Above-ground biomass structure of a Chusquea tessellata bamboo páramo,Chingaza National Park,Cordillera Oriental,Colombia

The present study was carried out in the bamboo (Chusquea tessellata) páramo of Parque Natural Nacional de Chingaza, Eastern Cordillera, Colombia from December 1987 to April 1988. Above-ground biomass structure of bamboo páramo was quantified in 16 plots. These data are compared with previous results on above-ground biomass structure of bunch-grass (Calamagrostis spp.) páramos.The total (non-living and living) above-ground biomass of a Chusquea tessellata bamboo páramo was low (2,625 g DW · m^–2) compared to bunch-grass páramo. Nevertheless, higher values of standing living biomass and litter are found in the bamboo páramo due to the leaf shed of the bamboo. The thick litter layer may inhibit germination and growth of nearby plants.Maximum biomass is found near the ground surface. Cumulative LAI (In transformed) and height in the bamboo vegetation are related parabolically for Chusquea tessellata and linearly for bunch-grass due to differences in leaf distribution. The mean bifacial LAI of living Chusquea tessellata leaves is 2.2 m² · m^–2, whereas it is 2.5 m² · m^-2 for all Poaceae.     

豫西刺槐能源林的热值动态

对豫西丘陵区5个无性系刺槐苗期的不同器官的干重热值、去灰分热值和灰分含量及生长量和生物量进行了测定。结果表明:5个无性系刺槐苗期的生长节律不同和各器官的积累速度不同,最后一季干物质量排序为3-I＞83002＞84023＞8044＞8048;5个无性系刺槐苗期的各器官中干重热值和去灰分热值的排序存在差异,8044的叶和枝的干重热值和去灰分热值平均最大,分别为19.31、21.18 kJ/g和18.00、19.39 kJ/g,8048干的干重热值和83002干的去灰分热值平均最大,分别为18.72、19.12 kJ/g,83002皮的干重热值和去灰分热值平均最大,分别为17.77、19.29 kJ/g。整体上标准木单位质量的干重热值表现为先升后降,83002、3-I、84023的生长潜能大,单位面积上的热值表现为无性系83002、3-I、84023最大。     

华南十种桉树的热值与灰分含量比较

桉树是林业生物质能源的原料之一,了解桉树的热值和灰分含量能为合理利用桉树能源林提供理论参考。该研究采用热量计和马福炉对华南尾巨桉等10种桉树的不同器官进行热值和灰分含量测定。结果表明：10种桉树树叶、树枝、树根、树干和树皮的干质量热值、去灰分热值分别为15.10~21.06 kJ.g-1和16.50~22.11 kJ.g-1,器官的平均干质量热值、去灰分热值以树叶最高(19.50和20.56 kJ.g-1)、树皮的最低(17.32和18.09 kJ.g-1),说明树叶所含的高能有机物质比其它器官多;不同器官的干质量热值与去灰分热值在不同品种中的大小排序不完全一致。灰分含量在0.14％~8.5％之间,器官平均的灰分含量以树叶最高(5.13％)、树干最低(0.30％),说明树叶所含的矿质元素较多。不同器官的热值与灰分含量均差异显著(P<0.05)。植株个体的干质量热值与去灰分热值均以尾叶桉最高(18.99和19.18 kJ.g-1),以托里桉最低(17.53和17.86 kJ.g-1);灰分含量则以托里桉最高(1.90％)、巨桉最低(0.61％)。相关分析结果表明,灰分含量与干质量热值、去灰分热值存在一定的负相关,但未达显著水平;干质量热值与去灰分热值呈极显著的正相关关系(P<0.01)。由于理想的植物燃料应具备热值高与灰分含量低的特点,结合该研究的结果分析,托里桉作为燃料资源利用不理想,以尾叶桉较为适宜。     

