Biomass and Energy of Casuarina equisetiofolia Plantations in Southeast Coast of China

1 INTRODUCTIONMore than 85% of living energy depends on fuel woodin developing countries. In Asia, except Japan, fuelwood consumed was over 2/3 of the total wood.China is a developing country lacking of energy,especially in the countryside. Bioenergy was a mainkind of energy sources, and dominated the importantstatus, occupying 3/4 of the energy needed in dailylives, and about half of the total energyconsumption ( Li Huiqing, et al, 1999). Averagely ina year each farmer needs 657 kg fue…     

Distribution patterns of vegetation biomass and nutrients bio-cycle in alpine tundra ecosystem on Changbai Mountains, Northeast China

A study was conducted to test the correlation between biomass and elevation and the differences in concentration and storks of nutrients among five vegetation types （Felsenmeer alpine tundra vegetation-FA, Lithic alpine tundra vegetation-LA, Typical alpine tundra vegetation-TA, Meadow alpine tundra vegetation-MA, and Swamp alpine tundra vegetation-SA） on alpine tundra of Changbai Mountains, Jilin Province, China in growing seasons of 2003, 2004 and 2005. The biomass of 43 mono-species and soil nutrients in alpine tundra ecosystem were also investigated. Dominant species from Ericaceae （such as Rhododendron chrysanthum and Vaccinium jliginosum var. alpinum） were taken to analyze organ biomass distribution. Result showed that the biomass and elevation had a significant correlation （Biomass-237.3 in（Elevation） ＋494.36; R^2=0.8092; P〈0.05）. No significant differences were found in phosphorus and sulphur concentrations of roots, stems and leaves among the five vegetation types. There were significant differences in nitrogen and phosphorus stocks of roots, stems and leaves and in sulphur stock of stems and leaves among TA, MA, and SA vegetation types （p〈0.05）. The nutrient stock of five vegetations was averagely 72.46 kg.hm^-2, of which N, P, S were 48.55, 10.33 and 13.61 kg·hm^-2, respectively. Soil N and S concentrations in meadow alpine tundra soil type was significantly higher than those in other four soil types （Cold desert alpine tundra soil, Lithic alpine tundra soil, Peat alpine tundra soil, and Gray alpine tundra soil）. Phosphorous concentration in SA type was higher （p〈0.05） than in other types. Soil nutrient stock （0-20cm） was averagely 39.59 t.hm^-2, of which N, P, S were 23.74, 5.86, 9.99 t·hm^-2, respectively.     

Effect of livestock grazing and human uses on herbaceous species diversity in oriental beech （Fagus orientalis Lipsky） forests,Guilan, Masal,northern Iran

Plant diversity plays key ecological roles in forest ecosystems, including influencing succession, resilience and nutrient cycling. This study was conducted to investigate the effect of livestock grazing and human uses on herbaceous species diversity. We surveyed 50 ha of protected area and 50 ha of unprotected area to evaluate herbaceous species diversity in oriental beech （Fagus orientalis Lipsky） forests in northern Iran. We calculated and compared three indices each of diversity and evenness, and species richness between the two areas. Herbaceous cover was higher in the unprotected area while leaf litter depth and tree canopy cover were higher in the protected area. The diversity indices, H （Shan- non-Wiener index ）, N~ （McArthur index）, N2 （Hill＇s index）, EQ （Modified Nee index）, E,ar （Smith-Wilson index）, E5 （modified index of Hill） and R=S （species richness） and species richness R=S were greater in the protected area than in the unprotected area, suggesting that protection from grazing results in increased numbers of plants and species. The effect of land protection on plant diversity was more pronounced for evenness than for species richness and the positive correlation between diversity and evenness indices was higher than that between diversity and richness.     

Effects of nitrogen content on growth and hydraulic characteristics of peach （Prunus persica L.） seedlings under different soil moisture condi- tions

