Climate on earth is getting warmer, which effects earth’s energy balance and so forth the ocean and atmospheric circulation.  In many sub-polar regions on the northern hemisphere changes due to warming of the climate can be observed. Some examples that already have been observed are shifts in tree line, towards higher altitudes and latitudes, increased ablation of Swedish glaciers and melting of the permafrost on the Siberian tundra. In Sweden climate change scenarios tell us that it will become warmer and that a higher amount of precipitation in form of rain will be an effect from this. To study climate changes in Sweden, transition zones are useful in order to observe changes in distribution of species and animal populations. This study uses tree rings from Scots Pine (Pinus sylvestris L.) that grow at the tree line in Grövelsjön that is part of the mountains in Dalarna County. By measuring the width of the tree rings, a chronology that is representative for July temperature is made over this area. The method is called dendroclimatology and has generally been used to reconstruct past climate for the last 1000 years.  The results of this study show that the tree ring chronology don’t show a clear increase in temperature for the last century, which could have been expected from an area like this. But the result also show that when instrumentally measured temperature were plotted month by month, the only month with significant up going trend in temperature in this area is April. A temperature change in April does not leave a signal in the tree rings because it is too cold for them to grow that early in the season.

La conca Mediterrània és un territori especialment idoni per estudiar els impactes que tenen les pertorbacions relacionades amb els usos del territori i el canvi climàtic sobre la demografia dels seus boscos. En aquesta regió la disponibilitat d'aigua és un factor limitant en els boscos, on les sequeres són freqüents i es preveu que siguin més recurrents en el futur. La conca Mediterrània representa el límit meridional de distribució d'importants espècies arbòries de l'Hemisferi Nord, i aquestes poblacions són, probablement, particularment vulnerables a l'augment de l'aridesa. En aquest sentit, durant les últimes dècades un augment generalitzat en la defoliació dels boscos i episodis localitzats de mortalitats molt elevades s'han associat a períodes de sequera. D'altra banda, l'expansió i densificació dels boscos després de l'abandonament agrícola i de la gestió forestal tradicional han estat particularment intenses en aquesta regió durant l'últim segle. Aquests canvis poden resultar en un augment de la competència entre els individus pels recursos, amb una tendència pels processos de autotala, exacerbant la vulnerabilitat dels boscos durant episodis de sequera. A més, a la conca Mediterrània el foc determina la dinàmica i els patrons estructurals i paisatgístics de la vegetació, i l'aridesa determina la vulnerabilitat dels boscos al foc. El pi roig (Pinus sylvestris L.) és una de les espècies d'arbre més àmpliament distribuïdes de l'Hemisferi Nord. El límit sud-oest de l'àrea de distribució del pi roig es situa a la península Ibèrica, on es troben poblacions importants als Pirineus i algunes poblacions disperses en localitats més meridionals i seques. Durant el segle XX els boscos de pi roig s'han densificat i la seva àrea de distribució s'ha expandit notablement a causa dels canvis d'usos del sòl i de la gestió forestal. D'altra banda, hi ha indicis que durant les últimes dècades en aquesta regió les poblacions de pi roig estan patint episodis de mortalitat associats a sequera. A més, els focs de copa han afectat alguns dels seus boscos durant els últims anys. Amb aquesta tesi es pretén aprofundir en l’estudi dels patrons demogràfics de creixement, mortalitat, establiment i reproducció dels boscos de pi roig (Pinus sylvestris L.) al seu límit meridional (i sec) en resposta a les pertorbacions (incendis, sequeres, canvis en els usos del sòl), com aquests varien amb els gradients ambientals al llarg de diferents escales espacials i si aquests processos poden originar canvis en la vegetació. Els principals resultats de la tesi són: (1) Els boscos de pi roig a la península Ibèrica són climàticament vulnerables al foc, i aquesta vulnerabilitat podria augmentar substancialment com a conseqüència del canvi climàtic. Aquest fet, sumat a la maca de mecanismes efectius de regeneració de l’espècie, pot dur a canvis ràpids en la vegetació en zones actualment dominades pel pi roig. (2) Els processos de competència i autotala esdevenen els principals factors