The growth form composition of plant communities in the ecuadorian páramos

A growth form classification for the plants of the Ecuadorian páramos is proposed, consisting of ten forms: stem rosettes, basal rosettes, tussocks, acaulescent rosettes, cushions and mats, upright shrubs, prostrate shrubs, erect herbs, prostrate herbs, and trailing herbs.The growth form composition of 192 samples of páramo vegetation from twelve different regions in Ecuador was analysed using multivariate techniques to determine physiognomic types. The distribution of growth forms was significantly related to altitude, rock cover, bare ground and to measures of disturbance and exposure.The dominant growth forms in all the samples belonged to one of Hedberg's (1964) five types, but other forms were also significant components of the vegetation. The majority of Ecuadorian páramo vegetation showed a relatively consistent growth form composition, dominated by tussocks. The accompanying growth forms were mostly acaulescent rosettes, cushions, upright shrubs, prostrate shrubs, erect herbs and prostrate herbs, sometimes with stem rosettes, basal rosettes or trailing herbs.At higher altitudes, the dominance of tussocks was reduced. At first, acaulescent rosettes became dominant, but higher still their dominance was shared with cushions. At the highest altitudes of all, where plant cover was thin, no single growth form was dominant. In other locations where plant cover was sparse, once again no single growth form was dominant. In humid páramos, stem rosettes were co-dominant with tussocks or erect herbs. Basal rosettes, erect herbs and prostrate herbs were locally co-dominant at higher altitudes.The growth form composition of the Ecuadorian páramos showed similarities with other tropical alpine regions, though no comparable quantitative data for these regions are available yet. The quantitative determination of growth form composition may also lead to a better understanding of community structure and the mechanisms which govern it.     

滨海沙地木麻黄(Casuarina equisetifolia)人工林细根养分与能量动态

2005年1月到2005年11月对福建省惠安县赤湖林场不同林龄木麻黄人工林细根养分和能量的季节动态进行了观测,结果表明:(1)6种元素的含量在不同林龄木麻黄细根中都具有明显的季节变化。各林龄细根的N含量一般在冬夏季节较高,且死细根的N浓度高于相同林龄的活细根,除12林龄活细根P浓度在7月份有最大值外,其他各林龄活、死细根在一年中呈波动性下降,K含量在冬季较高,而在其他季节变化幅度不大,除5林龄活细根和18林龄死细根在3月份和7月份有两个峰值外,其他林龄细根Ca含量随季节变化较小,Mg含量随季节变化总体呈下降趋势,而在11月份上升;各林龄C则呈波浪形变化;(2)随着林龄的增大,细根N、P、Mg含量的变化模式相似,都呈先增加,后降低,再增加的趋势,K和Ca含量变化趋势相似,但变动幅度存在差别,C则呈波浪形变化;(3)随着季节的变化,灰分、干重热值和去灰分热值呈"V"形变动,一年中都存在两个峰值,分别在3月份和7月份或9月份;(4)灰分、干重热值和去灰分热值随林龄的增大表现为波浪形增加。由此可见,不同森林类型的细根养分和能量动态具有季节和林龄的特殊性,在进行整个地区森林生态系统物质循环和能量流动研究时,应考虑不同森林类型的特性。     

Angiosperm flora and biogeography of the páramo region of Colombia,Northern Andes

Páramo is the neotropical high elevation ecosystem in the northern Andes and Central America consisting of multiple dissected open areas above 3000 m a.s.l. Complex evolutionary processes that occurred within these ecosystems gave rise to a unique tropical Andean flora. Previous phytogeographical classifications for Colombian páramos have been based on subjective assessments of species distributions. However, a detailed floristic analysis highlighting affinities between páramo regions in Colombia has not yet been proposed. The aim of this study is to provide an analytical scenario for the patterns of regional plant diversity in a hierarchical framework based on the biogeographical history of the páramos, based on 30 localities of the Colombian páramos. Parsimony analysis of endemicity (PAE) and Jaccard similarity indices were applied to a presence/absence data matrix of páramo angiosperm species. Altitudinal distribution of species was used to determine the percentage of the páramo flora endemic to this ecosystem. Genera are shared among páramos, whereas species composition is highly endemic. 86% of the páramo angiosperm plant species is endemic to this ecosystem. The Colombian Páramo areas can be grouped using PAE into five biogeographical units, based on angiosperm species composition. These are: (1) Páramos de la Cordillera Oriental; (2) Páramos de la Cordillera Central and Macizo Colombiano; (3) Páramos de Antioquia; (4) Páramos del Norte; (5) Páramos de la Cordillera Occidental.     

