北京地区不同湿地植物对生活污水的净化效果研究

选择北京地区芦苇、东方香蒲、水芹、睡菜和蒿柳5种湿地植物,设计6种不同的植物配置方式,研究不同湿地植物单种及其配置对水中pH值、化学需氧量(COD)、总氮(TN)和总磷(TP)的净化效果。通过连续6个月的动态监测,结果表明:湿地植物对污染物有明显的净化效果,且9月份前随着温度的升高和植物的生长逐步提高,9月份后净化效果上升趋势趋于缓和或下降。单种湿地植物中,东方香蒲对pH值净化效果最好,睡菜对COD净化效果最好,芦苇对TN净化效果最好,蒿柳对TP净化效果最好,东方香蒲、蒿柳对上述污染物的综合净化效果最好;从湿地植物单种和植物配置对污染物的净化效果比较来看,植物配置对pH值、TN的净化效果高于单种,而对COD和TP的净化效果低于单种,芦苇和睡菜适合与其他植物配置使用,而东方香蒲、蒿柳和水芹单种使用对污染物的综合净化效果高于与其他植物配置的效果。     

Different arbuscular mycorrhizae and competition with an exotic grass affect the growth of Podocarpus cunninghamii Colenso cuttings

There is growing interest in the use of arbuscular mycorrhizal fungi (AMF) for ecological restoration. Numerous commercial AMF products are now available and are often used in preference to collecting indigenous AMF in treating restoration plants. Commercial AMF products are typically based on AMF strains exotic to the plant species and locations where they are used. We treated rooted cuttings of an endemic New Zealand tree species (Podocarpus cunninghamii) and an exotic and invasive grass (Agrostis capillaris) with an indigenous, pot-cultured AMF (Acaulospora laevis) and an exotic commercial AMF product (Glomus spp.). P. cunninghamii was grown in monoculture and together with A. capillaris, the latter to simulate field competition that often occurs in restoration plantings. In monoculture, the indigenous AMF resulted in significant increases in P. cunninghamii growth rates and tissue concentrations of both nitrogen and phosphorus. The commercial AMF had either no effect or a negative effect on P. cunninghamii growth and nutrient levels. A. capillaris growth and nutrient status were unaffected by the different AMF treatments. Competition eliminated any AMF benefit for P. cunninghamii. The results show that, for our chosen indigenous woody plant species, the commercially available AMF did not improve its early growth and nutrient acquisition in monoculture while, over the same period, the indigenous AMF induced positive growth and nutrient responses. These results have potential implications for forest restoration, particularly for nursery production of indigenous woody species.     

Effects of discharge level on the load of dissolved and particulate components of stream nitrogen and phosphorus from a small afforested watershed of Japanese cypress (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>)

The behavior of dissolved and particulate components of stream nitrogen (N) and phosphorus (P) were measured for 2 years in a small mountainous watershed covered primarily with a plantation forest of Japanese cypress (Chamaecyparis obtusa). The load of dissolved N and P bore a consistent relationship to discharge while the load of particulate N and P varied by up to two orders of magnitude at a given discharge level. Most N was exported in a dissolved form (DN) while most P was exported in a particulate form (PP), which bears similarity to loads from agricultural watersheds. Owing to the different behaviors of DN and PP, changes in the total nitrogen (TN) load were primarily attributed to variations in discharge unlike changes in the total phosphorus (TP) load. High flow conditions, resulting from heavy rainfall, displayed PP release significantly larger than expected. The TP load in high flow conditions was severely underestimated using a regression equation expressed as a function of discharge, which was based on the weekly sampling data biased toward low flow conditions. In addition, the TN load during peak discharges in heavy rain events was underestimated by the regression equation because of unpredictable increases in the particulate component. Our study shows that the particulate component ratio determines whether discharge can explain changes in load regardless of chemical species. The results suggest that plantation forests in rainy regions can be a diffuse source of particulate nutrients depending on soil surface conditions.     

