肇庆市某污水厂CASS工艺的调试与运行性能

对肇庆市某新建城市污水处理厂进行工艺调试,研究了其CASS系统对进水的处理效果。结果表明,调试阶段,进水CODCr、BOD5、NH4^＋-N和TP浓度分别为117．3-446．4mg·L^-1、60．5～225．9mg·L^-1、7．6～34．3mg·L^-1和1．85～5．49mg·L^-1,对应地,出水浓度分别为18．6-63．2mg·L^-1、8．0～29．2mg·L^-1、2．0-8．8mg·L^-1和0．22-0．83mg·L^-1。正常运行并优化工艺后,出水BOD5、NH4^＋-N和TP可达标排放。CASS池微生物数量丰富,正常运行阶段每克干污泥中,细菌、酵母菌和霉菌总数分别高达4．2×10^10±1．8×10^10CFU、2．5×10^7±1．8×10^7CFU和3．6×10^6±2．6×10^6CFU。     

蚊子花的组织培养与快速繁殖

1植物名称蚊子花（Lopezia cordata Hornem．）。 2材料类别茎段和顶芽。 3培养条件基本培养基为MS。（1）芽诱导培养基：1／2MS（MS大量元素用量减半）；（2）增殖培养基：MS＋6-BA0．2mg·L^-1（单位下同）＋NAA0．2；（3）生根培养基：I／2MS＋NAA0．5。以上培养基中均加入6g·L^-1琼脂和30g·L^-1蔗糖，pH5．9—6．0。培养室中温度为（24＋1）℃，光照时间为16h·d^-1，光照强度约为60μmol·m^-2·s^-1。     

食用稗成熟胚的组织培养及其细胞学特性

研究食用稗成熟胚培养因素的结果表明，愈伤诱导最适培养基为N6＋3．0mg·L^-12,4-D。N6基本培养基上的愈伤组织分化率较高；B5＋3．0mg·L^-12,4-D＋1．0mg·L^-16-BA的愈伤组织也具有较高的分化率。分化培养基N6＋2．0mg·L^-16-BA＋0．5mg·L^-1NAA利于绿芽分化；。茎尖部位的愈伤组织分化率比根的高。最佳生根培养基为1／2MS＋0．2mg·L^-1～NAA＋1．0g·L^-1AC。解剖和塑料半薄切片技术观察食用稗外植体的形态学和细胞学变化显示，胚根和胚轴主要形成非胚性愈伤组织，茎尖部位形成胚性愈伤组织。食用稗的器官建成途径倾向于以不定芽途径再生植株。芽原基为外起源，而根原基为内外起源兼有。     

不同坡度缓冲带径流污染净化效果及其最佳宽度

在前期资料调研、小试试验和基地选址的基础上，选择百慕大草皮构建了2％、3％、4％和5％四种不同坡度结构的滨岸缓冲带试验基地，开展径流污染物净化效果现场试验。结果表明，坡度与缓冲带径流悬浮固体颗粒物（SS）截留效果显著相关，19m长的2％坡度缓冲带末端的SS截留率达到84％，而5％坡度只有70％；2％坡度缓冲带末端渗流出水总氮（TN）、总磷（TP）平均浓度分别比5％坡度低1．63mg·L^-1和0．1mg·L^-1，在进水TP平均浓度范围为0．9—1．0mg·L^-1时，4种不同坡度试验带的渗流出水TP浓度均低于《地表水环境质量标准》（GB3838-2002）Ⅳ类水标准；通过计算，末端SS去除率为80％时，2％坡度需要的缓冲带最佳宽度为16．1m，5％坡度则为24．7m，两者相差达8．6m。     

'神马'菊花的离体保存及遗传稳定性

用添加不同蔗糖与甘露醇配比的培养基对切花菊品种＇神马＇（Jinba）试管苗进行离体保存,并对保存材料再生后代的遗传稳定性进行了研究.结果表明,在温度（23±2）℃、光照强度2 000～3 000 lx、光照时间12 h/d的培养条件下,MS＋0.3 mg·L^-1 6-BA＋0.1 mg·L^-1NAA培养基中分别添加10 g·L^-1蔗糖和10 g·L^-1甘露醇、10 g·L^-1蔗糖和20 g·L^-1甘露醇、20 g·L^-1蔗糖和20 g·L^-1甘露醇或30 g·L^-1蔗糖和10 g·L^-1甘露醇均能使菊花试管苗连续保存12个月,其中10 g·L^-1蔗糖和20 g·L^-1甘露醇、20 g·L^-1蔗糖和20 g·L^-1甘露醇组合处理保存12个月后成活率较高,分别达到50.00%和60.00%,且均保持最高的增殖倍数2.67.保存12个月的试管苗在增殖、生根培养基上均能正常恢复生长,且其再生后代的田间生物学性状、过氧化物酶（POD）及酯酶（EST）同工酶酶谱、ISSR扩增图谱与对照株无差异,保持了良好的遗传稳定性,说明利用上述方法保存＇神马＇种质是可行的.     

