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1.
Nutrient Dynamics in Himalayan Alder Plantations 总被引:4,自引:1,他引:3
Dynamics of four macro-nutrients were studied in an age series(7, 17, 30, 46 and 56 years) of Himalayan alder (Alnus nepalensisD. Don) plantations in the Kalimpong forest division of theeastern Himalayas. Concentrations of nutrients were in the orderN > K > Ca > P in most of the tree components and inunderstorey vegetation. There was an inverse relationship betweennutrient concentrations of perennial parts and diameter at breastheight. The relative contributions of standing state of nutrientsin different tree components of mature plantations were in theorder; bole > branch > below-ground part > twig andleaf > catkin. Sequential arrangement of nutrient storagein tree components was: N > K > Ca > P. Soil totalN and available P increased with plantation age. Annual inputsof nutrients (kg ha-1) to the forest-floor via litterfall were:183-235 N, 4·9-7·0 P, 33·5-39·5K, and 9·2-10·8 Ca. Total annual accretion ofN through biological fixation ranged from 29 to 117 kg ha-1in different plantations. Turnover rate and turnover time fordifferent nutrients in the age series of plantations fluctuatedbetween 0·10-0·55 year-1 and 1·8-9·3years, respectively. Nutrient use efficiencies decreased withplantation age for all nutrients except for calcium. Uptakeof nutrients is a more energy consuming process than release.Copyright1993, 1999 Academic Press Alnus nepalensis D. Don, plantation age, nitrogen accretion, nutrient concentration, standing state, uptake, turnover 相似文献
2.
Structure and Function of an Age Series of Eucalypt Plantations in Central Himalaya. I. Dry Matter Dynamics 总被引:2,自引:1,他引:1
The biomass and net primary productivity (NPP) of 2- to 8-year-oldplantations of Eucalyptus tereticornis Sm. (= E. hybrid) growingin the tarai (a level area of superabundant water) region ofCentral Himalaya were estimated. Allometric equations for allthe above-ground and below-ground components of trees and shrubswere developed for each stand. Understorey, forest floor biomassand litter fall were also estimated from stands. Shrubs appearedfirst at 5-year-old plantation. The biomass of vegetation, forestfloor littermass, tree litter fall and net primary productivity(NPP) of trees and shrubs increased with the increase in plantationage, whereas herb biomass and NPP significantly (P < 0·01)decreased with the increase in plantation age. The total plantationbiomass increased from 7·7 t ha1 in the 2-year-oldto 126·7 t ha1 in the 8-year-old plantation andNPP from 8·6 t ha1 year1 in the 2-year-oldto 23·4 t ha1 year1 in the 8-year-old plantation.The biomass accumulation ratio ranged from 0·81 to 5·93. Eucalyptus tereticornis Sm, plantation, biomass, forest floor, litter fall, net primary productivity, biomass accumulation ratio 相似文献
3.
Biomass and phosphorus distribution and accumulation rates wereestimated for an undisturbed subtropical rainforest in northernNew South Wales. The accumulation rates were estimated overa 16-year period. It is estimated that the steady-state above-groundbiomass for this forest is 35.0 tonne ha1. Most of theannual biomass production was replacing litterfall and mortality.The above-ground forest contained 52 kg P ha1 with agross annual accumulation of about 0.4 kg P ha1/yr1.The forest understorey and forest floor contained 4.7 kg P ha1and 7.9 kg P ha1, respectively. The annual uptake wasapprox. 4 kg P ha1 yr1. The phosphorus utilizationof this stand was compared with that of a Eucalyptus grandisplantation Sub-tropical rainforest, biomass accumulation, phosphorus cycling 相似文献
4.
