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1.
This paper elucidates nutrient dynamics in oak forests previouslyinvestigated for dry matter dynamics. The nutrient concentrationsin different life forms were of the order: herb > shrub >tree, whereas the standing state of nutrients were of the order:tree > shrub > herb. Soil, litter and vegetation, respectively,accounted for 32·498·0 %; 0·33·5%, and 10·266·6 % of the total nutrientsin the system. Considerable reductions (8·541·7%)in concentrations of nutrients in leaves occurred during senescence.The uptake of nutrients by vegetation, and also by differentcomponents with and without adjustment for internal recycling,has been calculated separately. Annual transfer of litter (above+ below ground) to the soil by vegetation was 115·9187N, 7·515·6 P, 122·7195·1Ca, 36·148·8 K and 2·885·16Na kg ha1 yr1. Turnover rate and turnover timefor different nutrients ranged between 0·660·84yr1 and 1·191·56 yr1, respectively.Compartment models for nutrient dynamics have been developedto represent the distribution of nutrient contents and net annualfluxes within the system. Quercus leucotrichophora forest, Q.floribunda forest, Q. lanuginosa forest, Nutrient concentration, standing state, uptake, internal cycling, turnover 相似文献
2.
This paper elucidates nutrient dynamics in a pine forest, previouslyinvestigated for dry matter dynamics. The nutrient concentrationsin different life forms were of the order: herb > shrub >tree whereas the standing state of nutrients were of the order:tree > shrub > herb. Soil, litter and vegetation respectivelyaccounted for 38·182·2, 2·43·7and 15·458·2 per cent of the total nutrientsin the system. Considerable reductions (5269 per cent)in concentrations of nutrient in needles occurred during senescence.The uptake of nutrients by vegetation, and also by differentcomponents with and without adjustment for internal recycling,has been calculated separately. Annual transfer of litter tothe soil by vegetation was 76·21 N, 6·25 P, 57·24Ca, 14·22 Mg, 19·92 K and 1·92 kg ha1Na. Turnover rate and turnover time for different nutrientsranged between 0·400·64 and 1·562·50year, respectively. Compartment models for nutrient dynamicshave been developed to represent the distribution of nutrientcontents and net annual fluxes within the system. Nutrient concentration, standing state, uptake, internal recycling, nutrient return, turnover, nutrient cycling 相似文献
3.
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
4.
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
5.
Structure and Function of an Age Series of Poplar Plantations in Central Himalaya. II Nutrient Dynamics 总被引:2,自引:1,他引:1
This paper elucidates nutrient dynamics in 5- to 8-year-oldpoplar (Populus deltoides) clone D121 plantations previouslyinvestigated for dry matter dynamics. The nutrient concentrationin different layers of the vegetation were in the order: tree> shrub > herb, whereas the standing state of nutrientswere in the order: tree > herb > shrub. Soil, litter andvegetation, respectively, accounted for 80-89, 2-3 and 9-16%of the total nutrients in the system. Considerable reductions(trees 42-54, shrubs 31-37 and herbs 15-23%) in concentrationof nutrients in leaves occurred during senescence. The uptakeof nutrients by the vegetation and also by the different components,with and without adjustment for internal recycling, has beencalculated separately. Annual transfer of litter nutrient tothe soil by vegetation was 113·7-137·6 N, 11·6-14·6P and 80·1-83·2 K kg ha-1 year-1. Turnover rateand time for different nutrients ranged between 0·72-0·89year-1 and 1·12-1·39 years, respectively. Thehigh turnover rate of litter on the forest floor indicates thegreater productivity of the stands, which was due to the higherdry matter dynamics and nutrient release for the growing vegetation.The nutrient use efficiency in poplar plantations ranged from159-175 for N, 1405-1569 for P and 295-332 for K. Compared withEucalyptus, there was a higher proportion of nutrient retranslocationin poplars largely because of higher tissue nutrient concentrations;this indicates lower nutrient use efficiency as compared tothe eucalypt plantation. Compartment models for nutrient dynamicshave been developed to represent the distribution of nutrientpools and net annual fluxes within the system.Copyright 1995,1999 Academic Press Populus deltoides plantations (Clone D121), nutrient retranslocation, net nutrient uptake, nutrient use efficiency, nutrient cycling, nutrient pool, nutrient fluxes 相似文献
6.