布迪椰子不同器官热值的季节变化研究

对布迪椰子的幼叶、成熟叶、叶柄和根在不同季节的干重热值、去灰分热值和灰分含量进行了研究,结果表明:干重热值四个季节的平均值为成熟叶(20.65kJg-1)>幼叶(19.84kJg-1)>根(19.55kJg-1)>叶柄(18.77kJg-1),秋季的干重热值明显高于其它三个季节的干重热值,冬季的干重热值最低,去灰分热值与干重热值的变化趋势基本相同。灰分含量四个季节的平均值为根(5.14%)>叶柄(4.33%)>幼叶(4.21%)>成熟叶(3.97%)。成熟叶的灰分含量一直维持在比较低的水平,而幼叶的在秋季明显下降,在冬季明显上升,幼叶灰分含量的季节变化趋势与成熟叶的相同,叶柄灰分含量在冬季明显低于根部。布迪椰子这种不同器官在不同季节的热值和灰分的变化规律显示其具有较强的耐寒适应性。     

闽江河口湿地植物与土壤灰分及其影响因子分析

以闽江河口鳝鱼滩湿地生长的芦苇(Phragmitesaustralis)和互花米草(Spartina alterniflora)为研究对象,并对相应的36个土壤剖面进行取样分析,揭示它们的(厂火)分含量分布特征,并对其影响因子进行分析。研究结果表明:闽江河口鳝鱼滩湿地芦苇和互花米草各个器官(厂火)分含量的差异性明显,芦苇各部位(厂火)分含量的平均值大于互花米草;芦苇和互花米草湿地土壤(厂火)分含量的垂直分布较为类似,芦苇湿地土壤(厂火)分合量略高于互花米草湿地土壤(厂火)分含量,但两种植物土壤(厂火)分含量的差异并不显著;芦苇和互花米草湿地土壤(厂火)分含量与土壤有机碳有极其显著的负相关关系,与土壤含水量的相关性也较明显;从单一的植物类型来看,互花米草湿地土壤(厂火)分含量与容重、碳含量、含水量和盐度呈显著的相关关系,芦苇湿地土壤(厂火)分含量与土壤pH值有明显的正相关关系。     

福州鼓山季风常绿阔叶林及其林缘几种植物叶热值和营养成分

研究了福州鼓山次生的南亚热带季风常绿阔叶要及其林缘不同层次１３种植物叶热值、灰分含是及营养成分。结果表明：群落的不同层次平均灰分含量从低到高依次是乔木层（６．８％）,草本层（８．５％）、灌木层（１０％）;平均含灰分热值（ＧＣＶ）从低到高低次是草本层（１６．８９ＫＪ／ｇ）、灌木层（１７．７５ＫＪ／ｇ）、乔木层（１９．７９ＫＪ／ｇ）;平均不含灰分热值（ＡＦＣＶ）从低到高依次是草本层（１８．５５ＫＪ／ｇ     

Annual,daily and diurnal variations of Urticaceae airborne pollen in Málaga (Spain)

In the Mediterranean area, Urticaceae pollen, together with the pollen of olive and grasses, are the aeroallergens with the highest incidence in the population. From October 1991 to September 1993, with the aid of a Burkard spore-trap, we carried out a study on the Urticaceae pollen content in the atmosphere of Málaga, a seaside resort situated in the Costa del Sol (southern Spain). In Málaga, the Urticaceae pollen season is very long and their pollen grains are detected throughout the year. However, peaks were recorded in March and April and the variables most influencing concentration were maximum air temperature, sunshine hours and relative humidity. Diurnal patterns show that peaks occur generally from 10:00 h to 16:00 h when the temperature reaches its highest values.     