Species Structure, Dry Matter Dynamics and Carbon Flux of a Dry Tropical Forest in India 总被引:4,自引:0,他引:4
Species composition, plant biomass and net primary productivitywere studied on three sites of a dry tropical forest The forestwas characterized by small structure with 3810.4 m2 ha1tree and 3 17 8 m2 ha1 shrub basal cover Speciesdiversity was highest for the mid-slope site while the concentrationof dominance was greatest for the hill-top stand The beta diversitywas 3 1 Total standing crop of vegetation averaged 66 98 t ha1with 46 70 t ha1 in the tree layer, 13.97 t ha1in the shrub layer, 0.35 t ha1 in the herb layer, 2 83t ha1 in the litter layer and 3 13 t ha1 in fineroots Of the total annual litterfall (4 886.71 t ha1),69% was accounted for by leaves and 31% by non-leaf matter Netprimary production (NPP) ranged between 11 3 and 19 2 t ha1year1, to which the contributions of trees, shrubs andherbs averaged 72, 22 and 6%, respectively Contribution of rootsto NPP was substantial and ranged from 2 9 to 5 3 t ha1year1 A total of 83% of vegetation carbon was storedin the above-ground plant parts while the above-ground NPP wasresponsible for 72% of the total carbon input into the systemThe contribution of foliage, herbaceous vegetation and fineroots to carbon turnover was disproportionately larger comparedto their share in the total standing crop Carbon budgeting indicatedthat the forest was an accumulating system, over at least theshort term Dry tropical forest, biomass, litterfall, net primary production, carbon budget, carbon flux 相似文献
5.
The Structure and Function of Pine Forest in Central Himalaya. I. Dry Matter Dynamics 总被引:2,自引:0,他引:2
The present study deals with structure and function of fourareas of Himalayan chir pine forest. Tree layer was monospecificon all sites with varied density and basal cover in the rangeof 5401630 individuals per ha and 25·047·2m2ha1, respectively. Shrubs having low density were sparselydistributed. All allometric equations relating to biomass ofdifferent components, to circumference at breast height (cbh)were significant, with the exception of that for cone biomass.Total vegetation biomass (115236 t ha1) was distributedas 113283 t ha1 in trees. 0·560·82t ha1 in shrubs and 1·632·57 t ha1in herbs. Total forest floor biomass including herbaceous litterranged between 9·6 and 13·6 t ha1. Of thetotal annual litter fall (4·267·38 t ha1),60·375·1 per cent was distributed in leaflitter and 24·939·7 per cent in wood litter.Turnover rate of tree litter varied from 0·45 to 0·53,whereas rates for shrubs and herbs were assumed to 1. Net primaryproduction of total vegetation ranged between 9·91 and21·2 t ha1 year1, of which the contributionof trees, shrubs and herbs was 76·5 88·1per cent 0·61·8 per cent and 11·321·5per cent, respectively. A compartment model of dry matter onthe basis of mean data across sites was developed to show drymatter storage and flow of dry matter within the ecosystem. Pinus roxburghii forest, biomass, litter fall, net primary production, compartmental transfer 相似文献
6.
The present study deals with structure and functioning of threeareas of Himalayan oak forest. Low- and mid-altitude oaks, namelyQuercus leucotrichophora, and Quercus floribunda, form predominantevergreen forests in Central and Western Himalaya. The totaltree basal cover ranged between 33·89 m2 ha1 (Q.floribunda site) to 36·83 m2 ha1 (Q. leucotrichophorasite). The density ranged between 570 and 760 individuals ha1.Allometric equations relating biomass of different tree componentsto GBH (girth at breast height) were significant with the exceptionof leaf biomass in Q. leucotrichophora and Rhododendron arboreum.Total vegetation biomass (29·40467·0 tha1) was distributed as 377·1 t ha1 intrees, 5·40 t ha1 in shrubs and 1·23 tha1 in herbs. Total forest floor biomass ranged between4·6 and 6·2 t ha1. Of the total annuallitter fall (4·74·8 t ha1), 77·5% was contributed by leaf litter, 17·8 % by wood litterand 4·7 % by miscellaneous litter. Turnover rate of treelitter varied from 0·66 to 0·70. Net primary productionof total vegetation ranged between 15·9 and 20·6t ha1 yr1, of which the contribution of trees,shrubs and herbs was 81·2 %, 8·6 % and 10·2%, respectively. A compartment model of dry matter on the basisof mean data across sites was developed to show dry matter storageand flow of dry matter within the system. Quercus leucotrichophora forest, Q. floribunda forest, Q. lanuginosa forest, biomass, litter fall, net primary production, compartmental transfer 相似文献
7.