This paper deals with nutrient dynamics in horse chestnut, silverfir and kharsu oak forests in a high altitude region of CentralHimalaya. In general, the nutrient concentrations in differentlife forms were of the order: herb > seedling > shrub> sapling > tree, whereas the standing state of nutrientswere of the order: tree > herb > shrub > sapling >seedling. Of the total nutrients in the system, soil litterand vegetation, respectively accounted 66·5, 0·6and 32·9% in horse chestnut, 61·4, 0·8and 37·8% in silver fir, 58·1, 0·8 and41·1% in kharsu oak forests. Considerable reductionsin concentrations of nutrients in leaves occurred during senescence.Annual transfer of litter (above-ground+below-ground) to thesoil by vegetation of all forests ranged from 68-163 for N,4-7 for P, 26-48 for K, 62-150 for Ca and 2-4 kg ha-1 year-1for Na. Turnover time for different nutrients ranged between1·41 and 1·75 years for horse chestnut, 1·33and 2·13 years for silver fir, and 1·32 and 1·75years for kharsu oak forests. The distribution of nutrient contentsand net annual fluxes within the system have been developedto represent nutrient dynamics in compartment models.Copyright1995, 1999 Academic Press Standing state, turnover, retranslocation, nutrient concentration, internal cycling, uptake 相似文献
7.
The present paper reports on the forest floor biomass, litter fall, nutrient return and turnover of organic matter in a Pinus roxburghii forest in Kumaun Himalaya. Peak values of fresh leaf litter, partially decomposed litter and wood litter on the forest floor occurred in April, May and September, respectively. The relative contribution of partially decomposed material to total forest floor biomass remained greatest throughout the annual cycle. The biomass of herbaceous vegetation was maximal in September with a total annual net production of 151 g m-2. The total annual litter fall was 895 g m-2, of which tree, shrub and herb litters accounted for 82.4%, 0.6%, and 16.8%, respectively. Annual nutrient return in kg ha-1 through litter fall amounted to 278.6 ash, 73.9 N, 5.5 P, 79.7 Ca, 15.1Mg, 20.7 K and 3.6Na. The turnover rate for tree litter was 48% and that for various nutrients on the forest floor ranged between 40–79%. 相似文献
8.
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
9.
Nutrient translocation in chestnut tree stemwood was calculatedfrom the distribution of nutrient content throughout the tissuelife-span. The dynamics of internal translocation were followedduring the crop rotation by means of an age series of five coppicedstands (219 years). N, P, K, Ca and Mg contents in treerings were estimated from the concentrations along a verticaland radial gradient and from the ring volume obtained usingstem ring analysis.Real nutrient translocation was calculatedstepwise between successive stages in the age series;apparenttranslocation was computed on a complete tree rotation by comparingthe initial content just after the ring was formed with themineral content in the oldest stand. There was a marked translocationof N, P, K and Ca when the rings were physiologically-activetissues. Real translocation of N, P and K (but not Ca) increasedwith stand age, obviously in parallel with the enlarged stemwoodbiomass reaching 23.2 and 20.6 kg ha-1for K and N in the lastyears of rotation, nearly 5 kg ha-1for Mg and about 3 kg ha-1forCa and P. Potassium was the most mobile element since translocationreached 60% of the total amount immobilized in the stemwoodat the end of the rotation, whereas values for N, P and Mg wereapproximately 25% and 10% for calcium. Total apparent translocationreached respectively 39.2 and 32.4 kg ha-1for K, N, approximately12 and 7 kg ha-1for Mg and Ca and only 4.4 kg ha-1for P. Totalapparent translocation as a percentage of total wood immobilizationwas 114% for K, 83% for Mg, 63% for P, but only 39% for N and24% for calcium. Translocation; nutrient content; stemwood; tree ring; coppice; age series; dynamics; chestnut tree; Castanea sativa Miller 相似文献
10.
