Malle Mandre

Partitioning Of Carbohydrates And Biomass Of Needles In Scots Pine Canopy

The study was aimed at the quantitative evaluation of the temporal and spatial partitioning of non-structural carbohydrates and needle biomass in a canopy of Scots pine (Pinus sylvestris L.) growing in a Myrtillus site type forest stand (predominant in Estonia). The tree canopy was divided into ten equal layers and the material for the spatial partitioning of the investigated characteristics was sampled from all layers. Our findings revealed a significant variation in morphology and in the partitioning of carbohydrates in needles in different layers of the canopy. The study of the temporal dynamics of carbohydrates showed that starch content in needles started to increase in early spring before budbreak, which was accompanied by a decline in soluble carbohydrates. In October, the starch content of needles was low, but the concentration of soluble sugars started to increase attaining a maximum in winter. Regression analysis indicated that before budbreak, the partitioning of soluble sugars in different canopy layers was relatively weakly correlated with the height of the layer; however, a strong correlation was observed for starch. In autumn, when the growth of trees stopped and daily temperatures decreased, the allocation of soluble sugars was correlated with the height of the canopy layer

The partitioning of carbohydrates and the biomass of leaves in Populus tremula L . canopy

Abstract This study was aimed at making a quantitative evaluation of the biomass, carbohydrates and mineral nutrients partitioning in the canopy of aspen (Populus tremula L.) growing in a forest stand. Tree canopy biomass was divided into ten equal horizontal layers and the material for the study was sampled from all canopy layers. The results indicated that the specific leaf mass and the dry matter content increased but the area of leaves decreased toward the top of the canopy. The content of the non-structural carbohydrates depended largely on the position of the leaves in the canopy and the N, P and K contents in the leaves, reaching a maximum in the upper canopy layers better exposed to light. Regression analysis showed a linear relationship between the leaf mass per area and the percentage of dry matter on the one hand and the content of carbohydrates, N, P and K in the canopy on the other.

CHANGING CARBOHYDRATE PARTITIONING IN 6-YEAR-OLD CONIFEROUS TREES AFTER PROLONGED EXPOSURE TO CEMENT DUST

Two-year-old seedlings of Picea abies L., P. glauca L., P. mciriana L., Pinus sylvestris L. and Pseudotsuga menziesii L. were planted in a sample plot influenced by high concentrations of cement dust, and in an unpolluted (control) area in 1990. In 1994, the six-year-old trees were dug up in the pre-bud-break period. A comparative analysis of soluble sugars (glucose, fructose, sucrose, maltodextrines), starch and hemicelluloses contents was carried out and the changes in carbohydrate partitioning were estimated. A decrease in the total content of soluble sugars, mainly of glucose, fructose and maltodextrines, was observed in polluted trees, especially in roots, stems and buds, while the sucrose content increased in different organs. Fluctuations in glucose and fructose contents in roots were in good correlation with these sugars in needles and maltodextrines in stems and shoots. Changes in starch and hemicellulose partitioning between different organs of trees were modest and their directions were highly dependent on species

State of Scots pine (Pinus sylvestris L.) under nutrient and water deficit on coastal dunes of the Baltic Sea

The aim of the present study was to assess the ecophysiological state of Scots pine (Pinus sylvestris L.) growing at different heights on one of the typical coastal sand dunes in the dune field situated in southwestern Estonia. Dependence of the anatomical structure, morphological parameters, nutrients accumulation and biochemical characteristics of needles on the location of the site on the dune and on the concentration of nutrients in soil and in needle tissues was established. Correlation analysis revealed the dependence of chlorophyll a on the concentration of N and Mg in soil as well as in needles. The mesophyll area and chlorophyll concentration in needles were smallest on the top of the dune. The proportion of epidermis in the total needle cross-section area from the top was a little larger than in the needles from the bottom; the epicuticular wax layer on needles decreased towards the top. The length of needles and shoots was the lowest on the top of the dune, where the growth substrate contains notably less nutrients and water than needed for optimum growth of trees. The t test showed statistically significant larger average tree-ring width of the pines growing at the bottom. The pines on the top and at the bottom of the dune were not sensitive to temperature conditions. The radial growth of pines on the top of the dune was positively correlated with the total precipitation of the previous year.

Anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.) growing in a habitat with varying environmental characteristics

Anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.) growing in a habitat with varying environmental characteristics We investigated the influence of a habitat with varying environmental characteristics on the anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.). A dune in South-West Estonia was chosen as the study area because it has extreme environmental characteristics: primitive sandy soil, deficiency of water, heavy winds and high light exposure. Analysis showed that the needles of all age and the current-year shoots of pines growing on the foot of the dune had the largest average cross section, mesophyll and parenchyma areas. The degree of the lignification of needles at the foot, on the slope and on the top of the dune differed distinctly. Intensive lignification of the cellular walls of the xylem was observed in needles and shoots of the pines, growing at the foot, but not in the trees growing on the top of the dune. Analysis showed that the anatomical structure and localisation of lignin, both in needles and in shoots, depend on their age, the trees location (foot, slope or top of the dune) and soil mineral composition. Hariliku männi (Pinus sylvestris) okaste ja võrsete anatoomiline ehitus ja lignifikatsioon ökoloogiliselt erinevates kasvutingimustes Okaste ja võrsete anatoomilist ehitust ja lignifikatsiooni uuriti Tõotusemäe luite jalamil, nõlval ja harjal kasvavatel mändidel. Okaste ja võrsete ristlõigete analüüs näitas, et nende anatoomiline ehitus ja lignifikatsioon sõltuvad puude kasvukohast luitel ja substraadi mineraalsest koostisest. Luite jalamil kasvate mändide okkad ja võrsed olid suurema ristlõike üldpindalaga ja assimilatsioonikoe pindalaga, võrreldes nõlval ja harjal kasvate puude okaste/võrsetega. Luite harjal kasvavate mändide jooksva aasta okkad olid väiksema ksüleemi ja juhtkoe pindalaga, nende mändide jooksva aasta võrsetel aga vastupidi - juhtkimbu ja ksüleemi osa oli suurim. Suuremal osal analüüsitud okastest ja võrsetest oli lignifitseerumisprotsess hästi jälgitav. Ligniini akumulatsioon algab okaste ja võrsete ksüleemi ja epidermi rakukestades. Vanemates okastes ligniini hulk suureneb, kuigi ligniini koguvate kudede pindala ei suurene - jooksva aasta okastes ksüleemi, epidermi ja sklerenhüümi osakaal oli 13,2%, esimese ja teise aasta okastes vastavalt 13,5% ja 12,6%. Luite harjal kasvavatel mändidel oli lignifitseerumisprotsess vähem intensiivne nii okastes kui ka võrsetes, võrreldes luite jalamil ja nõlval kasvavate mändidega.

Short-Term Influence of Clinker Dust and Wood Ash on Macronutrients and Growth in Norway Spruce (Picea abies) and Scots Pine (Pinus sylvestris) Seedlings

The effects of clinker dust and wood ash on Norway spruce and Scots pine seedlings were compared in buried pots. Clinker dust (0.5 kg m−2) and wood ash (0.5 kg m−2) were applied to the surface of a nutrient-poor mineral soil. In the second year, the increase in soil pH by the dust and ash were larger than in the first year. Both alkaline treatments caused a large increase in the needle potassium (K) concentration. An excess of soil K relative to magnesium (Mg) was observed by decreased Mg concentration in needles shortly after treatment. However, Mg concentration in needles stayed in the sufficiency range. Current results confirmed earlier findings that despite a positive effect on base cation nutrition, wood ash has a low potential for increasing the biomass of forest stands on mineral soils due to the N limitation in these soils.

