／P、P／Mg、P／Cu、P／Zn、Fe／P、K／Ca、K／Mg、K／Cu、K／Zn、Fe／K、Ca／Mg、Ca／Cu、Ca／Zn、Fe／Ca、MgJCu、Zn／Mg、Fe／Mg、Zn／Cu、Fe／Cu、Fe／Zn共28对元素比值为重要参数,对贵州都匀马尾松种子园针叶作DRIS营养诊断分析。结果表明,该地区马尾松针叶内Mn含量过高,平均值为767．01mg／kg,而B含量较低,仅为12．95mg／kg,马尾松的需肥顺序为Cu〉P〉Zn〉Mg〉Ca〉N〉K〉Fe。     

百山祖冷杉枝叶主要营养元素特征分析

应用原子吸收光谱法测定了百山祖冷杉枝和针叶中K、Na、Cu、Ca、Zn、Fe、Mg、Mn 8种营养元素的含量,结果表明,百山祖冷杉枝和针叶中均含有所测的K、Cu、Ca、Zn、Fe、Mg、Mn等元素,但未检出Na元素;其含量为CaKMgZnFeMnCuNa。与大多数植物体正常生长发育的元素含量范围值相比较,百山祖冷杉枝和针叶中K含量分别为2 967.68~5 585.95、4 036.13~5 194.30 mg/kg,均低于临界值,针叶中Cu含量2.58~4.70 mg/kg,略低于一般植物水平,枝部Zn、Mn含量及针叶Mn含量则均处于较高水平。     

枫香人工林林冠截留降水分配及养分特征

采用定位研究方法,根据2007年5月到2008年3月的观测数据,对长沙市天际岭林场枫香人工林生态系统的降水再分配中养分输入进行了研究。结果表明:林外降水、穿透水中以Ca含量最高;树干茎流中NH4+-N的含量最高;NH4+-N、NO3--N、P、Ca、K、Mg、Cu、Mn含量在穿透水和树干茎流中呈上升趋势,其中Mn含量增加幅度最大;Fe、Zn、Cd元素含量在穿透水和树干茎流中呈下降趋势;降水再分配过程中各元素含量随着降水量的增加而降低。     

4个树种茎流养分特征研究

对湖南株洲22~25年生的樟树、枫香、杜仲、桂花4个树种树干茎流及林外大气降水中N、P、SiO2、K、Ca、Mg、Cu、Zn和Mn9种养分元素含量进行为期1年测定。结果表明:不同月份大气降水养分元素含量不同,各元素各月平均含量按大小排序为Ca>SiO2>Zn>NH4 -N>K>NO3--N>Fe>Mg>Mn>P>Cu;大气降水经过林冠层后,树干茎流中各养分元素含量变化基本一致,均表现季节动态变化,相对于大气降水,大多数元素含量增加;树种之间的茎流养分特征表现不同,按总含量值排序依次为枫香、杜仲、樟树、桂花;不同养分元素之间的相对含量也表现出较大的差别,养分含量中K、Ca、NH4 -N、SiO2含量最高,NO3--N、Mg、Mn、Zn居中,Fe、P、Cu最低;4个树种共同表现出对Fe、Zn的负淋溶,尤以Zn最显著。     

不同年龄秦岭细鳞鲑肌肉中矿质元素含量特征

采集太白山南坡红水河野生细鳞鲑肌肉样品,采用原子吸收光谱法测定K、Na、Ca、Mg、P、Cu、Fe、Mn、Zn元素含量。结果表明:细鳞鲑肌肉中常量元素K平均含量很高,而Na含量相对较低;微量元素Zn和Fe含量较丰富,同时,1龄鱼肌肉中Ca及Cu、Mn和Zn含量最高。随年龄增长,细鳞鲑肌肉中矿质元素含量也发生了改变。     

Deposition pattern of precipitation and throughfall in a subtropical evergreen forest in south-central China

The effects of dry deposition, canopy leaching, precipitation ion concentration, and precipitation H⁺ concentration on net throughfall flux (NTF, throughfall minus bulk precipitation) were evaluated on a seasonal basis by using a multiple regression analysis approach based on an observation period of 4 years in Shaoshan subtropical mixed evergreen forest, south-central China. Regression analysis results indicated that the estimated canopy exchange flux was the dominant factor regulating the NTF and the calculated dry deposition was a minor term. The seasonal dry deposition of base cations accounted for 15%–43% of the NTF. The NTF analysis showed that K⁺, Ca²⁺, Mg²⁺, Na⁺, and weak acids in throughfall were derived from foliar leaching and the canopy uptakes of H⁺, NH₄ ⁺, and NO₃ ⁻ were from precipitation. The retention rate of proton (H⁺ and NH₄ ⁺) in the canopy was close to the canopy leaching rate of base cations when corrected for weak acids because weak acid-induced canopy leaching did not exchange with protons, which suggested that the canopy leaching processes neutralized acid precipitation in Shaoshan forest.     