que expliquen els patrons demogràfics i, per tant, l’abandonament de les activitats agràries i forestals durant el segle XX són la principal pertorbació que explica els processos emergits. Tanmateix, les sequeres i les limitacions abiòtiques estan desencadenant processos de declivi, aparentment en boscos amb una estructura més desenvolupada, i.e. major abundància d’arbres grans. Malgrat que els efectes de la sequera són clars a escala local, i és previsible que es facin més perceptibles en el futur, no es detecta actualment un procés generalitzat de declivi a escala regional. (3) La regeneració del pi roig és en general baixa i, en particular, aquesta és encara menor en zones afectades per episodis de declivi, la qual cosa suggereix que es poden produir canvis en la vegetació a mig termini. Hi ha indicis que aquests canvis poden resultar de l’abandonament agrícola i dels canvis recents en els usos forestals. (4) El declivi a nivell de rodal i la defoliació a nivell d’individu afecten l’esforç reproductiu del pi roig, la qual cosa podria explicar, en part, el seu baix reclutament en zones afectades per episodis de declivi. / The Mediterranean basin is an ideal area to study the impacts of disturbances related to land-use changes and climate change on the demography of forests. In this region, water availability is a limiting factor in forests, where droughts are common and are expected to be more frequent in the future. The Mediterranean basin represents the southern limit of distribution of important tree species in the Northern Hemisphere, and these populations are probably particularly vulnerable to increased aridity. During the last decades a widespread increase in defoliation of forests and localized episodes of high mortality have been associated to drought periods. Moreover, the expansion and densification of forests after agricultural abandonment and traditional forest management have been particularly strong in this region during the last century. These changes may result in increased competition for resources among individuals, with a tendency for self-thinning processes, exacerbating the vulnerability of forests during drought periods. In addition, in the Mediterranean basin, fire determines the dynamics and structural patterns of vegetation, and dryness determines the vulnerability of forests to fire. Scots pine (Pinus sylvestris L.) is one of the most widely distributed tree species in the Northern Hemisphere. The southwestern distribution limit of Scots pine is the Iberian Peninsula, with important populations located in the Pyrenees and some scattered populations in southern and dry locations. There have been important land use changes in the Iberian Peninsula during the last century, including the abandonment of agropastoral activities in mountain areas, the abandonment of forest exploitation, and a large-scale afforestation starting in the 1940s that intensified during the 1950s and has continued albeit at lower rates until recent decades. As a result, stand density has increased in many forests and the range of Scots Pine has expanded noticeably. Moreover, in recent decades Scots pine forest decline has been related to extreme drought episodes in several populations in the Iberian Peninsula, and crown fires have affected some populations. This thesis aims to study the demographic patterns of growth, mortality, reproduction and establishment of Scots pine (Pinus sylvestris L.) at the southern limit (dry) of its distribution in response to disturbances (fires, droughts, changes in land use). The main results of this thesis are: (1) Scots pine forests in the Iberian Peninsula are climatically vulnerable to fire, and this vulnerability could increase substantially as a result of climate change. This fact, added to the lack of effective mechanisms of regeneration, can lead to rapid changes in vegetation in areas currently dominated by Scots pine. (2) Competition and self-thinning are the main factors explaining demographic patterns. Therefore, the abandonment of agriculture and management during the last century are the main disturbances explaining the emerged processes. However, droughts and abiotic constraints are triggering Scots pine decline, apparently in forests with greater abundance of large trees. (3) Scots pine regeneration is lower in declining forests, suggesting that vegetation shifts could occur in the future. These changes could be result of recent land-use changes. (4) Drought stress affects the reproductive effort of individuals, which could contribute to the low recruitment in declining forests.

No description available.