晋西黄土区不同森林树种及其林地土壤养分含量的变化

[目的]探究晋西黄土区不同树种营养器官(叶、枝、干、根)及其土壤的养分含量变化特征。[方法]通过野外样地调查和取样分析方法,对3种典型森林树种(刺槐、侧柏、辽东栎)不同器官及其林地土壤有机碳、全氮、全磷含量进行了研究,并探讨了不同树种叶片与其土壤C、N、P化学计量的关系。[结果]辽东栎、刺槐和侧柏的叶片有机碳含量分别为468.43、454.96、438.53 g·kg-1,刺槐、辽东栎和侧柏叶片的全氮含量分别为27.52、20.74、12.73 g·kg-1,辽东栎、侧柏和刺槐叶片的全磷含量分别为2.73、2.15、1.35 g·kg-1,叶片C∶N值为侧柏辽东栎刺槐,C∶P、N∶P值分别为刺槐侧柏辽东栎、刺槐辽东栎侧柏;3个树种树枝的有机碳含量均最大,树叶的全氮含量均最大,而树干的全氮含量均最小。侧柏、辽东栎、刺槐树枝的全磷含量分别为3.07、3.07、1.87 g·kg-1,显著比其它器官的大;3种森林土壤的C、N、P含量均随土层的加深而降低,且0 10 cm土层的含量最大,C∶N、C∶P、N∶P值随土层深度的变化不一致;刺槐叶片的有机碳、全磷含量与土壤C∶N值显著或极显著负相关;侧柏叶片的有机碳含量均与土壤C∶N、C∶P、N∶P值极显著负相关,叶片N∶P值与土壤C∶N、C∶P、N∶P值均极显著正相关;辽东栎叶片的有机碳含量、C∶P值与土壤有机碳含量极显著负相关。[结论]辽东栎、刺槐和侧柏的有机碳含量均较高,分别为468.43、454.96、438.53 g·kg-1;辽东栎和刺槐对晋西黄土区干旱环境的防御能力比侧柏强,当地环境较适宜辽东栎的生长发育,而刺槐和侧柏的生长分别受土壤P和N的限制。     

Effects of submergence in water on seed germination and vigor of the Copaifera lucens （Fabaceae） seedlings

We analyzed the tolerance of Copaifera lucens seeds to sub- mersion in water to assess the use of this species for direct seeding in riparian forest restoration programs. Seeds were submerged in water for 2, 4, 8, 16 and 32 days or not submerged （control = 0 days of submer- gence）. For the control and at the end of each period of submersion, germination and seedling vigor tests were carried out. For germination tests, seeds were sown in plastic pots containing sand and kept in labora- tory conditions. The percentage of seed germination, the germination rate and the average germination time were analyzed. For seedlings, total biomass, leaf area, leaf mass per area and leaf area ratio were analyzed. Submersion time drastically affected the dissolved oxygen content and seed germination. Between 4 and 8 days of submersion there was a de- crease from 83.8% to 15.6% in the germination percentage. No seed germination occurred after 16 days of submersion. Although there was a significant decrease in the percentage of seed germination between 4 and 8 days of submersion, seedling vigor was not affected. Seeds of this species were partially tolerant to submersion in water, suggesting that C. lucens is a promising species for direct seeding in riparian forest restora- tion projects.     

Climate,plant organs and species control dissolved nitrogen and phosphorus in fresh litter in a subalpine forest on the eastern Tibetan Plateau

Key message

Fresh litter contains a higher concentration of dissolved phosphorus (DP) than dissolved nitrogen (DN), which implies a more efficient DN transformation or reabsorption in the subalpine forest on the eastern Tibetan Plateau. Both DN and DP concentrations increased with the increase of mean monthly temperature, although the concentrations were also regulated by plant organs and species.

Context

The dissolved nitrogen (DN) and dissolved phosphorus (DP) released from fresh litter are important pathways by which total nitrogen and phosphorus are transferred from the vegetation to soil in forest ecosystems. However, few studies have paid attention to the DN and DP in fresh litter, which affects our understanding of the nitrogen and phosphorus cycles.

Aims

The objectives of this study were to elucidate the dynamic characteristics of the concentrations and storage of DN and DP, and to analyze how DN and DP are affected by different plant species and organs, and climate factors.