Multiple modelling of water chemistry flows assessed in a mountain spruce catchment

The study was carried out over a period of 1999–2003 in the Dupniański Stream catchment located in Silesian Beskid Mts. Region (Southern Poland). Analysis of the chemical composition of bulk precipitation, throughfall, stemflow, surface flow, soil water (horizontal + vertical and vertical penetration) and outflow water samples was performed. The complex data matrix with more than 3,000 observations of water reaction, major anions (F⁻, Cl⁻, NO₃ ⁻, SO₄ ²⁻) and cations (NH₄ ⁺, Na⁺, K⁺, Ca²⁺, Mg²⁺, Fe²⁺, Mn²⁺ and Zn²⁺) were treated by regression modelling. The modelling approach took into account seasonal variability according to winter and growing season, as well as chronosequence of spruce stands. The retention of considerable levels of contaminants by the canopy, and their removal or washout from needles by rainfall caused changes in the concentration of anions and cations reaching the soil surface compared to the concentrations in bulk precipitation. In the youngest stand, most elements except NH₄ ⁺, SO₄ ²⁻ and K⁺ were retained in the canopy, and even H⁺ ions were neutralized. In the older stands, most elements increased in net throughfall fluxes, and the acidity increased strongly. Soil water was slightly correlated with throughfall, while outflow water showed no correlations with the above ground water flows, and seemed to depend mostly of the bedrock.     

理化因素对桑果色素性质的影响

桑树(Morus abla L.)为桑科(Moraceae)桑属(Morus L.)植物,我国栽培历史悠久,分布广泛[1]。桑果(Mulberry)为桑树的果实,含花色苷类化合物,同时含有维生素、糖、氨基酸、矿物质等营养成分,是开发天然色素的良好材料[2-3]。天然色素使用安全,色泽自然,多具有一定的营养和保健作用,对保护人们健康和促进食品工业发展具有重要意义[1]。但天然色素     

Effect of clear-felling and slash removal on the acidity of Northern coniferous soils

Measurements of pH were carried out at two experimental sites in Sweden before and after clear-felling. At eleven sites, pH, cation-exchange capacity, base saturation and exchangeable hydrogen ions were compared in clear-felled areas where slash was left and removed, respectively. It is shown that pH increases significantly after clear-felling. The increase is larger than can be explained by the release of basic cations in connection with decomposition of slash and humus. The increase in pH is less in a clear-felled area when the slash is removed than when it is left. There is a decrease in exchangeable Ca²⁺, Mg²⁺ and Mn²⁺ and an increase in H⁺ and Al³⁺. There is a decrease in base saturation of about 80%.     

重庆酸雨区缙云山典型林分冠层酸雨淋洗特征

选取重庆缙云山的针阔混交林、常绿阔叶林、毛竹林、灌木林4种典型林分,观测酸性降水过程中林外雨、穿透雨及干流等林内水分转换分量中的主要离子含量变化,分析林分冠层对雨水化学组成的影响,结果表明:(1)降雨中的离子当量浓度大小依次是SO42-＞Ca2+＞ NH4+＞Mg2+＞K+＞Na+＞NO3-;(2)降雨经过林冠层后pH值降低,干流的酸化程度增加最大;(3)降雨经林冠层后离子浓度明显增加(除灌木林),穿透雨中通量增加最大的阴离子和阳离子分别为SO42-(2.19×103～6.47×103 eq·hm-2)和Ca2+(1.41×103～3.39×103 eq-hm-2),离子来源主要为大气沉降和植物分泌物或淋出;(4)同一离子在不同林分的干流和穿透雨中的通量变化不同,反映出不同林分冠层的离子交换性差异.在针阔混交林中,林下降雨净淋溶量大小顺序为SO42-＞Ca2+＞ NO3-＞K+＞NH4+＞Mg2+＞ Na+;常绿阔叶林为SO42-＞ Ca2+＞ K+＞NO3-＞ NH4+＞ Mg2+ ＞Na+;毛竹林为Ca2+＞ SO42-＞ K+＞NO3-＞ NH4+＞Na+＞Mg2+;灌木林为Ca2+＞ NO3-＞ K+＞ Na+＞Mg2+＞ NH4+＞ SO42-.     