The productivity of a stand of Salix glauca at 68° N inArctic Norway was investigated. The biomass was 18.4 t ha1and the annual production was 1.341.56 t ha1 year1.These low values are attributed to the short growing season.The mean age of the stems was 23.4 years. The prostrate-ascendinggrowth form of the plants is regarded as an adaptation to thesevere winter climate. 相似文献
8.
Structure and Function of an Age Series of Poplar Plantations in Central Himalaya: I Dry Matter Dynamics 总被引:2,自引:2,他引:0
The biomass and net primary productivity (NPP) of 5- to 8-year-oldpoplar (Populus deltoides Marsh, Clone D121) plantations growingin the Tarai belt (low-lying plains with high water table adjacentto foothills of central Himalaya) were estimated. Allometricequations for all the above-ground and below-ground componentsof trees and shrubs were developed for each stand. Understorey,forest floor biomass, and litter fall were also estimated fromstands. The biomass of plantation, forest floor litter mass,tree litter fall and net primary productivity (NPP) of treesand shrubs increased with increase in plantation age, whereasherb biomass and NPP significantly (P < 0·01) decreasedwith increasing plantation age. The total plantation biomassincreased from 84·0 in the 5-year-old to 170·0t ha-1 in the 8-year-old plantation and NPP from 16·8t ha-1 year-1 in the 5- and 6-year-old to 21·8 t ha-1year-1 in the 8-year-old plantation. The biomass accumulationratio (biomass: net production, BAR) for different tree componentsincreased with the age of plantation increase. The BAR ratioranged from 4·9 in the 5-year-old to 7·7 in the8-year-old plantation.Copyright 1995, 1999 Academic Press Populus deltoides plantations (Clone D121), biomass, dry matter turnover, net primary productivity, Tarai belt of Central Himalaya 相似文献
9.
The cycling of nitrogen, phosphorus, calcium, magnesium andpotassium in a series of western Washington Douglas-fir [Pseudotsugamenziesii (Mirb.) Franco] stands ranging in age from 9 to 95years has been described. The stands were of relatively lowproductivity being limited by low nitrogen. The content of nitrogen,phosphorus, magnesium and potassium in tree foliage all tendedto stabilize at about 40 years whereas calcium continued toincrease. The content of all nutrients in the wood continuedto increase with stand age. Nitrogen in the forest floor accumulatedconstantly at about 5.7 kg ha1 year1 and thistogether with the above-ground tree accumulation meant about10.5 kg ha1 year1 nitrogen was immobilized. Calciumalso increased with time in the forest floor with age whereasthe other nutrients were fairly constant after about 30 years.Understorey nutrient content reached a peak at about 20 years,while understorey litter-fall was significant throughout theage sequence. Internal redistribution, especially of nitrogen,represented an increasingly greater proportion of stand requirementwith increasing stand maturity. Pseudotsuga menziesti (Mirb.) Franco, Douglas-fir, biomass, litter-fall, nutrient content, nutrient cycling 相似文献
10.