Metabolic disturbances innicotiana glauca,a symptomless

Metabolic disturbances inNicotiana glauca, a symptomless carrier of potato witches’ broom were studied. The dry weight content of leaves of diseased plants was slightly decreased, that of the stems increased. The ash content in the dry weight of the whole diseased plant was decreased by 11%. Contrary to tomato plants which had shown considerable disproportions in the distribution of metabolites among the individual organs investigated (ULRYCHOVÁ, LIMBERK 1964), the content of the total nitrogen and of the individual nitrogen fractions of both leaves and stems of diseasedNicotiana glauca were decreased. The content of glutamine was increased in both organs in spite of the decrease of ammonia nitrogen by nearly 30% in both cases. The most striking disturbance found in the diseased plants ofNicotiana glauca was the 67% increase of a low-molecular phosphorus fraction (P extractable with 0-2N HCIO₄) in the leaves. This result agrees with that found in diseased tomato plants and may be primarily associated with the virus infection. The content of all other phosphorus fractions of both leaves and stems was decreased.     

Floral,climatic and soil pH controls on leaf ash content in China's terrestrial plants

Aim To investigate broad‐scale patterns of plant leaf ash content and their possible causes in China. Location Mainland China and Hainan island, with the geographic ranges for the data used from 18.7° N to 49.2° N and 76.0° E to 128.3° E. Methods By analysing a data set of 2022 leaf samples, involving 704 species of terrestrial plants. Results Leaf ash content increases with increasing latitude at an average rate of 2.7 mg ash g^?1 dry weight per degree latitude from south to north of China. Plant functional group shows a more powerful influence on the spatial variation in leaf ash than soil pH and climate. Fast‐growing species or those with leaves with a short life span have higher leaf ash than slow‐growing species or those with a long leaf life span. Plants from alkaline soils have higher leaf ash than those from acid soils (39.5 mg g^?1 increase in leaf ash content per unit increase of pH). Increasing precipitation significantly reduces leaf ash (with a mean rate of 4.8 mg g^?1 for every 100 mm rainfall), whereas the effect of temperature appears to be nonlinear. Main conclusions This study shows a significant latitudinal trend in leaf ash content in China. This geographic pattern is possibly shaped by the floral, edaphic and climatic factors that control the biogeochemical cycling of plant minerals. The results suggest that leaf ash content is a useful biogeographic indicator that can be used to explore the complex interactions between plants and the environment.     

夏蜡梅及其主要伴生种叶的灰分含量和热值

分别于2006年7月、10月和2007年4月,对全光照、林缘和林下3种光环境下夏蜡梅及群落中35种主要植物叶的灰分含量和去灰分热值进行测定,分析它们在光合作用中对太阳能的固定和积累能力。不同光环境下夏蜡梅叶灰分含量的大小顺序都是全光照＞林缘＞林下,10月3种光环境下夏蜡梅叶灰分含量均高于4月和7月,均差异显著。4月、7月和10月,林下和全光照环境下的叶去灰分热值呈先下降后上升的趋势,而林缘中叶去灰分热值却逐渐下降。群落各层植物的灰分含量大小顺序为草本层＞灌木层＞间层＞乔木层,夏蜡梅灰分含量略低于灌木层灰分含量的平均值;各层次植物平均去灰分热值大小顺序为乔木层＞灌木层＞草本层＞间层,夏蜡梅平均去灰分热值低于间层。多数植物不同季节叶的灰分含量、去灰分热值均以10月最高。     

Fly ash effect on improving soil properties and rice productivity in Korean paddy soils