刺五加腋芽培养中抗褐化初探

研究刺五加腋芽分化生长过程中褐化现象的结果表明，以75％的酒精消毒40s，0．1％的升汞灭菌8min能较好地抑制褐化现象；1000mg·L^-1维生素C的抑制作用较为明显；WPM＋1．0mg·L^-16-BA＋0．1mg·L^-1NAA培养基的褐化现象最轻：15mg·L^-1蔗糖、5d暗处理和15d转瓶一次都能在一定程度上抑制褐化。     

大旗瓣凤仙花的组织培养与快速繁殖

1植物名称 大旗瓣风仙花（Impatiens macrovexilla Y．L．Chen）。 2材料类别 茎上侧芽。 3培养条件 增殖培养基：（1）MS＋6-BA1．5mg·L^-1（单位下同）；继代和生根培养基：（2）MS＋6-BA1．0。以上培养基中均加入30g·L^-1蔗糖和5．5g·L^-1琼脂，pH5．8。培养温度（25±3）℃，光照时间12h·d^-1，光照强度40～50gmol·m^-2·s^-1。     

石龙尾(Limnophila sessiliflora BI.)的组织培养与快速繁殖技术研究

以石龙尾（Limnophila sessiliflora BI．）沉水枝带节茎段为外植体进行离体培养，研究外植体灭菌方法以及培养基中不同生长调节剂的浓度对其增殖、生根的影响。结果表明：以0．1％的HgCl2为灭菌剂，采用4min＋4min、间歇4h的间歇灭菌法，可以获得成活的无菌外植体15％；在1／2MS＋6．BA2．0mg·L^-1＋NAA 0．1～0．2mg·L^-1的增殖培养基上培养35d，试管苗的增殖系数可达30．8以上；在1／2MS＋6-BA 0．3mg·L^-1＋NAA 0．5mg·L^-1的生根培养基上培养28d后，可获得具3～5个侧枝的生根苗，平均每株生根数4．8条；炼苗后移植成活率100％。     

荷叶椒草的组织培养和植株再生

1植物名称 荷叶椒草（Peperomia polybotryaH．B．K）。 2材料类别 茎段。 3培养条件 不定芽诱导培养基：（1）MS＋6．BA3mg·L^-1（单位下同）；不定芽增殖培养基：（2）MS＋6-BA0．5＋KT0．5；壮苗培养基：（3）1／2MS＋0．5g·L^-1活性炭。     

欧洲小叶椴的胚培养与快速繁殖

1植物名称欧洲小叶椴（Tilia cordata Mill．）。 2材料类别成熟胚。 3培养条件（1）／3动培养基：MS＋6-BA2．0mg·L^-1（单位下同）＋NAA0．1；（2）增殖培养基：MS＋6．BA1．0＋NAA0．1；（3）壮苗生根培养基：1／2MS＋IBA1．0＋NAA0．3。以上培养基均加入0．55％琼脂和20g·L^-1。蔗精，pH5．8-6．0。培养温度为（25±2）℃；光照培养时间12h·d^-1，光照强度40．50μmol·m^-2·s^-1。     

Organic matter and nutrient dynamics of the forest and forest floor in the Hubbard Brook forest