Nitrogen Economy of Post-fire Stands of Shrub Legumes in Jarrah (Eucalyptus marginata Donn ex Sm.) Forest of S.W. Australia 总被引:1,自引:0,他引:1
HANSEN ALEXANDER P.; PATE JOHN S.; HANSEN ANNETTE; BELL DAVID T. 《Journal of experimental botany》1987,38(1):26-41
Hansen, A. P., Pate, J. S., Hansen, A. and Bell, D. T. 1987.Nitrogen economy of post-fire stands of shrub legumes in jarrah(Eucalyptus marginata Donn ex Sm.) forest of S.W. Australia.J.exp. Bot. 38: 2641. Growth, demography and N economy of 16-year-old standsof Acacia pulchella, A. alata, A. extensa and Bossiaea aquifoliumwere examined using population sampling to assess annual incrementsof N as living biomass, and returns of N as litter, seed anddead plants. Dependence on nitrogen fixation was assessed fromseasonal profiles of acetylene reduction, employing data fromprevious calibrations to convert C2H2 reduced to N2 fixed. After2 years of slow growth and minimal reproduction all speciesgrew rapidly to achieve maximum or near maximum size and seedproduction. Intense self-thinning of stands occurred in thesecond and third years, especially in the highly dense standsof the smallest species, A. alata. Annual turnover in standsranged from 0?3 to 127 kg N ha1 year1, dependingon species current age and density of a stand. Returns of Nas litter and shed seed comprised small proportions of the annualbudgets, but returns due to plant death equalled or exceededincrements of living biomass in years when stands were thinningrapidly. Proportional dependencies of the species on fixed N2were relatively high (1361%) in first year seedlings,and then declined markedly to 1?13?4percnt; in the second,0?31?6% in the third, and, with one exception, to wellbelow 1% in the fourth and sixth year stands. Mean annual ratesof N2 fixation over the 6-year post-fire period were 1?6 kgN ha1 year1 for A. alata, 049 for A. pulchella,0?19 for B. aquifolium and 0-10 for A. extensa Key words: Shrub legumes, post-fire N economy 相似文献
11.
Fine root production and mortality in central Himalayan evergreenforests consisting of Quercus leucotrichophora (banj oak) andPinus roxburghii (chir pine) were measured. Fine root productionand mortality decreased with increasing soil depth. Annual fineroot production was higher in the broadleafed forest than inthe coniferous forest, across months and seasons (1.3 and 1.5-timesmore living and dead root biomass, respectively in banj oakthan in chir pine). Live fine root production was 2508 kg ha-1year-1inchir pine forest and 3631 kg ha-1year-1in banj oak forest. Deadfine roots accumulated at a rate of 1197 and 1525 kg ha-1year-1inchir pine and in banj oak forest, respectively. In both forests,the greatest fine root production was recorded in the rainyseason followed by summer and winter seasons. Both soil androot nitrogen concentration decreased with increasing soil depth.Nitrogen uptake was higher in banj oak forest (12.1 kg ha-1year-1)than chir pine forest (7.2 kg ha-1year-1).Copyright 1999 Annalsof Botany Company Fine root production, fine roots, necromass, banj oak, chir pine, Quercus leucotrichophora , Pinus roxburghii . 相似文献
12.
Nutrient Movement in Litter Fall and Precipitation Components for Central Himalayan Forests 总被引:1,自引:0,他引:1
The annual total litter fall in six Central Himalayan forestsranged from 2.1 to 3.8 t C ha1, of which 54 to 82 percent was leaf litter, 920 per cent wood litter and 614per cent other litter. In all forests the order of relativeabundance of nutrients (kg ha-1 year-1) in litter fall was Ca(50.891.6) > N (47.772.2) > K (22.837.1)> P (4.16.4). Leaf litter accounted for 6395per cent of the total nutrients returned through litter fall. In these forests throughfall ranged from 71.3 to 81.4 per cent,stemflow from 0.50 to 2.16 per cent and canopy interceptionfrom 17.7 to 28.2 per cent of the gross rainfall. In the incidentrainfall the concentration and annual input of Ca was the greatestand of P the least. Canopy precipitation was richer in all nutrientscompared to incident rainfall. Net gain of nutrients from thecanopy ranged from 0.16 kg ha-1 year-1, for P, to 17.77 kg ha-1year-1 for K. Leaching was greatest for K and least for N. Ofthe total quantity of nutrients returned to the soil, 11 to46 per cent was accounted for by precipitation components. Thusprecipitation inputs play a significant role in nutrient cyclingof these forests. Himalaya, forest, litter fall, precipitation components, nutrients 相似文献
13.