A pot experiment was conducted to investigate the effects of nitrogen content [N1(no fertilizer), N2(0.15 g?kg–1), and N3(0.3 g?kg–1)] on the growth and the hydraulic characteristics of peach seedlings under different soil moisture conditions(W1, W2 and W3, in which the soil water content was 45% to 55%, 60% to 70%, and 75% to 80% of the field water capacity, respectively) by using a specialized high pressure flow meter with a root chamber and a coupling, which was connected to plant organs. Leaf area and leaf hydraulic conductivity(KL) increased significantly in the seedlings because of increased soil moisture and N content. KL increased with leaf area. A linear correlation was documented between KL and leaf area. KL was higher in the morning and began to decline sharply after 16:00, at which KL declined after an initial increase. Soil moisture and N content enhanced shoot(Ks) and root(Kr) hydraulic conductivities, thereby improving the low soil moisture condition to a large extent. Ks and Kr of the seedlings were reduced by 32% and 27% respectively in N1, and by 14.7% and 9.4%, respectively in N2, and both in W1, compared with the control treatment. N3 had no significant effect on Ks and Kr under similar conditions. Linear negative correlations were observed between Kr and the excised root diameter as well as between Ks and the shoot stem diameter. The shoot-to-root ratio increased with increase in N content. The shoot-to-root ratio in N3 was increased by 14.37%, compared with N1 in W1 as well as by 12% and 4.39% in W2 and W3, respectively. Knowledge of the effects of soil moisture and N fertilizer on hydraulic characteristics and growth is important. Our results provide basic guidelines for the implementation of water-saving irrigation and fertilization management of nursery stock.     

氮肥对盆栽欧洲水青冈生物量和营养分配的影响(英文)

调查了施加氮肥(15NH4和15NO3)处理后在两个连续生长季内欧洲水青冈(Fagus sylvatica L.)幼苗地上部分和地下部分的生物量和营养元素分配。盆栽欧洲水青冈幼苗培养于温室大棚内,培养土样取自相邻的三种林分:欧洲水青冈,挪威赤松,欧洲水青冈-赤松混交林。结果表明,氮肥(15N)处理对欧洲水青冈营养元素分配没有显著影响,施加氮素形式决定自身流入植物库的情况。欧洲水青獭收氮素主要以硝态氮的形式,因此,尽管植物体内保存的硝态氮和氨态氮并没有统计差异,但是叶片中硝态氮明显减少。施加硝态氮对欧洲水青冈氮素恢复的影响要大于施加氨态氮。与欧洲水青冈茎、粗根相比,优质根系对氮素(15N)固定是一个缓慢过程。表8图1参40。     

15N标记氮在盆栽山毛榉中的分配

温室条件下,向盆栽山毛榉幼苗中施加192g.m·^-2^15N示踪物,研究连续两个生长季沉积氮在森林土壤（含森林地被物）、沥出物、以及地上和地下部分生物量的分配。模拟了四种处理（栽培和非栽培）下的NH4^＋和NO3^-沉积情况,每种处理各自标记为^15N-NH4^＋或者^15N-NO3^-。在整个体系中施加15N的总回收率分别是,盆栽处理的^15N-NH4^＋为67.3%～74.9%,非盆栽处理的^15N-NO3^-为85.3%～88.1%。两种^15N示踪物主要沉积在森林土壤（包括森林地被物）中,其中盆栽处理的森里土壤中^15N-NH4^＋为34.6%～33.7%,^15N-NO3^-为13.1%～9.0%,说明异养微生物有很强的固氮作用。森林土壤微生物对^15N-NH4^＋的固定能力比^15N-NO3^-的固定能力强三倍。^15N-NH4^＋的优先异养利用造成土壤中^15N-NH4^＋的沉积量是植物体保存量的两倍 而土壤中^15N-NO3^-的沉积量却低于植物体的。总之,植被-土壤系统中15N-NH4＋的沉积量比^15N-NO3^-的沉积高了60%,说明了沉积氮的形式在森林生态系统中氮保存中的重要性。     

Effect of canopy gap size and ecological factors on species diversity and beech seedlings in managed beech stands in Hyrcanian forests

We studied the species diversity of the herb layer and ecological factors in harvest-created gaps in beech stands under a single-tree selection system in Northern Iran. To determine diversity, the number of beech seedlings, and other ecological factors, 16 gaps were selected and subplots of 5 m2 were positioned at the centre and at the cardinal points of each gap. Species richness and Simpson diversity index increased with increasing gap area as did numbers of seedlings. With increasing humus layer thickness, species richness declined but the Hill evenness index increased. Species richness increased with increasing light availability. There was no relationship between crown radii of beech trees and diversity indices. Correlations between environmental factors and numbers ofindividuals of some species in the herb layer were not significant except in a few cases. The results help explain the effects of man-made gaps on the dynamics of managed beech stands and this benefits evaluation of silvicultural operating plans.     