Methods

Fresh litter was collected in three plots in a spruce-fir forest and classified by different plant species and organs. Concentration and storage of DN and DP in fresh litter were determined and related to the climatic variables that were monthly recorded.

Results

The concentration of DP was higher than that of DN in fresh litter, and the concentrations of both elements were determined by plant organs and species. Moreover, The DN and DP concentration was positively related to mean monthly temperature, while DN and DP storage was negatively correlated with mean monthly temperature and monthly precipitation. The storage of DN and DP was determined by litter biomass, which the order in litter from different plant organs was leaves>twigs>miscellaneous>flowers and fruits. The storage of DN and DP in leaves showed two peaks in April and October, but that in twigs and the miscellaneous showed only one peak in October.

Conclusion

Our results indicated that dissolved nitrogen (DN) is transferred and reabsorbed more than dissolved phosphorus (DP) before plant leaf senescence and other organs fall. Furthermore, DN and DP were associated with climate, plant organs and species in a subalpine forest on the eastern Tibetan Plateau.

     

长白落叶松容器苗个体营养特征研究

通过对1年生长白落叶松播种容器苗不同生长期内N、P、K浓度进行分析,得到在幼苗生长初期,整株的N、P、K含量均为最低;进入速生期时,植株中全氮、全磷达到最大值,而全钾则在速生后期才达到最大值。长白落叶松植株N、P代谢之间呈显著的正相关关系。     

北京汉石桥湿地水质分析与净化价值评价

通过对汉石桥湿地自然保护区核心区、东湖、西湖、游船区及微湿地开展水质监测、样品采集及实验室测定,对比分析了汉石桥湿地各区域水质,结果表明:湿地总氮、总磷的去除率为92.3%、79.0%,汉石桥湿地每年可净化总氮43.79t、总磷4.00t;利用替代费用法,计算出汉石桥湿地水质净化价值为1 684.03万元。     

川滇高山栎氮磷含量快速测定研究

根据文献已报道的植物全磷全氮测定方法,改进了AA3型连续流动分析仪对川滇高山栎枝叶全磷全氮含量测定的方法。结果表明:制备的氮磷标曲线性良好,相关系数均为1.0000,高于仪器的线性要求;全氮全磷标准偏差范围在0.017~0.038 mg/L和0.002~0.004 mg/L之间,变异系数范围分别是0.276%~0.776%和0.552%~0.919%,均小于1%(n=10),氮磷检出限分别为:N:0.0097mg/L,P:0.0092 mg/L,均满足仪器要求;氮磷空白加标回收率范围分别是94.2%~100.5%和96.8%~100.5%;经国家一级标准物质(GSV-2)验证,氮磷含量的测定值与标准值吻合,方法的相对准确度在99.22%~99.68%和99.76%~105.32%之间。因此,利用改进的AA3型连续流动分析仪测氮磷的方法测量川滇高山栎植物样全氮全磷的含量,具有准确且快速高效的优点。     

不同湿地植物对外源氮输入的响应

通过半人为控制模拟试验研究了土壤含氮量及黄花鸢尾、睡莲、芦苇、杞柳4种湿地植物含氮量不同月份的差异及土壤含氮量对植物含氮量和生物量的影响,分析了土壤含氮量与植物含氮量、生物量之间的相关关系.结果表明:当土壤施氮量为80g·m-2时,黄花鸢尾和睡莲含氮量达到最大,分别为(19.93±4.63)、(60.49±7.75)g·kg-1;种植黄花鸢尾和睡莲筛选池内土壤含氮量整体呈下降的变化趋势,杞柳和芦苇筛选池内土壤含氮量先降低后升高,9月份达最低值,分别为(0.89±0.14)、(0.82±0.15)g·kg-1;4种湿地植物生物量的变化存在一定的时间差异;湿地土壤含氮量对不同植物生物量的影响不同,睡莲和杞柳生物量与土壤含氮量之间呈线性相关.4种湿地植物含氮量与土壤含氮量之间存在一定的相关性,其中,杞柳、芦苇含氮量与土壤氮含量之间呈线性相关.     