Abstract It has been suggested that pine needles protect themselves against UV-B radiation via anatomical and chemical changes in the epidermal layer. This could lead to growth reductions if more assimilates are allocated to the protection mechanisms in the epidermis at the expense of the photosynthetic area. If the protection is insufficient, the UV-B radiation could cause oxidative stress. Moreover, the UV-B-induced stress could increase year by year and the responses could become cumulative. Therefore, two different UV-B field experiments were conducted at two sites. The first was a long-term experiment on mature, naturally growing Scots pines (Pinus sylvestris L.) in Oulu (65°N), Finland, during the growing seasons 1996–1998 (25% ozone depletion) and the second one was a one-growing-season experiment on Scots pine and loblolly pine (Pinus taeda L.) seedlings in Maryland (39°N), USA, in 1997 (16% and 25% ozone depletion scenarios). In Scots pine seedlings, UV-B treatments decreased the primary needle length at the early stages, but no significant differences were seen in fully-grown needles. In mature Scots pines, the response was opposite and UV-B accelerated needle growth in young needles. This suggests that at the early stage of development, the primary needles of seedlings are more sensitive than the fascicle needles of adult pines. Thus, the developmental stage of the studied organisms must be taken into account. Scots pine seedlings protected themselves against UV-B by increasing the thickness of the cutin layer and the epidermal wall (outer and periclinal walls and anticlinal wall), which features have been connected to xeromorphic structure, and by reducing significantly the cross-sectional, mesophyll and epidermal areas. In mature Scots pines, similar trends towards smaller cross-sectional and mesophyll areas and significantly reduced epidermal + hypodermal area were seen in fully-grown UV-B-treated needles. Loblolly pine responded to supplemental UV-B by producing more phenolic compounds into epidermal cell walls and epidermal lumen, which could have resulted in thicker outer epidermal walls. In both of the studied species, these protection mechanisms were sufficient to prevent growth reductions in fully-grown current-year needles. This demonstrates the difference between the studied species and shows that no general interpretations can be made on the effects of UV-B radiation on conifers. The cumulative effects of UV-B radiation were studied from current-year and current+2-year old needles of mature Scots pines during the third UV-B exposure season. The UV-B stress was observed in the current+2-year old needles of mature Scots pines as a degradation of total glutathione, GSHtot, and a bigger proportion of oxidized glutathione, GSSG%, in July during the third UV-B exposure season. In current-year needles, no increase in GSSG% was seen in either the first or the third season. After the third experimental season in September, the GSHtot levels decreased in UV-B-treated current-year needles. These results suggest that the effect of UV-B is duration-dependent and cumulative. The longevity of mature Scots pine needles at the study site is four to five years, and the effects of UV-B should thus be studied over the whole life span of a needle.

Annotation Il y a plusieurs périodes quad les radioactivité des radionuclides dans l��environement sont grandi . Ces périodes s’ont trouvé à cause des explosions nucléaires et d’avarie de la station atomique de Chernobyl. Les radionuclides se retrouvent dans les plantes avec les emisions d’atmosphere par les surterres partes, avec le fluide de sol par les system de la rasines. Les radionuclides s’accumulent dans les plantes. L’accumulation des radionuclides dans les plantes dépende de la pollutions, du sol type dominant, des particularités chimiques et fisiques des radionuclides, de la forme chimique des radionuclides, du type des plants, des particularités climatiques. Le pin (Pinus sylvestris L.) est très étendu en Lituanie. Très souvent les maladies des champingion et des moisissures attaquent cet type d’arbre. C'est pourquoi nous choisisons le pin (Pinus sylvestris L.), qui est attaqué des maladies des champingion et des moisissures pour les recherches. Nous avons ramassé et traité tels échantillons: du sol, des mousses, des branches, des rasines, des aiguilles, du boi. Dans notre échantillons nous avons déterminé les activités des 226Ra, 232Th, 40K, 137Cs et les facteurs de transfert des radionuclides dans le systèm sol – arbre. Dans les 27 échantillons de bois nous avons déterminé les colonies des champingions. Mais le excitateur de moisissure (Heterobasidion annosum) as déterminé seulement en un échantillon de bois. Nous avons estimé quel est l’influence des... [to full text]