Paddy soils in Korea generally require the addition of Si to enhance rice productivity. Coal combustion fly ash, which has a high available Si content and alkaline pH, was selected as a potential source of Si in this study. Two field experiments were carried out to evaluate rice (Oryza sativa) productivity in silt loam and loamy sand soils to which 0, 40, 80, and 120 Mg ha(-1) of fly ash were added with 2 Mg ha(-1) Si as a control. Fly ash increased the soil pH and available Si and P contents of both soils. The amount of available B increased to a maximum of 2.57 mg kg(-1), and the B content of the rice plants increased to a maximum of 52-53 mg kg(-1) following the addition of 120 Mg ha(-1) fly ash. The rice plants did not show toxicity effects. The highest rice yields were achieved following the addition of around 90 Mg ha(-1) fly ash. The application of fly ash increased Si, P and K uptake by the rice plants, but did not result in an excessive uptake of heavy metals in the submerged paddy soil. In conclusion, fly ash could be a good supplement to other inorganic soil amendments to improve the nutrient balance in paddy soils.     

The effects of grazing and burning on soil and plant nutrient concentrations in Colombian páramo grasslands

The impact of extensive livestock farming on the physical and chemical characteristics of the volcanic soils and on the nutrient status of green plant tissues of neotropical alpine grasslands (páramo) is studied. Soil and plant samples were taken over a one-year period at five sites with different agricultural (grazing and burning) management. In the undisturbed páramo ecosystem, soil moisture (50–250%) and organic matter content are high (7–27%) and decomposition (11–35% yr^-1) and element concentrations are low. Low temperatures (max < 10°C) and phosphorus fixation by the soil (5 mg P g^-1 soil) determine the low mineralization and turn-over rates.Multivariate analysis of laboratory results indicates that the season of sampling and the agricultural practice are the most important explanatory factors for variation of soil characteristics. After long-term heavy grazing, soils have a higher bulk density and a lower moisture content. The outcome of a litterbag experiment confirms the hypothesis of higher decomposition rates at grazed sites. In the intermediate (wet-dry) season, conditions were somewhat better for plant growth but the system remained nutrient limited.Surprisingly, no relation between soil density, moisture or carbon content and concentrations of available nutrients in the soil is found. This is supported by the rather uniform nutrient concentrations in green plant tissue among the sites. It is concluded therefore that the effect of burning and grazing on páramo soils is principally restricted to physical characteristics, and that differences in chemical characteristics of the soil do not cause differences in vegetation structure between grazed, burned and undisturbed sites.The Netherlands Centre for Geo-ecological Research, ICG.     

Effects of boron on growing pullets

The effects of dietary boron on bone ash content and on the ultimate shear force, stress, and fracture energy of the tibia, femur, humerus, and radius from white Leghorn pullets were investigated. There was a significant increase in the shear force of the tibia and femur for pullets supplemented with 50 and 100 mg/kg of dietary boron. There was a significant increase in the shear stress of the tibia at 50 and 100 mg/kg of boron, and also an increase in shear fracture energy at 50 and 100 mg/kg boron for the femur. Tibia bone ash content increased significantly at 50, 100, and 200 mg/kg boron with the highest value at 50 mg/kg. Even though there was not a significant increase in body wt at 50 and 100 mg/kg boron, the pullets fed these supplements were consistently heavier than the control group.     

青海锡铁山矿区铅、锌的植物地球化学特征及其与矿的关系

 通过青海锡铁山铅、锌矿区植物群落和植物中铅,锌含量特征的调查研究表明：该区植被为荒漠植被类型。矿带上的植物群落与非矿带上的相比较,群落中种属数目更少,覆盖度更低,植物生长更低矮。植物灰分中的锌含量(平均)为125.9—1144ppm。膜果麻黄(Ephedra przewalskii)含量最高,变化范围最大,为86.11—5871.88ppm。植物中的铅含量为31.32—1129.6ppm。黑柴(Sympegma regelii)含量较高,变化最大,平均为746ppm,极值为14.3—5561.70ppm。在矿带上含量最高,非矿带对照区含量最低。植物及其生长的土壤中金属元素含量之间的关系,无论是铅还是锌含量都有很好的线性关系。膜果麻黄、黑柴、优若藜(Eurotia ceratoides)和中亚紫菀木(Asterothamnus centrali-asiaticus)等植物相关系数均达显著相关水平(α≤0.05)。 这在植物地球化学勘探上是非常有用的。例如中亚紫菀木和琵琶柴(Reaumuria soongorica)中铅的植物地球化学异常,准确地圈出了铅、锌矿的位置,衬度高,异常范围与矿化区基本吻合。     