Growth and biomass production in Azadirachta indica seedlings in response to nutrients (N and P) and moisture stress

Production of quality seedlings is an important aspect of successful tree planting. No information is available on the effect of nutrients and water on the growth and development of the seedlings of neem (Azadirachta indica A. Juss), an important component of many tropical agroforestry systems. In an experiment in central India, the growth and nutrient-use efficiency of neem seedlings grown at various levels of light, nutrients (N and P), and water stress were determined. Seedlings were given light (diffused and complete) and nutrient (N and P) treatments comprising either high N-high P, high N-low P, low N-high P, or low N-low P. Seedlings grown in complete light (800 mol/m²/s) had four times more biomass than those grown in diffused light (200 mol/m²/s). Significant increase in seedling biomass was observed with nitrogen application, while phosphorus had no effect on biomass. Leaves contributed maximum biomass, followed by roots and stem. Nutrient use efficiency decreased with an increase in the supply of nutrients. In another experiment, containerized and bare-root seedlings were subjected to five watering treatments, viz., watering twice a week, watering weekly, watering every alternate week, watering every third week, and natural precipitation. Plant moisture stress affected both growth and survival of neem seedlings. Only 50 per cent of seedlings survived in severe drought treatment (no. 4) whereas 90 to 95 per cent seedlings showed growth in all other treatments. Plant moisture stress in severe drought treatment averaged –21 bar while in other treatments it ranged from –9 to –12 bar. Shoot-root ratio was high in bare-root seedlings as compared to containerized seedlings. Containerized seedlings had shown better endurance against drought than the bare-root seedlings. The results suggest that neem seedlings adjust their nutrient use efficiency and can be grown even under limited available resources. It is also inferred that the species can tolerate soil resource depletion caused by competitor species.This revised version was published online in November 2005 with corrections to the Cover Date.     

氮肥对黄檗一年生苗木生长的影响

采用叶面施肥的方法,对黄檗1 a生苗木进行追施氮肥试验,结果表明:施氮肥可显著促进苗木生长,其中以20 g.m-2施肥量效果最为理想,平均苗高38.6 cm,平均地径1.05 cm,平均主根长16.7 cm,平均侧根数29.7个,平均鲜重103.9 g,平均干重30.78 g,分别是对照的111%、144%、132%、182%、149%和148%;20 g.m-2是黄檗1 a生苗木的适宜氮肥追施量。     

油茶轻基质容器苗木缓控专用肥研究

为了了解缓控肥对油茶轻基质容器苗生长的影响情况,以研发促进容器苗生长的缓控专用肥,以优良无性系长林4#为试验材料,采用单因素完全随机试验设计,设置如下7个缓控肥配方——(1)14︰14︰14+TE+B.3~6M、(2)15︰25︰20+TE+B.3~6M、(3)18︰18︰10+TE+B.4~6M、(4)20︰8︰10+TE+B.3~6M、(5)20︰10︰15+TE+B.4~6M、(6)17︰11︰12+TE+B.3~6M、(7)25︰5︰6+TE+B.3~6M,每个供试肥料配方处理下又各设置了0.2、0.3、0.4、0.5 g/株4个施肥量处理,就不同缓控肥配方及其不同施用量处理对1年生油茶轻基质容器苗生长状况的影响情况进行了试验、观测与分析。结果表明:7个供试肥料配方均能促进苗木地径、苗高的生长及苗木叶片数量的增加,其中配方(3)的效果最优,配方(2)和配方(7)的效果均较优;各配方的最佳施肥量为0.4~0.5 g/株,即基质量为2.5~3.0 kg/m3。     

Effects of solid water and foliar fertilizer on survival and growth of seedlings in sand prevention and control

To promote afforestation in sandy lands and increase the effects of prevention and control of desertification, the application of a new drought-resistant product—solid water and foliar fertilizer “Shifengle”—was studied. A comparison of three treatments (solid water, foliar fertilizer, and control) showed that both solid water and foliar fertilizer increased plant survival rate by 10% and 18.2%, respectively. Afforestation survival rates of Salix psammophila and Hedysarum mongolicum reached over 90%. In addition, height and crown growth as well as biomass of seedlings were improved by the treatments. __________ Translated from Journal of Beijing Forestry University, 2006, 28(3): 76–80 [译自: 北京林业大学学报]     

Biomass and nutrient allocation in Douglas-fir and amabilis fir seedlings: influence of growth rate and temperature