Magistro darbe lyginama vieno paprastosios pušies (Pinus sylvestris L.) klono skirtingų lajos dalių sėklinių palikuonių, augančių Višakio Rūdos bandomuosiuose želdiniuose, genetinė įvairovė remiantis DNR žymenimis ir kokybiniais bei kiekybiniais požymiais. Darbo objektas – paprastosios pušies (Pinus sylvestris L.) sėklinių palikuonių želdiniai iš skirtingų lajos dalies sėklų (viršutinės, vidurinės, apatinės). Darbo metodai – genetinė įvairovė tirta atliekant želdinių kiekybinių ir kokybinių požymių analizę bei jų DNR polimorfizmo tyrimą. Darbo rezultatai. Fenotipinių požymių tyrimai parodė, kad 24 m amžiuje, viršutinės lajos dalies sėkliniai palikuonys pasižymi ženkliai didesniu išlikimu, bet esminiai nesiskiria savo kiekybinių ir kokybinių požymių įvairove nuo apatinės lajos dalies palikuonių. Gali būti, kad fenotipinių požymių įvairovei atsiskleisti trukdo nevienodas medžių išlikimas, kur esant mažesniam išlikimui, susidaro nevienodi tarpai tarp medžių, galėję įtakoti didesnę erdvinę įvairovę radialiniam prieaugiui. 6 chloroplasto DNR(cpSSR) lokusų DNR polimorfizmo tyrimai parodė, kad viršutinės lajos dalies sėklinių palikuonių genetinė įvairovė yra ženkliai didesnė nei vidurines ir apatinės lajos dalių sėklinių palikuonių. Iš 30 skirtingų cpSSR tipų (tėvinių genotipų) 18 buvo aptikti viršutinės lajos dalies palikuonyse, tuo tarpu vidurinėje dalyje – 8, o apatinėje - 10 .Visi 5 proc. savidulkinių individų aptikti tarp apatinės ir centrinės lajos dalies palikuonių (18 vnt.)... [toliau žr. visą tekstą] / The genetic diversity of the progeny from different parts of Scots pine crown of a single clone by quantitative and qualitative traits and DNA polymorphism was investigated in the work of master science. Object of the work - 24 years old progeny from different parts of Scots pine crown of a single clone. The aim of the study - to compare the diversity of quantitative and qualitative traits and DNA polymorphism of24 years old progeny from different parts of Scots pine crown of a single clone by using cpSSR DNA markers. Methods of the work - Survival, stem diameter, stem straightness, flowering, cone yield, barktype,condition,the beginning of activegrowth and other parameters of the seedling progenies were evaluated. The genetic diversity was assessed at six cpDNA loci by the aid of cpSSRs. Study results. The results showed, that the survival of the progeny from the middle and the bottom of the crown was much lower than from the top. However, there were not any significant differences nor in the other traits neither between the variances of the progeny from the different parts of the crown. A reason could be that owing to low survival of the bottom and middle progeny, the remaining trees grew in a wider spacing and this uneven spacing between the treatments disturbed the comparison. cpSSR markers revealed much greater haplotype and allele diversity of the progeny from the top of the crown. Selfing rate was 5; background pollination 50; as much as 28 of the progeny from the... [to full text]

För tallen finns många alternativa slutanvändningsområden, och kraven på virket varierar. Några egenskaper som har stor betydelse är stamrakhet, grengrovlek, grenvinkel och om det finns sprötkvist eller ej. Kvalitetsförsämringen i Sydsveriges tallskogar kan vara ett allvarligt problem och härör bl.a. till ökad produktion och rationaliseringar inom skogsbruket. Lönsamhet har varit målet, men har det skett på bekostnad av kvalitet? För att närmare belysa frågan om förekomsten av tall av god kvalitet syftar denna studie till att bedöma rotstockar i konventionellt skötta och stamkvistade bestånd samt deras potential att växa in i värdefulla klasser eller sortiment. Fältstudien är avgränsad till Bergslagen. I mätningarna har endast rotstock (upp till 3,4 m i längd) av träden bedömts, huruvida de har potential att hålla klass 1-kvalitet, sortiment stamblocks-kvalitet eller sortiment rotstock-kvalitet vid en brösthöjdsdiameter av 320 mm. Andelen rotstockar ≥ klass 1 uppskattades i de stamkvistade bestånden bli 72-94 %, då skötseln också syftat till en värdeökning.  Andelen rotstockar ≥ klass 1 i de konventionellt skötta bestånden uppskattades bli 46-56 %. Med stor sannolikhet kommer ingen av dem dock få växa in i de värdefullaste klasserna. Vanligaste nedklassningssorsakerna är för många kvistar och ibland även i kombination med krök i de konventionellt skötta bestånden samt långkrök i de stamkvistade bestånden. I rapportens teori avhandlas olika sortiment och kvalitetsklasser, och sedan undersöks kvalitetsdanande faktorer bl.a. ekologiska förutsättningar och olika skötselåtgärder. En hög röjningsstyrka kan t.ex. resultera i en grövre diameter på grenar. Likaså har sen röjning inverkan på den grövsta grenens diameter, då den minskar. Det finns alltså en potential att erhålla god virkeskvalitet av tall i våra skogar. Detta är möjligt genom aktiv skötsel, att hålla täta förband, genom att gallra ut lågkvalitativa stammar och stamkvistning. Raka tallar ur vilka kan man utvinna ett högt sågutbyte är och kommer att vara en värdefull resurs i framtiden. / In Sweden the quality of Scots pine (Pinus sylvestris) saw timber has decreased. It is especially due to increased labour cost that has led to rational and effective forest management. This study investigated the quality of Scots pine and the potential to produce high quality stems in 9 stands in Bergslagen, Sweden. Two different stand types were investigated: Pruned stands and conventional managed stands. The outcome was a high percentage of valuable stems in the pruned stands (72-94 %), and 46-56 % in the conventional managed stands. It is possible to produce high quality timber of Scots pine with active management, for example by pruning and careful selection of stems in thinnings.