Impact of Alkalisation of the Soil on the Anatomy of Norway Spruce (Picea abies) Needles

In this study, we evaluated the needle anatomy of Norway spruce trees growing on a territory that was exposed to different alkaline dust pollution. The anatomy of the needles of spruce growing on a polluted site in the vicinity of the Kunda cement plant (Northeast Estonia) was compared with the anatomy and physiological state of the needles from an unpolluted site. The needles from polluted sites had a significantly larger average mesophyll area and thicker epidermis. These needles also had significantly smaller average vascular bundles and xylem areas than needles from the unpolluted site. Although in the alkalised growth conditions, the mesophyll area enlarged, the number of damaged mesophyll cells increased, and as a result, the concentration of chlorophylls decreased reducing the photosynthetic potential of trees. Our study indicates that even though cement dust pollution has practically ceased in the area, the alkalised soil is affecting physiological processes in trees for a long time.

Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea

Chemical characteristics of soils in Scots pine forests of Cladina and Vaccinium vitis-idaea site types on coastal dunes of Baltic Sea The coastal dunes of Southwest Estonia have been undergoing a process of stabilisation and are today covered predominantly with Scots pine forests. For the investigation of soils on dunes sampling sites were selected according to topographical positions and forest site types: two sites in Cladina and two sites in Vaccinium vitis-idaea site types on dunes of different heights. The prevailing soils on dunes are Gleyic Podzols, which are generally poor in humus, water and mineral nutrients. Great differences in soil chemical components were found on the foots, slopes and tops of the dunes depending on the height of the dune. The study showed that the concentration of macronutrients (N, K, Ca, Mg) in soil decreased from the foot towards the top. On the other hand, a serious decrease in the nutrient concentration from the O horizon to the BC horizon was typical of the dunes. The soils were generally acidic, with the pH of 3.4-5.5 in the studied sampling sites. The soils were more acidic on the foots of the dune and in the O and A horizons. Mulla iseärasused luitemännikutes Cladina ja Vaccinium vitis-ideae kasvukohatüübis Edela-Eesti rannikumaastikule on iseloomulikud pärast viimast jääaega jääliustiku sulamise setetest moodustunud luited ja rannavallid. Luitemaa looduskaitseala on loodud Antsülusjärve ja Litoriinamere rannaluidete ja nende ümber kujunenud koosluste, aga ka rannaniitude ning ohustatud ja haruldaste liikide elupaikade kaitseks. Luidetel on kujunenud omapärane mullastik ja universaalsed taimekooslused. Käesoleva töö eesmärgiks on anda uusi teadmisi luidete mullahorisontidest ja toitainete sisaldusest seotuna luite kõrguse ja prooviala asukohaga ning põhitähelepanu oli pööratud muldadele Cladina ja Vaccinium vitis-ideae kasvukohatüüpides. Rannametsa piirkonnas valiti 4 luidet, igal luitel 3 proovipunkti: jalamil, nõlva keskosas ja luite harjal. Kaks prooviala (kõrgustega 34 ja 27 m ü.m.p.) asuvad Vaccinium vitis-ideae ja kaks (14 ja 9 meetrit ü.m.p.) Cladina kasvukohatüübis. Proovipunktides määrati erinevad mullahorisondid ja nende tüsedus, igast horisondist võeti proovid pH ja makrotoitainete määramiseks. Luitemuldadele on iseloomulik õhuke huumushorisont (A), mida võis leida ainult luidete jalamil paiknevates proovipunktides, horisondi tüsedus varieerus 2-20 sentimeetrini. Kõduhorisont (O) oli õhuke, vähenedes 4-30 sentimeetrilt luite jalamil 5-10 sentimeetrini luite harjal. Tulemustes ilmnesid olulised erinevused luite jalami, nõlva keskosa ja luite harja mullaproovide keemilises koostises sõltuvalt luite kõrgusest. N, K, Ca ja Mg sisaldus väheneb oluliselt liikudes luite jalamilt harjale. Samuti on luidetele iseloomulik toitainete kontsentratsiooni vähenemine O horisondist BC horisondini. Mullad on tavaliselt happelised (pH 3,4-5,5), kusjuures happelisemad on jalamil paiknevate proovipunktide mullad ning O ja A horisondid.