Deposition patterns in bulk precipitation and throughfall in a subtropical mixed forest in central-south China

The chemistry and deposition pattern in bulk precipitation andthroughfall (TF) were examined and evaluated based on the 3-yearobservations in Shaoshan subtropical deciduous-conifer mixedforest in central-south China. The TF chemistry was notablychanged when passing through canopies, which probably was attributedto the dry deposition (DD) on leaf surface and the canopy exchanges.Base cations' (Ca²⁺, Mg²⁺ and K⁺) fluxes were significantlyenriched in TF, in particular for K⁺. The annual K⁺ canopy exchangewas 12 times larger than DD, and canopy exchange of Ca²⁺, Mg²⁺and K⁺ was four times as high as the DD. The canopy exchangeof base cations in association with weak acid accounted for28.4 per cent of total leached base cations, which was one ofthe important factors to modify the TF chemistry.     

An assessment of rainfall modification in mountainous ecosystems dominated by Fagus sylvatica L. and Picea abies (L.) Karst. (Western Balkans,Bulgaria) by multivariate analyses

Bulk precipitation, throughfall, and stemflow samples were collected in Petrohan site (Western Balkan, Bulgaria), operating in the framework of the Long-Term Ecological Research network, during a 6-year period (1995–2000). This mountain area is characterized by the presence of beech and spruce forests (Fagus sylvatica L. and Picea abies (L.) Karst.) and is utilized for drinking water supply. All samples were analyzed for pH and major inorganic anions (Cl^?, NO₃ ^?, and SO₄ ^2?) and cations (Ca²⁺, K⁺, Mg²⁺, Na⁺, and NH₄ ⁺). Results show that bulk precipitation in this region is mainly acidic (pH = 5.1), and the dominant neutralization components in the rainwater are Ca²⁺ and NH₄ ⁺. As for Ca²⁺, K⁺, Mg²⁺, Cl^?, and SO₄ ^2?, they are not originated by marine source. Cluster analysis and principal component analysis were used for investigating the possible sources contributing to the chemical composition of the bulk precipitation and its possible modifications during the passing through beech and spruce stands. Results highlight that local and long-range transport-related anthropogenic sources and natural sources contribute to the anion and cation content of the bulk precipitation. The enrichment of the solution through the foliage made up of dry depositions is significant in both stands, but canopy leaching processes are much greater in the spruce forest, especially for Ca²⁺. As for the stemflow, it follows the same pattern as the throughfall, but N uptake and a strong K⁺ and Mg²⁺ leaching are observed mainly in the spruce stand.     

Canopy leaching of subtropical mixed forests under acid rain

Leaching of major ions from acid precipitation in a subtropical forest was examined based on an experiment in four sample sites in Shaoshan City, Hunan Province, China, from January 2001 to June 2002. Results clearly show that when rain passed through the canopy, pH increased and the evidence of ion uptake was presented for SO₄ ²⁻, NO₃ ⁻, Mg²⁺ and NH₄ ⁺ ions, especially of NH₄ ⁺ and NO₃ ⁻. The percentages of dissolved SO₄ ²⁻, Ca²⁺ and Mg²⁺ show a decreasing trend with increasing rainfall. Percentages of leaching Ca²⁺, K⁺ and Cl⁻ ions show an increasing trend as a function of increased pH values. The forest canopy in Shaoshan City has a strong effect on the uptake of SO₄ ²⁻ and NO₃ ⁻ ions under acid rain conditions. The decreasing order of ions leaching in the forest canopy is as follows: K⁺ > Ca²⁺ > Cl⁻ > Mg²⁺ > SO₄ ²⁻ > NO₃ ⁻ > NH₄ ⁺ > Na⁺. __________ Translated from Scientia Silvae Sinicae, 2007, 43(7): 1–4 [译自: 林业科学]     

Determination of cations and anions in the ashes of some medicinally used tropical woods

Summary The ashes of some medicinally used tropical woods were characterised. These were Afzelia africana, Alstonia congensis, Antiaris africana, Terminalia ivorensis, Azadirachta indica, Ricinodendron heudelotti, Chlorophora excelsa and Daniellia ogea. The ashes were obtained by treating wood in a muffle furnace, after which the ashes dissolved in distilled water. The very alkaline solutions obtained were analysed for Na⁺, K⁺, Ca²⁺, Mg²⁺, Mn²⁺, Fe²⁺, Cu²⁺, Cl^-, SO ₄ ^2- and PO ₄ ^3- . Due to wide medicinal application of these wood species experiments were made to determine the cations and anions which may be active ingredients in the compounds (drugs) used in the treatment of differet ailments.The authors are thankful to A. Amusan of Soil Science Department, Obafemi Awolowo University, Ile-lfe for technical assistance