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
11.
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
12.
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
13.
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
14.
The nutrient concentrations and contents of the under-storeyspecies were estimated for a series of Pacific North-west Douglas-fir[Pseudotsuga menxiessii (Mirb.) Franco] stands ranging in agefrom 9 to 95 years. Analyses were carried out for ash, N, P,K, Ca, Mg, Mn, Fe, Zn and Na and significant differences innutrient concentrations were found to exist between species;species rejecting certain nutrients and accumulating others.General trends for mean concentrations of some nutrients areassociated with stand maturity in that ash, K and Mg decline,P and Mn increase and N and Ca reaches a peak at 2030years and then declines. The nutrient contents (kg ha1)of the under-storey component of the stands are presented andtrends discussed. Mineral nutrient content, under-storey vegetation, Pseudotsuga menziessii stands, Douglas-fir 相似文献
15.
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
16.
Dynamics of Nutrient Translocation in Stemwood across an Age Series of a Eucalyptus Hybrid 总被引:1,自引:0,他引:1
Laclau Jean-Paul; Bouillet Jean-Pierre; Ranger Jacques; Joffre Richard; Gouma Raphael; Saya Aubin 《Annals of botany》2001,88(6):1079-1092
Despite the continuous nature of growth of eucalyptus hybridsin Congo, taper functions fitted to stem profiles of one clonethroughout stand development, combined with annual tree measurements,made it possible to locate accurately the position of annualrings in stems. Annual rings were identified on discs of woodsampled every 4 m in four trees cut from 1-, 2-, 3-, 4-, 5-,6- and 7-year-old stands. Chemical analysis, performed individuallyfor each ring per level and per tree sampled, made it possibleto quantify the changes in nutrient content of the rings duringstand development. Nutrient translocation in stemwood was thuscalculated in a stepwise manner between trees of two successiveages. The cumulated nutrient translocations in stemwood fromthe 1-year-old stage to the 6-year-old stage amounted to 18·5kg ha-1N, 4·2 kg ha-1P, 38·8 kg ha-1K, 1·5kg ha-1Ca and 3·2 kg ha-1Mg. They represented 11, 18,121, 6, and 15% of the amounts of N, P, K, Ca and Mg accumulatedin stemwood, respectively, at the 7-year-old stage (loggingage). Negative translocations of N, P, Ca and Mg in stemwoodbetween 6 and 7 years might indicate an improvement in the nutritivestatus of the stand at the end of the rotation. Much translocationof K in stemwood suggests that this process might be involvedin the high use efficiency of this element. Copyright 2001 Annalsof Botany Company Translocation, stemwood, ring, nutrient, Eucalyptus, age series 相似文献
17.
The seasonal dynamics of forest floor biomass, pattern of litter fall and nutrient return in Central Himalayan oak forests are described. Fresh and partially decomposed litter layers occur throughout the whole year in addition to herbaceous vegetation. The highest leaf litter value is found in April and May and the minimum in September. Partially and largely decomposed litter tended to increase from January to May with a slight decline in June. The wood litter peaked in March and April. The relative contribution of partially decomposed litter to the forest floor remains greatest the year round. The maximum herbaceous vegetation development was found in September with a total annual net production of 104.3 g m-2yr-1. The total calculated input of litter was 480.8 g m-2yr-1. About 68% of the forest floor was replaced each year with a subsequent turnover time of 1.47 yr. The total annual input of litter ranged from 664 (Quercus floribunda site) –952 g m-2 (Q. lanuginosa site), of which tree, shrub and herbaceous litter accounted for respectively 72.0–86.3%, 6.4 – 19.4% and 5.2 – 8.6%. The annual nutrient return through litter fall amounted to (kg ha-1) 178.0 – 291.0 N, 10.0 – 26.9 P, 176.8 – 301.6 Ca, 43.9 – 64.1 K and 3.98 – 6.45 Na. The tree litter showed an annual replacement of 66.0 – 70.0%, for different nutrients the range was 64 and 84%. 相似文献
18.