Summary The forest floor is a major reservoir of organic matter and nutrients for the ecosystem and as such it influences or regulates most of the functional processes occurring throughout the ecosystem. This study reports on the nutrient and organic matter content of the forest floor of the Hubbard Brook Experimental Forest during different seasons and attempts to correlate results from studies of vegetation, litter, decomposition, stemflow, throughfall, and soil. An organic matter budget is presented for an undisturbed watershed.Average weight of the forest floor on an undisturbed watershed ranged from 25,500 to 85,500 kg/ha. The weighted watershed average was 46,800 kg/ha. Although the F and H horizons did not vary significantly with time, the L horizon increased significantly during the period June to August largely as a result of a severe hail storm. The order of abundance of elements in the forest floor was N;CaFe>S>P>Mn>K>Mg>Na>Zn>Cu. The concentrations of Ca, K, and Mn decreased with depth in the forest floor while N, P, S, Na, Fe, Zn, and Cu concentrations increased. N:P ratios were similar in decomposing leaf tissue, the forest floor, litterfall, and net stemflow plus throughfall suggesting a similar pattern of cycling. S was proportional to N and P in decomposing leaf tissue, the forest floor, and litterfall. Net stemflow and throughfall were affected by a relatively large input of SO₄=-S from the atmosphere. Residence times for elements in the forest floor were affected by inputs other than litterfall (precipitation, stemflow, and throughfall). Calculation of residence times using all inputs caused smaller values than if litterfall alone was used. While all residence times were reduced, the major differences occurred for K, S, and Na. N and P showed relatively long residence times as a result of retranslocation and immobilization by decomposers. The slow turnover rate because of the strong demand and retention by all biota must account for the efficiency of the intrasystem cycling process for N and P. K showed the shortest residence time. A rapid and efficient uptake of K by vegetation seems to account for the efficient cycling of this element. The patterns of nutrient cycling are several depending on the chemical properties of the forest floor, and nutritional requirements of the biota.This is contribution No. 67 of the Hubbard Brook Ecosystem Study. Financial support was provided by the National Science Foundation.     

Restoration of the understorey layer of recent forest bordering ancient forest

Abstract. Recently established forests are commonly characterized by an impoverished understorey. Restoration is mostly based on spontaneous secondary succession, but little is known about the time period needed to achieve a community species pool with species composition equal to that of ancient forests. Vegetation in transects of 197 plots in 13 recent forest stands contiguous to the Meerdaalwoud ancient forest complex was surveyed. The recent forest stands ranged in age from 36 to 132 yr. The community species pool was described with an ecological, functional and phytosociological approach and based on groups derived from a CCA. Differences in community species pool between age classes of recent forest stands were analysed. During establishment of a new forest competitive species, forest edge species and species with high Ellenberg values for light and nitrogen and a more persistent seed bank will dominate the understorey. After 90 yr of succession the cover by these species decreases and reaches equal values to ancient forest after ca. 105 yr. A large number of forest species will be able to colonize the forest in less than 90 yr. Some typical forest species, however, have very low colonization rates and still have low cover in recent forest more than 105 yr old, so that complete restoration of the understorey requires a time period of over a century. Anthropogenic introduction of forest plant species may reduce the time required for ancient forest vegetation equality.     

火对森林土壤的影响

林火是林地上自由蔓延的火,主要有计划火烧(控制火烧)和野火2种类型.火烧的严重程度决定了火灾的效果及其影响的持续时间.火能够通过燃烧有机质和改变粘土矿物来影响土壤结构,导致土壤容重增加和持水能力降低.长期来看,火烧引起土壤有机质减少.火烧之后土壤温度和pH值的升高会促进土壤呼吸,而微生物数量的减少、根系的死亡和可分解物质的减少则减弱土壤呼吸.林火消耗了森林的枯落物层,通过氧化、挥发、灰分颗粒对流、淋溶等途径减少了森林土壤的养分含量.火灾对土壤生物有重要影响,火灾引起的高温可直接杀死土壤微生物,同时通过改变土壤的各种理化性质及林地微环境,间接影响土壤微生物生存和群落的组成.火对土壤动物的影响显著小于对土壤微生物的影响,原因是前者具有更高的灵活性来逃避火灾.中低程度火烧主要通过土壤环境变化间接影响土壤酶,而严重火烧则通过高温直接使其变性.今后应开展跨学科的森林火灾长期研究,加强对火烧后土壤动物、微生物和生态系统之间相互关系的研究,注重计划用火、火灾对土壤有机碳、土壤养分库的稳定、土壤斥水性、水土流失强度和生物多样性影响方面的研究.     

Changes in the forest floor of Canadian southern boreal forest after disturbance

Abstract. The concentrations and contents of organic matter and nutrients in organic deposits on the forest floor were estimated along a 231-yr chronosequence following fire at the southern limit of the boreal forest in eastern Canada. The sampling design was stratified to take into account the variability related to the presence of the principal tree species as well as to the presence of large gaps created by a recent spruce budworm (Choristoneura fumiferana) outbreak. The forest floor showed a steady accumulation of organic matter and total nutrients with time-since-fire and a 50 % decrease in the concentrations of available P and K, but not N (as determined by aerobic incubation). The increase in forest-floor weight was accompanied by an increased storage of available N, Ca and Mg. The availability of N and Ca was more strongly affected by tree species and gaps than by time-since-fire. A high N-availability was observed under Betula papyrifera and in gaps, while high a Ca-availability was found near Populus tremuloides and Thuja occidentalis. In old sites, the forest floor of gaps, created by a recent spruce budworm outbreak, had a necromass similar to that of a young forest, but the low concentrations of available P and K of an old forest.     