Influence of tree shelters on seedling success in an afforested riparian zone

The restoration of a natural riparian ecosystem is a key component to improving water quality and restoring stream health in a disturbed watershed. The rate and degree of riparian restoration, and hence stream restoration, depends in part upon afforestation practices. Successful afforestation is determined largely by the rates of survivorship and growth of the tree species planted or recruited in a riparian zone. This study was part of a project involving the restoration of a channelized section of Wilson Creek located in the Bernheim Arboretum and Research Forest, Nelson County, Kentucky. Riparian restoration activities focused on reestablishing a native riparian corridor using American sycamore (Platanus occidentalis), green ash (Fraxinus pennsylvanica var. subintegerrima), and pin oak (Quercus palustris). This study evaluated techniques for improving the growth and survivorship of planted seedlings along Wilson Creek. Specifically, two tree shelter types (Tubex^® vs. continental mesh), with or without herbicide treatments, were compared. Additionally, the influence of these techniques on debris retention within the riparian zone was also examined. Results showed that use of tree shelters significantly increased the growth of seedlings (but not survivorship), provided physical protection especially during heavy flooding events, and accelerated woody debris retention. Both Tubex^® and continental mesh tree shelters were effective in enhancing seedling growth, with Tubex^® shelters yielding significantly better growth when combined with herbicide to control competing vegetation. Thus, the most cost effective choice may depend on the environmental setting and ability to combine the shelters with other growth enhancing treatments.     

塘渠-湿地复合系统治理农业面源污染研究

The effects of agricultural non-point source pollution control by pond-wetland combined system in Shenxi river basin of Anji county were studied based on nearly one-years experiment. The removal rate of total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) of the pond-wetland combined system was also studied with different inlet wastewater concentration and time. The results showed that the removal effect of TN, TP, and COD in pond-wetland combined system was fairly good. The removal rate of TN, TP, and COD in the system could respectively reach 96%, 98%, 82% when the TN, TP, and COD of inlet wastewater reach the highest point 33.3, 0.99, and 121.6 mg·L^-1. Generally, the removal effect of the system was better in plant growth season and higher concentration of inlet wastewater period.     

旱柳无性系在富营养化水体中的生长及去除氮磷能力

【目的】比较旱柳无性系的生长以及对水体中氮、磷去除效果,以筛选出处理富营养化水体效果较好的无性系。【方法】利用8个旱柳无性系在富营养化水体中进行静态培养试验,研究各无性系的形态特征、叶绿素相对含量指数、对营养元素的吸收以及对废水中氮、磷的去除效率。【结果】旱柳无性系在整个试验期间生长良好,无死亡现象。各无性系最终生物量、苗高和相对生长率有显著差异,其中,旱59和旱97整体表现最好。旱柳无性系对富营养化水体中氮、磷吸收较好,地上部分营养元素浓度较高。旱柳各无性系对总氮、氨氮和硝态氮的去除效率分别为87.17%96.94%、90.35%99.33%和66.66%88.19%,对总磷的去除效率为76.59%83.15%,无性系旱13总的去除效率最高。【结论】参试8个旱柳无性系均能在富营养化水体中正常生长,但各无性系在富营养化水体中的生长响应有较大差异。综合多个指标并结合长期野外试验观察,旱13、旱59、旱97是适合修复富营养化水体的较好材料。     

大兴安岭干旱阳坡土壤水分和养分变异性研究

在大兴安岭选择典型的干旱阳坡草丛和灌草丛植被,采用样线法研究植被类型间和地形部位间土壤水分、养分的空间分异特征。结果表明,草丛、灌草丛和山脊林地间土壤水分（SM）和养分（全碳（TC）、全磷（TP）、碱解氮（AN）、速效磷（AP）、速效钾（AK）、碳氮比（C/N））差异显著,均表现为山脊林地〉灌草丛〉草丛的格局;草丛和灌草丛不同地形部位土壤水分和养分（SM、TC、TP、AP、AK、和C/N）最大值均出现在山脊林地,但是在草丛坡下土壤水分和养分（SM、TC、TP、全钾（TK）和AP）高于坡上和坡中,而在灌草丛坡上土壤养分（TC、全氮（TN）、TP、AN、AP、AK和C/N）高于坡下和坡中。通过本研究得知,草丛和灌草丛土壤水分与磷素的缺乏是植被恢复的重要限制,地形和人为干扰改变了不同地形部位间土壤的水分和养分特征。     