The Kinetics of Tracheid Development in Tsuga canadensis Carr. and its Relation to Tree Vigour 总被引:1,自引:0,他引:1
Cell counts from samples taken at weekly intervals, from 14May to 22 October 1969, in a T. canadensis stand in Massachusetts,U.S.A., showed that the width of the annual ring was correlatedwith the rate of cell production and that only the least vigoroustrees (c. 20 tracheids year1) had a shorter growing season.The time required for completion of a cell-division cycle inthe cambial zone decreased during the course of the season,from 35 to 20 days for the less vigorous trees (2545tracheids year1) and from 28 to 10 days for the morevigorous trees (45100 tracheids year1). The timerequired for the completion of radial growth of the tracheidsdecreased from 18 to 9 days, with no evidence of any changeswith tree vigour. The actual radial growth-rate of the tracheidswas constant within the range 1.53 um day1. Thetime required for deposition of the secondary cell wall increasedfrom 10 to 50 days, with little evidence of any changes withtree vigour. The actual rate of deposition of cell wall materialwas about 0.15 µ2 µ1 day1 and seemedto show little change during the course of the season. The timeperiod required for lysis of the cytoplasm was about 4 days,with no evidence of any changes with tree vigour and littleevidence of any changes during the course of the season. 相似文献
14.
Structure and Function of High Altitude Forests of Central Himalaya I. Dry Matter Dynamics 总被引:2,自引:0,他引:2
The present study deals with the structure and functioning ofthree different forest communities, viz., horse chestnut, silverfir and kharsu oak forests, in a high altitude region of CentralHimalaya. The tree density and total basal cover of horse chestnutforest was 280 and 76, silver fir forest 355 and 106, and kharsuoak forest 480 trees ha-1 and 73 m2 ha-1, respectively. Allometricequations relating biomass of different tree components to cbh(circumference at breast height) were significant. Total vegetationbiomass was 505 t ha-1 in horse chestnut, 566 t ha-1 in silverfir and 593 t ha-1 in kharsu oak forests, of which maximum contributionwas by tree layer followed by shrub, herb, sapling and seedlinglayers. The forest floor litter biomass was 2·1, 4·7and 4·2 t ha-1 in horse chestnut, silver fir and kharsuoak forests, respectively. The total litter fall was 7·3,6·7 and 9·4 t ha-1 year-1, of which leaf littercontributed 48, 39 and 64% in horse chestnut, silver fir andkharsu oak forests, respectively. Turnover rate of tree litterwas 0·80 in horse chestnut, 0·61 in silver firand 0·71 in kharsu oak forests. Net primary productionof total vegetation was 19·6, 18·9 and 24·9t ha-1 year-1, of which tree layer contributed maximum proportionfollowed by herb, shrub, sapling and seedling layers. To showdry matter storage and flow of dry matter within the system,compartment models were developed for all forests.Copyright1995, 1999 Academic Press Total basal cover, biomass, productivity, Quercus, Aesculus, Abies, high altitude, litter, compartmental transfer 相似文献
15.
The mechanism of SO2-induced changes in stomatal conductance(g) of alder was examined to determine if SO2 affects guardcell function directly or indirectly through the SO2-inducedchanges in photosynthesis. During experimental fumigations at SO2 concentrations of 33µmol m3 (0.08 µl l1), stomatal closurepreceded declines in net photosynthetic rate (A), indicatingthat SO2 can directly affect guard cells. From these and otherstudies it appears that the sequence of A and g responses maybe influenced by SO2 concentration as well as by species. Fumigation with SO2 did not cause increases in g, even whenthe intercellular substomatal CO2 concentration (ci) was reducedby 50 µmol mol1. Increases in g are not attributableto SO2 effects on the CO2-based stomatal control system. Key words: Air pollution, Alnus serrulata, gas exchange, stomata, sulphur dioxide 相似文献
16.
17.
Biomass and net production were measured in aPhyllostachys bambusoides stand in Kyoto Prefecture, central Japan, which had carried out gregarious flowering in 1969 and has been recovering vegetatively.
