The effect climate change has on forest trees is a large scaled topic. It is to believe that one of the largest threat to the environment today is global warming (IPPC, 2007). The use of fossil fuels seems to be the big threat with its greenhouse gas (GHG) emission and therefore forest is of interest. Forest contributes in several ways. Forest trees work as a renewable source of numerus materials and as it takes up CO 2 from the greenhouse gasses it gives us oxygen (O2). The important process of photosynthesis, to able production of more trees and creation of more forests, tells us the vitality of understanding the tree physiology to the fullest. The response of photosynthesis to temperature is a central facet of trees’ response to climate change. With its photosynthesis plants play a large role in the carbon cycle as they store the hazardous carbon dioxide helping us humans to deal with problems directly linked to climatic change and in the same time they build up biomass that can be used as a renewable source. To understand, and to find the key, how plants can achieve optimum potential of photosynthesis several observations were made using plant material from fertilized and unfertilized Picea abies. Well acknowledged leaf gas exchange measurements were used to see the limitations of photosynthesis, observing the net CO2 uptake rate (Anet), the maximum Rubisco carboxylation (Vcmax), maximum rate of electron transport for regeneration of RuBP (Jmax) and their unique response to temperatures. For three days observations were conducted at the Slu Asa field research station in Lammhult, Sweden. In addition to gas exchange measurements, nitrogen (N), phosphorus (P) and chlorophyll content was measured in needles of the fertilized and unfertilized P. abies to see if the content somehow made an impact on photosynthetic parameters and the influence nutrients might have on the specific leaf area (SLA). Results from the observations showed that optimum temperature for photosynthesis varies to be by fertilized 22°C and unfertilized 19°C. The net photosynthetic rate responded to the influence by added fertilizers to almost a double, 9.10 μmol m−2 sec−1 than of the unfertilized, 5.36 μmol m−2 sec−1. These results indicate that a fertilized P. abies has a greater potency to capture carbon than of an unfertilized P. abies. The result also reveals the future prospect of adding fertilizer to a P. abies as a potential of growth in biomass as well as a carbon sink when atmospheric CO2 levels rise. There were no great differences in the behaviour between Vcmax and Jmax to the added or non-added fertilized P. abies. Perhaps the fact that given fertilizer contained both nitrogen and phosphorous could have in their combinations influenced the sensitivity of the relationship between them two and therefore also the result. The presence of N and P in the fertilized P. abies affected the concentration of chlorophyll positively, paving the way for photosynthesis, accumulated biomass and possibly for trees defence against abiotic stress factors.

Syftet med studien var att beskriva och analysera hur Sydveds certifieringsprocess upplevs av företagets virkesleverantörer. Studien genomfördes som en enkätundersökning via post och e-post. De frågeställningar som utgjorde stommen av arbetet handlade huvudsakligen om upplevelsen kring certifieringsprocessen, virkesleverantörernas kunskap om certifiering, motiv till certifiering och hur dessa påverkar upplevelsen av certifieringsprocessen. Fokus låg även på huruvida den geografiska spridningen hade någon betydelse för upplevelsen liksom om virkesleverantörerna upplevde ett behov av en förändring i certifieringsprocessen. Sammanfattningsvis visade resultaten främst på en förbättringspotential gällande återkoppling och kunskap. Det som Sydved rekommenderas att utveckla är olika delar av certifieringsprocessen där tyngdpunkten bör ligga på att få ett enhetligt sätt att jobba på inom organisationen. Hela certifieringsprocessen, från introduktion till revision och återkoppling bör ha tydliga riktlinjer, då kedjan inte är starkare än sin svagaste länk.