Afforestation of a trace-element polluted area in SW Spain: woody plant performance and trace element accumulation

Trace element soil pollution can have ecotoxic effects on plants, which could negatively affect the restoration of a degraded area. In this work, we studied the revegetation success in different sites within a trace element-polluted area (Guadiamar River Valley, SW Spain). We analysed the survival and growth patterns of afforested plants of seven Mediterranean woody species, and their relation to soil pollution, over 3 years. We also analysed the trace element accumulation in the leaves of these species. The area was polluted mainly by As, Cd, Cu, Pb and Zn (soil total concentrations up to 250, 3.6, 236, 385 and 510 mg kg⁻¹, respectively). The woody plant performance was very different between sites and between species; in the riparian sites, plant survival rates were nearly 100%, while in the upland terrace sites species such as Quercus ilex and Ceratonia siliqua showed the lowest survival rates (less than 30%) and also the lowest relative growth rates. There were no significant relationships between plant performance and soil pollution in the riparian sites, while in the upland sites mortality, but not growth, was related to soil pollution, although that could be an indirect effect of different substrate alteration between sites. The accumulation of soil pollutants in the studied plants was low, with the exception of Salicaceae species, which accumulated Cd and Zn in the leaves above 1 and 200 mg kg⁻¹, respectively. We discuss the results with regard to the afforestation of trace-element polluted areas.     

Foliar resorption in Quercus petraea subsp. iberica and Arbutus andrachne along an elevational gradient

? The resorption of nutrients (mainly N and P) from senescing leaves may be a key component of adaptive mechanisms that conserve scarce nutrients. Resorption may be expressed in two ways as resorption efficiency (RE) which is the ratio of the resorbed amounts of nutrient losses during leaf senescence in relation to its prior amount deposited in leaves and resorption proficiency (RP) is the level to which nutrient concentration per unit leaf mass is reduced in senescent leaves.

? There is still much debate whether or not different life-forms (i.e. deciduous and evergreen species) show different foliar resorption patterns. Two sympatric species, namely Quercus petraea (Mattuschka) Liebl. subsp. iberica (Steven ex Bieb.) Krassiln. (deciduous) and Arbutus andrachne L. (evergreen) along an elevational gradient were compared with each other to determine whether or not nitrogen and phosphorus resorption efficiency and proficiency varies along the elevational gradient and which leaf parameters were as related to RE and RP.

? NRE was found to be rather low in Q. petraea subsp. iberica compared to other deciduous species. Similarly, PRE in A. andrachne was rather low compared to other evergreen species. Mean residence time (MRT) measures how long a unit of nitrogen (MRT_N) and phosphorus (MRT_P) is present in the plant. MRT_N and MRT_P were found to be considerably higher in A. andrachne compared to Q. petraea subsp. iberica. In both species, the foliar N/P ratio was below 14 along the elevational gradient and, according to this threshold value, N-limitation occurred in the study area. Although both species in the present study show incomplete resorption deciduous species was more proficient as compared to evergreen one due to low N and P concentrations in senescent leaves. Based on the significant correlations (p < 0.05 and 0.01) between MRT and foliar resorption, it can be concluded that MRT could interfere with the mechanisms controlling nutrient resorption.