The culm density fluctuated around an average value of 12 040 ha−1 during the research period (1985–91). Annual recruirment and mortality rates of culms were 1340 and 1133 ha−1, respectively. The mean diameter at breast height increased from 7.28 cm in 1985 to 8.68 cm in 1991, and the biomass of culms
increased from 71.3 to 111.6t ha−1 over the same time period. Branch and leaf biomasses were almost constant, 10.0 and 9.4t ha−1 on average, respectively. The leaf area index of the stand was 11.6 ha ha−1, which is one of the largest values found in Japanese forests. The belowground biomass of 32.6t ha−1 for rhizomes and 14.8t ha−1 for fine roots resulted in the smaller ratio of aboveground parts to the root system (2.38) than those determined for forest
stands. The amount of litterfall, excluding culms and large branches, was large (9.13t ha−1 year−1), corresponding to those measured in equatorial stands. The aboveground net production was 24.6t ha−1 year−1, larger than the average value reported for forest stands under similar weather conditions. 相似文献
18.
An estimate of global primary production in the ocean from satellite radiometer data 总被引:32,自引:0,他引:32
Longhurst Alan; Sathyendranath Shubha; Platt Trevor; Caverhill Carla 《Journal of plankton research》1995,17(6):1245-1271
An estimate of global net primary production in the ocean hasbeen computed from the monthly mean near-surface chlorophyllfields for 19791986 obtained by the Nimbus 7 CZCS radiometer.Our model required information about the subsurface distributionof chlorophyll, the parameters of the photosynthesis-light relationship,the sun angle and cloudiness. The computations were partitionedamong 57 biogeochemical provinces that were specified from regionaloceanography and by examination of the chlorophyll fields. Makingdifferent assumptions about the overestimation of chlorophyllby the CZCS in turbid coastal areas, the global net primaryproduction from phytoplankton is given as 4550 Gt C year1.This may be compared with current published estimates for landplants of 4568 Gt C year1 and for coastal vegetationof 1.9 Gt C year1. 相似文献
19.
Hiroyuki Tobita Shigeaki F Hasegawa Kenichi Yazaki Masabumi Komatsu Mitsutoshi Kitao 《Journal of biosciences》2013,38(4):761-776
To estimate the N2 fixation ability of the alder (Alnus hirsuta (Turcz.) var. sibirica), we examined the seasonal variation in nitrogenase activity of nodules using the acetylene reduction method in an 18-year-old stand naturally regenerated after disturbance by road construction in Japan. To evaluate the contribution of N2 fixation to the nitrogen (N) economy in this alder stand, we also measured the phenology of the alder, the litterfall, the decomposition rate of the leaf litter, and N accumulation in the soil. The acetylene reduction activity per unit nodule mass (ARA) under field conditions appeared after bud break, peaked the maximum in midsummer after full expansion of the leaves, and disappeared after all leaves had fallen. There was no consistent correlation between ARA and tree size (dbh). The amount of N2 fixed in this alder stand was estimated at 56.4 kg ha?1 year?1 when a theoretical molar ratio of 3 was used to convert the amount of reduced acetylene to the amount of fixed N2. This amount of N2 fixation corresponded to the 66.4% of N in the leaf litter produced in a year. These results suggested that N2 fixation still contributed to the large portion of N economy in this alder stand. 相似文献
20.
The abundant species of Calanus that dominate the mesozooplanktonof high North Atlantic latitudes overwinter at depths >500m, when the population loses 7080% of its biomass bypredation and physiological stress. This represents an annualflux of carbon, obtained in the photic zone, into the interiorof the ocean of 274.5 mg C m2 year1, or 0.0018Gt C year1 for the North Atlantic. This is a small valuecompared with the flux of respiratory carbon by diel migrantsin warmer oceans and, when extrapolated to a global flux (0.0120.018Gt C year1 over areas where winter migrations are importantis also small compared with computations of the global sinkingflux of particles through 200 m (1.63.8 Gt C year1or other relevant global carbon fluxes in the oceans. 相似文献