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
19.
Changes in the Above- and Below-ground Biomass and Nutrient Pools of Ground Vegetation After Clear-cutting of a Mixed Boreal Forest 总被引:3,自引:0,他引:3
Marjo Palviainen Leena Finér Hannu Mannerkoski Sirpa Piirainen Michael Starr 《Plant and Soil》2005,275(1-2):157-167
Ground vegetation may act as a sink for nutrients after clear-cutting and thus decrease leaching losses. Biomass and nutrient
(N, P, K, Ca) pools of ground vegetation (mosses, roots and above-ground parts of field layer) were determined one year before
and five years after clear-cutting of a Norway spruce (Picea abies (L.) H. Karst.) dominated boreal mixed forest stand in
eastern Finland (63°51′ N, 28°58′ E). Before clear-cutting the average biomass of ground vegetation was 5307 kg ha−1, with nutrient contents of 46.9 kg N ha−11, 4.1 kg P ha−11, 16.2 kg K ha−11 and 13.9 kg Ca ha−11. The biomass and nutrient pools decreased after clear-cutting being lowest in the second year, the biomass decreasing by
46–65% in the cut plots. The nutrient pools decreased as follows: N 54–72%, P 36–68%, K 51–71% and Ca 57–74%. The decrease
in ground vegetation nutrient uptake, and the observed reduced depth of rooting may decrease nutrient retention after clear-cutting
and decomposing dead ground vegetation is a potential source of leached nutrients. These negative effects of clear-cutting
on the nutrient binding capacity of ground vegetation was short-lived since the total biomass and nutrient pools returned
to pre-cutting levels or were even greater by the end of the 5-year study period. 相似文献
20.
Development of ground vegetation biomass and nutrient pools in a clear-cut disc-plowed boreal forest
Marjo Palviainen Leena Finér Ari Laurén Hannu Mannerkoski Sirpa Piirainen Michael Starr 《Plant and Soil》2007,297(1-2):43-52
Nutrient leaching from forest substrate after clear-cutting and subsequent soil preparation is strongly influenced by the
capacity of ground vegetation to sequester the released nutrients. We studied the rates and patterns of biomass and nutrient
accumulation in ground vegetation growing on ridges, in furrows and on undisturbed surfaces for 2–5 years after disc-plowing
in eastern Finland. The biomass of mosses on ridges remained significantly lower than that in furrows and on undisturbed surfaces.
Field layer biomass on ridges and in furrows was significantly lower than on undisturbed surfaces throughout the study period.
Field layer biomass increased more on ridges than in furrows. Root biomass on ridges and undisturbed surfaces was considerably
higher than in furrows. Five years after disc-plowing, total biomass and nutrient pools for ridges (biomass 4,975 kg ha−1, N 40 kg ha−1, P 5 kg ha−1, K 20 kg ha−1 and Ca 18 kg ha−1) and undisturbed surfaces (biomass 5,613 kg ha−1, N 43 kg ha−1, P 5 kg ha−1, K 22 kg ha−1 and Ca 18 kg ha−1) were similar, but considerably lower for furrows (biomass 1,807 kg ha−1, N 16 kg ha−1, P 2 kg ha−1, K 10 kg ha−1 and Ca 6 kg ha−1). Ridges covered 25% of the area, furrows 30 and 45% was undisturbed surfaces. Taking into account the proportion of each
type of surface, values for the whole prepared clear-cut area were 4,312, 34, 4, 18 and 14 kg ha−1 for biomass, N, P, K and Ca, respectively. Biomass and nutrient pools had not returned to uncut forest levels at the end
of the 5-year study period. The results indicate that mosses and field layer vegetation respond differently to soil preparation,
that the development of biomass on ridges, in furrows and on undisturbed surfaces proceeds at different rates, and that the
biomass and nutrient uptake of ground vegetation remains below pre-site preparation levels for several years. However, ridges,
which are known to be the most susceptible to leaching, revegetate rapidly.
Responsible Editor: Tibor Kalapos. 相似文献