Allocation of biomass and nutrients to current-year and one-year-old shoots and roots of two-year-old conifer seedlings with differing rates of growth was studied. Differences in growth rate were achieved by selecting fast- and slow-growing populations of the relatively fast- and slow-growing conifer species, Pseudotsuga menziesii (Mirb.) Franco and Abies amabilis Dougl. ex Loud, respectively. Environmentally controlled differences in growth rate were induced by placing half of the seedlings in a 10 degrees C growth chamber and half in a 20 degrees C growth chamber in their second growing season. Seedling samples were harvested in May, before the temperature treatment, and in July and November of the second growing season, and biomass and nutrient concentrations of current-year and one-year-old shoots and roots were determined. Seedling biomass and nutrient allocation differed among the high-growth treatments. Seedlings exhibiting high growth in response to the 20 degrees C treatment and faster growing populations within species both showed increased allocation to new shoots, whereas seedlings of the fast-growing species showed greater allocation to old shoots than to new shoots. Increased growth increased nutrient uptake, but nutrient concentration decreased with growth rate as a result of dilution, so that faster-growing seedlings had greater nutrient-use efficiency than slower-growing seedlings. Retranslocation of P and K was seen in the second year only in slow-growing populations at 10 degrees C. Nutrient concentrations of one-year-old plant parts decreased in the second year, indicating new growth was a stronger sink for nutrients than second-year growth.     

Biomass and nutrient allocation in Douglas-fir and amabilis fir seedlings: influence of growth rate and nutrition

Allocation of biomass and nutrients to shoots and roots was followed for three years in fast and slow growing populations of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a fast growing pioneer species, and amabilis fir (Abies amabilis Dougl. ex J. Forbes), a slow growing shade-tolerant species. Seedlings were grown for three seasons in five nutrient treatments containing varying proportions of nitrogen and phosphorus (N:P). In both species, growth was greatest in the 250:20 N:P treatment followed by the 100:60 and 100:20 treatments. Vector analysis showed that, in both species, relative to the 100:20 treatment, seedlings in the 20:20 treatment were N deficient and seedlings in the 100:4 treatment were P deficient, i.e., where deficiency is defined to mean that an increase in nutrient supply increases nutrient content, nutrient concentration and plant dry weight. Seedlings in the 100:60 treatment had a higher P content than seedlings in the 100:20 treatment but the same dry weight, indicative of what Timmer and Armstrong (1987) termed luxury consumption. No nutrient retranslocation was observed in either species until the third growing season. In Douglas-fir, the greatest percentage of nutrients was exported from one-year-old shoots between May and July of the third growing season to support new growth. The total amount and percent of nutrients retranslocated was higher in Douglas-fir than in amabilis fir. Amabilis fir seedlings also exported N and P from older shoots, but this was later partially replenished. In both species, P retranslocation was greatest in treatments with a high N:P ratio. Nitrogen retranslocation was greatest in amabilis fir seedlings in treatments with a low N:P ratio, and greatest in Douglas-fir seedlings in the 250:20 and 100:60 treatments. Potassium retranslocation was correlated with seedling size. Douglas-fir retranslocated more of its shoot N reserves into new growth at the expense of older needles when soil fertility was high and sinks were strong. Otherwise, both species preferentially translocated the elements in short supply. Thus, retranslocation varied with the ecological characteristics of species, the relative availability of soil nutrients and sink strength.     

控释肥对薄壳山核桃容器苗营养生长的影响

研究了2种控释肥(APEX 19-6-12和APEX 14-14-14)在低、中、高(2、6、10 g/L)质量浓度下对薄壳山核桃容器苗营养生长的影响。结果表明:控释肥对苗木生长具有促进作用,但因肥料配方和施用质量浓度不同而异;10 g/L APEX 14-14-14和6 g/L APEX 19-6-12的处理下,苗木品质指数最高,分别为0.26和0.30;除10 g/L APEX 19-6-12处理外,所有的控释肥处理均显著促进了苗木生长停滞期的营养生长,茎体积日增量在7月中旬和8月下旬达到两个高峰,分别是32.6 mm3/d(6 g/L APEX 14-14-14)和20.7 mm3/d(6 g/L APEX19-6-12);N、Ca含量均与肥料配方和施肥质量浓度相关,相同质量浓度下APEX19-6-12处理的苗木营养元素含量高于APEX 14-14-14处理;K含量仅受控释肥配方影响,Mg含量则既不受配方影响也不受施用质量浓度的影响;除了K外,其它3种元素在植株各器官中的分配均不受控释肥配方的影响。