Scots pine (Pinus sylvestris L.) form a large part of Swedish forestry and has many alternative end-use areas with different requirements for quality. The ability to influence the quality is high in the initial planting and juvenile forest phase, as studies have shown relationships between good quality and dense planting, where competition between trees has a good impact on timber quality. Competition can also be achieved by shading from above, through seed trees or multi-layered forest. Interest in continuous cover forestry grows, and investigating differences in future timber quality between layered and clear cutting treatments can therefore be valuable. Such a method is “Naturkultur”, which aims to optimize the net present value at every point in the forest. The purpose of this study is to highlight the question of whether layered forests methods similar to “Naturkultur” can be used for higher timber quality in pine forests in a cleaning trial in southern Östergötland, Sweden. The goal is to find out if any difference in timber quality exists in the future butt log between the different cleaning treatments, layered (Uneven) and conventional (Even). The survey was limited to studying only the Kråkerödjan pre-commercial thinning trial, located on the property Kråkerödjan between Småland and Östergötland. Parameters for quality estimation were delimited to knot quantity and knot thickness. In order to answer the purpose, a field survey was conducted with quantitative assumptions where data about stem quantity, tree species distribution, height, diameter, height of the living crown, number of knots and diameter for the thickest knot from the base of the trunk up to 2 m on the trunk were collected. The result showed that the number of stems per ha was significantly higher in Uneven than in Even while the volume was next to the same. The average diameter was about 4 cm in Uneven and about 10 cm in Even. The tree species distribution was the same for trees with a diameter > 5 cm a breast height (bh) in both parcels,> 95% pine. For trees <5 cm bh, the distribution in Uneven was 14 % pine, 10 % spruce and 76 % deciduous, in Even there were almost exclusively deciduous trees. When examining pine > 5 cm at bh, there was a significant difference in the knot quantity with fewer knots/m in Uneven than in Even. The thickest knot was smaller in Uneven than in Even, but the difference was only significant when the data without dominants was examined. The thickest knot was slightly smaller relative to the diameter of the trunk in bh in Uneven but the difference was not significant. The average diameter in pine > 5 cm at bh was slightly less in Uneven, 10.7 cm, than in Even, 10.8 cm. The survey gives an indication that the layered forest according to the method of “Naturkultur” in the parcel Uneven, where dominants shades smaller trees, may be used for a better timber quality in pine in the investigated premises. However, the results are not sufficiently clear, if this is due to the fact that the quality difference is small or if it is because quality differences have not yet occurred V cannot be read in the survey. Estimating timber quality early in the rotation period is difficult as a lot can happen until final felling. However, the survey has been valuable as more data is needed in the area in question. Follow-up of the survey is needed to further explore the relationships between stock treatments and quality development.

No description available.

Detta examensarbete utfördes under våren 2017 på uppdrag av Södra skogsägarna, för att undersöka om höstplantering av tall ger ett bra föryngringsresultat och kan ses som ett likvärdigt alternativ till att plantera på våren. Traditionellt sett utförs den största delen av planteringar på våren men för att få en jämnare arbetsfördelning över året är det intressant att undersöka om höstplantering av tall fungerar. Undersökningen är utförd som en survey studie där trakter som planterades på hösten 2014 och trakter som planterades på våren 2015 låg till grund för datainsamlingen. Totalt gjordes det uppföljning på 38 trakter där hälften är vårplanterade och hälften är höstplanterade. Trakterna är sedan jämförda parvis med avseende på planttyp, ståndortsindex, viltbehandling, markfuktighet och blockighet. På varje trakt lades det ut 20 provytor med radien 2,82 vilket ger en provyta på 25 m2. I varje provyta mättes för varje planta; rothalsdiameter, toppskottslängd, totallängd, eventuella skador och eventuella avgång och avgångsorsak Höstplantering av tall hade en högre avgång än vårplanteringarna och snytbaggen var den skadegörare som orsakade störst avgång, följt av vilt och torka. Plantan växte något bättre på de trakter som var vårplanterade, men det var bara toppskottstillväxten som var signifikant längre vid vårplantering. Snytbaggeangreppen var lika omfattande vid både vår- och höstplantering medan viltbetningen var dubbelt så stor på de höstplanterade trakterna. / This degree project was conducted in spring 2017, commissioned by Södra forest association, to investigate whether autumn planting of pine gives a good regeneration result and can be seen as an equivalent alternative to planting in spring. Traditionally, most of the plantings is completed in spring, but in order to achieve a more even distribution of labor over the year, it is interesting to investigate whether or not the autumn planting of pine can be successful. The survey was carried out as a survey study, where plants planted both in autumn 2014 and in spring 2015, formed the basis of data collection. A total of 38 sites were investigated, half of study object were planted in spring and half in autumn Sites were then compared in pairs regarded to plant type, site index, game treatment, soil moisture and blockiness. On each site 20 plots were laid out with a radius of 2.82, which gives a sample area of 25 m2. In each sample area following characteristics for each plant were measured; stem diameter, leeding shot length, total length, possible damage and possible dead plants and cause of plant death. Autumn planting of pine had a higher mortality than spring plantations, and the pine weevil caused highest mortality, followed by wildlife grazing and drought. The plantation grew slightly better for spring-planted seedlings, but it was only the leeding shot length that had a significant higher growth. The damage caused by pine weevil was similar for planting in autumn and spring, while the wildlife grazing was twice as high in autumn-planted areas compared to the spring planted.