我国淡水优质草食性鱼类的营养和能量学研究 Ⅱ.草鱼、团头鲂对七种水生高等植物的最大摄食量和消化率的测定

作者采用常规生化分析法测定草食性鱼类天然食料(七种水生高等植物)的生化成分和能值。在实验室特定条件下测定了草鱼和团头鲂的系列体重组对七种水生高等植物的最大摄食量和消化率。1.七种水生高等植物的生化成分的含量和能值的分析结果表明,菹草、黄丝草、聚草、苦草、小茨草、轮叶黑藻和紫背浮萍的水分百分含量范围为80.85—92.72%、蛋白质为1.69—4.96%、脂肪为0.35—1.09%、灰分为0.98—2.6%、纤维素为0.66—2.17%、无氮浸出物为2.3—9.95%。七种水生植物的蛋白质均含有常见十七种氨基酸,包括鱼体必需氨基酸九种和非必需氨基酸八种。其中菹草的氨基酸含量最高(36.63mg/g 湿重)、苦草最低(12.92mg/g 湿重);菹草的能值最高(3.36KJ/g 湿重)、小茨藻最低(1.28KJ/g 湿重)。2.草鱼、团头鲂对七种水生植物的最大摄食量(Y,g/24h)及消化率(Y,%)与鱼体重(X,g)相关显著,关系式为 Y=aX~b。从结果表明,随着鱼体重的增加,鱼对七种食料的相对摄食量下降(绝对摄食量上升),消化率提高。草鱼的最大摄食量一般比团头鲂高,而消化率一般比团头鲂低。       

Pubescence,floral temperature and fecundity in species of Puya (Bromeliaceae) in the Ecuadorian Andes

Summary The effects of inflorescence pubescence on floral temperatures and fecundity were examined in four species of Puya in the Ecuadorian Andes. These species span an elevational range from 1,980–4,000 m and comparisons among these species showed that pubescence production increases significantly with elevation. Flower temperatures of glabrous or slightly pubescent species of Puya from lower elevations closely tracked air temperature, while those of the pubescent páramo species did not. Pubescence removal experiments on Puya hamata, a páramo species, demonstrated that pubescence is an effective insulator, maintaining elevated flower temperatures. In Puya clava-herculis (also a páramo species) elevated flower temperatures were associated with higher seed set. Thus, the greater production of inflorescence pubescence in páramo species of Puya may be an important factor contributing to reproductive success in these higher elevation species.     

Growth and mercury accumulation in yearling yellow perch,Perca flavescens,in the Ottawa River,Ontario

Synopsis Diet, growth, energy content and mercury concentrations of yearling yellow perch,Perca favescens, were determined from June 1974 through May 1975. Benthic invertebrates predominated in the diet throughout the summer with zooplankton important in June and fish in August and September. Ash, lipid, protein and energy content of the yearling yellow perch increased through the summer reaching maximal values in August, 1974. Fish collected May 15, 1975 has reduced ash, lipid., protein and energy content with an increased moisture content. Both protein and lipid were catabolized during overwintering. Seasonal variation in organic mercury concentration was not significant (p>0.05). Inorganic mercury decreased significantly (p0.05) in September, 1974 and May, 1975 samples, reflecting changes in diet and the shorter biological half-life of inorganic mercury. The pollutant bioaccumulation model of Norstrom et al. (1976) adequately described the observed accumulation of organic mercury in young perch from June through September 1974, but either underestimated uptake or overestimated clearance for the period October 1974–May 1975.