Silvichemicals from the forest

Tree species vary in properties because of the chemical nature of their respective extractive components. Extractives play an important role in ever increasing silvichemical industries. Numerous industrial extractive chemicals derived from wood and bark are discussed here.     

Enhancing the biodiversity of Scotland's forest resource through the development of a network of forest habitats

Scottish Natural Heritage, the statutory conservation agency, is considering the desirability and feasibility of developing a network of woodland habitats to redress the long term trend of fragmentation and isolation. Woodland conservation has long been based on site protection, but recent changes in policy, attitude and practice have opened up the possibility of recreating native forest cover on a much larger scale. The ECONET approach appears to have much to offer as the basis for enhancing the biodiversity of Scotland's forest resource. A network could be developed from existing woods to form a Scotland-wide network of Core Forest Areas and major landscape links, largely associated with major valleys. To achieve this, existing concentrations of woodland would be extended into poorly wooded districts. Many vulnerable wildlife species are likely to benefit, and there would be other benefits for recreation, landscape and timber production.     

林隙干扰对森林生态系统的影响

林隙干扰通过改变森林微生境异质性和群落演替进程,对森林物种组成、林分结构和系统功能产生重要影响。本研究评述了有关林隙干扰对森林生态系统影响的最新研究进展,从物种生物学特性和环境因素两个方面分析了林隙干扰对森林物种组成变化的影响规律,基于群落组件和群落架构阐述了林隙干扰对森林结构的作用关系,梳理了林隙干扰对森林生态系统功能的影响机制。基于已有研究的分析和目前森林生态系统经营亟需解决的问题,提出未来研究所需关注的重点领域和问题: 林隙面积阈值确定方法;林隙闭合机制;林隙干扰对森林生态系统过程的影响;林隙干扰与森林生产力的关系。林隙干扰在促进物种更新和提升森林结构复杂性等方面具有优势,因此本研究可为我国低产低效人工林改造提供科学依据。     

Beyond the tropics: forest structure in a temperate forest mapped plot

Question: How do the diversity, size structure, and spatial pattern of woody species in a temperate (Mediterranean climate) forest compare to temperate and tropical forests? Location: Mixed evergreen coastal forest in the Santa Cruz Mountains, California, USA. Methods: We mapped, tagged, identified, and measured all woody stems (≥1 cm diameter) in a 6‐ha forest plot, following Center for Tropical Forest Science protocols. We compared patterns to those found in 14 tropical and 12 temperate forest plots. Results: The forest is dominated by Douglas‐fir (Pseudotsuga menziesii) and three species of Fagaceae (Quercus agrifolia, Q. parvula var. shrevei, and Lithocarpus densiflorus), and includes 31 woody species and 8180 individuals. Much of the diversity was in small‐diameter shrubs, treelets, and vines that have not been included in most other temperate forest plots because stems <5‐cm diameter had been excluded from study. The density of woody stems (1363 stems ha^?1) was lower than that in all but one tropical plot. The density of large trees (diameter ≥30 cm) and basal area were higher than in any tropical plot. Stem density and basal area were similar to most other temperate plots, but were less than in low‐diversity conifer forests. Rare species were strongly aggregated, with the degree of aggregation decreasing with abundance so that the most common species were significantly more regular than random. Conclusions: The patterns raise questions about differences in structure and dynamics between tropical and temperate forests; these need to be confirmed with additional temperate zone mapped plots that include small‐diameter individuals.     

Effects of forest clear-cutting and soil disturbance on the biology of small forest brooks

As a part of the larger Nurmes research project, we studied the effects of clear-cutting and soil disturbance (ditching, ploughing, mounding) on the biology of small forest brooks. After these forestry activities, incoming light, temperature, and nutrient content of the water increased significantly. Mean algal biomass peaked during the first summer after clear-cutting. During the first year following soil disturbance, algal biomass initially decreased because of turbidity, but began to rise again as suspended solids in the water decreased in the summer months. Species composition changed, too; after clear-cutting, Cryptomonas and Chlamydomonas species increased their densities (48% of the algal biomass) and following soil disturbance, the species numbers and densities of Conjugatophyceae (52% of the algal biomass) were higher than before. Canonical correspondence analysis suggested that increased nutrient levels and acidity were the main factors behind the changes in the flora following clear-cutting. The most important effect of soil disturbance was the increased water temperature. Effects of forest clear-cutting on algal productivity in the brooks remain evident at least for three years and those of soil disturbance for an even longer period. Restricted clear-cutting, with a protective zone left uncut around the brooks, appears to reduce the effects.