I litteratursökningen fann vi stöd för två hypoteser, att de överlevande träden efterbrand kunde uppleva en tillväxthämning eller en tillväxtökning.För att utreda detta borrades 88 träd på 5 olika områden, varav hälften var obrända trädi intilliggande bestånd. Därefter macrofotograferades borrspånen för att mätaårsringsbredden digitalt. Datan sammanställdes och analyserades sedan.Resultaten från de enskilda områdena visade tillväxtökning, tillväxtminskning elleringen tillväxtförändring som en brandeffekt. För att undersöka detta vidare sålikställdes brandåret för alla områden och sammanställdes till ett totalt medelvärde,detta påvisade en marginellt positiv effekt av branden.Slutsatsen är att många störande variabler påverkade resultatet, dessa variabler agerar isamverkan för att påverka tillväxten och denna studie lyckades inte isolera brandenseffekt. Den totala sammanställningen visar endast en marginell effekt av branden, detberor på att ett område visade en tillväxtökning och ett annat område visade entillväxtminskning, dessa två tar således ut varandra.

The remnants of the Caledonian Pine Forest represent the north western boundary of the Eurasian Pinus sylvestris (L.) distribution. Remnant populations occupy a diverse range of environments within Scotland, subject to a steep rainfall gradient, and previous investigations have found evidence of local adaptation. Additionally, studies of biochemical and molecular markers have indicated that Scotland’s native pinewoods originated from more than one glacial refugium. Whole-genome-shotgun (WGS) sequencing was employed for the discovery of mitochondrial (mt) variants that may provide further insight into the origins of P. sylvestris populations both in Scotland and mainland Europe. DNA extractions were performed on megagametophyte tissue from Scottish, Finnish, and Spanish populations. Three members of the closely related P. mugo species complex were also sequenced. Using similarity-based approach, 160kbp of putative mitochondrial sequence was recovered by comparison of de novo assembled contigs with the mtgenome of the gymnosperm Cycas taitungensis. In total, 16 novel variants were identified among samples, which may be used in future phylogeographic studies. A study of needle characters was performed for eight native populations of P. sylvestris in an outdoor provenance/progeny trial of 192 saplings. A negative correlation was detected between longitude and the number of stomatal rows present on needle surfaces. It was posited that this may be an adaptive response to lower water availability in eastern pinewoods, possibly in conjunction with increasing altitude. The west coast of Scotland is one of the wettest regions in Europe: western pinewoods may receive in excess of 3,000mm of rainfall in a year, compared with an average of 800mm eastern sites. To determine whether native pinewoods are differentially adapted to waterlogging, a glasshouse based provenance/progeny trial of 432 saplings from nine native populations was undertaken, in which 50% were subject to a long-term waterlogging treatment, and the remainder used as a control. Two studies were then conducted. In the first, responses to the treatment were assessed in terms of phenological and growth traits. Bud flush was delayed in response to waterlogging, and growth was impeded relative to the control. Although population differences were observed, treatment × population interactions were not detected. In the second study physiological traits known to be sensitive to plant stress and water balance were measured at intervals throughout the experiment. Prior to the commencement of the treatment needle δ13C was found to exhibit interpopulation differentiation, and was positively correlated with longitude. This seems likely to represent differential selection for water use efficiency between eastern and western pinewoods. Photochemical efficiency and stomatal conductance were found to be reduced by waterlogging, and needle δ13C was increased. After generalising populations into ‘high’ and ‘low’ rainfall groups (monthly averages of 214.9mm and 72.8mm, respectively), high rainfall populations were observed to maintain consistently higher photochemical efficiency under waterlogging the low rainfall populations. In addition, the low rainfall group exhibited greater variability in response to flooding (in terms of phenotypic and additive genetic variance) which may be indicative of a lack of past selection pressure.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree. The results show a big difference in pollen contamination between the two trees. The tree inside the tent showed a contamination rate of 0% and the tree from the open pollination had a contamination rate of 20,5%. No difference was found in the numbers of different fathers although the selfing rate of 4,26% was higher in the tent than the selfing rate of 2,56% observed in the open pollination environment. These results match the results of other studies done on the same orchard pretty well and therefore tent isolation with a supplementary pollination can be a good way to reduce unwanted pollen contamination.