     

庞泉沟自然保护区河岸林群落的土壤种子库特征

以人工拣种结合种子萌发法研究了庞泉沟自然保护区9种河岸林群落的土壤种子库特征,结果表明: 9种群落的土壤种子库密度间于684±108 - 2 696±266粒·m^-2,69.27% - 88.65%的种子留存于0 - 5 cm的层次,沙棘灌丛的种子库密度最大,乌柳灌丛最小;离河岸10 m和20 m处的种子库密度大于岸边、离河岸30 m和40 m处;种子库包含的40种植物以多年生草本为主,灌木和草本种多为耐干扰种,存在典型的湿地植物,但种子储量以先锋种白桦最丰;辽东栎无完整种子,白桦、华北落叶松、云杉和油松的种子活力保持期为1 - 2年,多数草本的种子活力保持期超过2年;按照群落土壤种子库的相似性,将群落划分为林分开始期、林分排除期、下层再现期和老熟期4个演替阶段。演替后期群落的种子库密度、丰度以及与地上植被的相似性都小于前期群落。土壤种子库是森林自然更新及种群恢复的重要基础,本文对于研究地区河岸林的保护和重建具有重要的理论意义。     

Plant-soil biodiversity relationships and nutrient retention in agricultural riparian zones of the Sacramento Valley,California

Forested riparian buffers in California historically supported high levels of biodiversity, but human activities have degraded these ecosystems over much of their former range. This study examined plant communities, belowground biodiversity and indicators of multiple ecosystem functions of riparian areas across an agricultural landscape in the Sacramento Valley of California, USA. Plant, nematode and soil microbial communities and soil physical and chemical properties were studied along 50-m transects at 20 sites that represented the different land use, soil and vegetation types in the landscape. Riparian zones supported greater plant diversity and nearly twice as much total carbon (C) per hectare compared to adjacent land managed for agricultural uses, but had generally lower soil microbial and nematode diversity and abundance. When woody plant communities were present in the riparian zone, plant diversity and species richness were higher, and soil nitrate and plant-available phosphorus levels were lower. Belowground diversity and community structure, however, appeared to depend more on plant productivity (as inferred by vegetation cover) than plant diversity or species richness. Greater plant species richness, nematode food web structure, total microbial biomass, woody C storage and lower soil nitrate and phosphorus loading were correlated with higher visual riparian health assessment scores, offering the possibility of managing these riparian habitats to provide multiple ecosystem functions.     

沙丘不同部位中间锦鸡儿人工林土壤养分特性及植物群落特征

以青海共和盆地沙丘上12年生的中间锦鸡儿人工林为研究对象,并以流动沙丘为对照,探讨在沙丘上建立中间锦鸡儿人工林后,沙丘部位对土壤养分含量以及植物群落的影响。在中间锦鸡儿人工林内沙丘的迎风坡中部、坡顶、背风坡中部和流动沙丘采集土壤样品,深度为0 5,5 10,10 20和20 50 cm。结果表明:与流动沙丘相比,沙丘3个部位中间锦鸡儿人工林0 20 cm的有机质、0 50 cm的全氮和全磷含量得到显著提高。迎风坡中间锦鸡儿人工林0 5 cm深度的土壤有机质和全氮、0 20 cm深度的全磷含量显著高于坡顶和背风坡。在沙丘上建立中间锦鸡儿人工林后,草本植物种类、数量和植被盖度增加,迎风坡草本植物盖度明显高于坡顶和背风坡。     

Vegetation community and soil characteristics of abandoned agricultural land and pine plantation in the Qinling Mountains,China

In order to determine the changes in the characteristics of the vegetation and soil following agricultural abandonment and compare the effects of different restoration approaches on ecosystem recovery, we studied the vegetation community and soil characteristics (nutrients, bulk density, water content and pH) of Pinus tabulaeformis plantations and abandoned croplands in different successional stages in the Foping National Nature Reserve, located in the Qinling Mountains, northwest China. The results indicated that natural vegetation and habitat could be restored via natural regeneration. These spontaneous restoration forests were characterized by high diversity, high soil fertility and rich unique species. The soil organic matter, total carbon, total nitrogen, available potassium, community cover, depth of litter, depth of humus and soil water content increased significantly with years after abandonment, while the total potassium, total phosphorus, available phosphorus, soil pH did not seem to change significantly with abandonment time. The soil mineral nitrogen (NH₄-N + NO₃-N) tended to increase during the first 50 years after abandonment and then decreased. The pine plantations tended to show a low level of biodiversity in tree and herb layer, but the shrub layer (including sapling) composition and diversity were similar to secondary forests. Although the pine plantation showed lower soil fertility, they did not seem to result in the habitat-degradation.