Disturbance dynamics and ecosystem-based forest management

Ecosystem-based management is intended to balance ecological, social and economic values of sustainable resource management. The desired future state of forest ecosystem is usually defined through productivity, biodiversity, stability or other terms. However, ecosystem-based management may produce an unbalanced emphasis on different components. Although ecosystem-based management respects the ecology of individual ecosystem components or values, it may focus on individual objectives rather than producing an integrated and balanced system. An important part of understanding the complexity of the ecosystem is to understand the role that disturbance, natural and anthropogenic, plays in the proper functioning of that ecosystem.

Development and renewal-conditions of dune pine forests second growth in the lichen and cowberry site type in Southwest Estonia

Edela-Eesti luitemetsade järelkasvu arengust ning uuenemistingimustest sambliku ja pohla kasvukohatüübis On the southwestern coast of Estonia dune pine forest covers approximately 3000 hectares. This area includes coastal pine forests. The dune pine forest natural renewal in Southwest Estonia is the object of research. The natural regeneration of Scots pine (Pinus sylvestris L.) at the cowberry site type and at the lichen site type are observed. The necessary observations were made and primary data were collected in 1999-2006 from 28 sample plots, wherefrom 16 were situated at the lichen and 12 at the cowberry site type. The aim of the present study was to find out how old stand and forest site type influences the growth of second growth (height, height increment, age and number of trees per unit area) and its morphological parameters (length of needles and shoots and their dry mass). Development and renewal-conditions of dune pine forests second growth in the lichen and cowberry site type in Southwest Estonia Ecological dependences of Scots pine second growth in Southwest Estonian coastal pine forests in most common Vaccinium vitis-idaea and Cladina site types were explained. In these 120-190 year old coastal stands, the structure of stand upper layer and formation factors, appearance and condition of second growth and its dependence on old stand density were investigated. During the past decades these stands have been tried to renew by gradual thinning, which in some part has given some positive results. At this moment, in Vaccinium vitis-idaea pine forests, there is growing on an average 2661 and in Cladina pine forests 2556 second growths pine, which height is from some centimetres to 10 meters and more than 85% of these trees are totally viable. Investigation results revealed, that there is a number of various factors, that influence formation and growth of Scots pine natural regeneration, wherefrom the most important is old stands density, which reveals itself by light conditions and root competition. From investigation results may conclude: • In the Cladina site type, density in the range 0,45-0,88 affects second growths increment of height on an average (r = -0,76). In the Vaccinium vitis-idaea site type density affects second growths increment of height mildly (r = -0,45). Increment of height of natural regeneration increases when old stands density decreases. • In the Cladina site type, density influences Scots pine second growths morphological parameters of shoots and needles significantly more than in the Vaccinium vitis-idaea site type. Poorer growth and less productive soil conditions of Cladina site type compared to Vaccinium vitis-idaea site type appeared in smaller increment of height of second growth trees, in smaller length and dry mass of shoots and needles, but in greater density of needles. The conclusion drawn from different comparisons was that narrow clear-cuts have great influence on the natural regenerations growth and number at the Cladina site type. When we sought connections between the old stand density, taking into consideration also narrow clear-cut sample areas with second growths number of trees, height and increment of height, the connections were significantly stronger. In these areas the number of trees and second growths increment of height were considerably higher than in the sample plots, which were under old stands shelter (14, 15 and 27). Clear-cut strips up to 30 m in width with no old forests direct shelter and root competition to second growth create favourable site conditions for natural regeneration. Earlier attention has been drawn to the favourable effect of clear-cut strips on the natural regeneration of heath pine forests. Pine forests with 25 m clear-cut strips have naturally regenerated well in Sagadi and Märjamaa forest districts (Etverk, 2000).