Skogen innehåller höga värden i form av naturvärden och forn- och kulturlämningar. Dessa måste skyddas när skogen brukas för ekonomisk vinning och hur det ska ske framgår främst i arbetsbeskrivningen för varje objekt, kallat traktdirektiv. För att se var bristerna finns har inköpare/planerare samt maskinförare/entreprenörer intervjuats. En mall för utformandet av traktdirektiven skulle underlätta för alla och gynna de höga värdena i skogen.

Tall (Pinus sylvestris) är ett viktigt vinterfoder för älgen (Alces alces), som är ett uppskattat jaktvilt i Sverige. Tall är också ett av de två absolut viktigaste trädslagen för Sveriges timmer- och massavedsproduktion. När betestrycket på tallungskog blir för högt, tenderar skogsägarna att föryngra tallbestånd med gran (Picea abies), vilket är mindre begärligt för älgen att beta än tall. Konsekvenserna blir en felaktig ståndortsanpassning och att fodertillgången minskar för älgen. Biologisk mångfald påverkas också negativt, då betestrycket på andra trädslag såsom rönn, asp, sälg och ek blir högt. Med världens högsta älgstam sett till skogsmarksareal, skapas stor debatt i Sverige kring älgstammens förvaltning och lämpliga storlek, mellan skogsägare som vill ha ett lönsamt skogsbruk och älgjägare som vill ha en stor älgstam för jakt. En älgstam i balans med fodernivån är bra för både viltet, mångfalden, miljön, samhället, skogsbruket och viltförvaltningen. Syftet med studien var att jämföra skogsägares och jägares syn på betesskador och hur de värderar konsekvenserna av dessa. Målet med studien var att kunna tillhandahålla ett underlag, som kan vara till nytta för älgförvaltningsorgan. Metoden som valdes var en enkätundersökning där kvantitativa data samlades in. Enkäten bestod av totalt 12 frågor, där fråga 7 bestod av flera delfrågor. Studiens urval gjordes som kluster- och bekvämlighetsurval, där totalt 304 enkäter samlades in och svaren från 258 enkäter användes, från skogsägare och jägare som var aktiva i Jönköpings län. Enkäten besvarades av tre olika fördefinierade grupper vilka definierades som jägare som inte äger någon egen skog, skogsägare som jagar och skogsägare som inte jagar. Gruppernas enkätsvar jämfördes med statistiska analyser. Resultatet visade att skogsägares och jägares syn på förekomsten av betesskador skilde sig signifikant. Jägare som inte äger någon egen skog bedömde betesskadeförekomsten som lägst, medan skogsägare som inte jagar bedömde förekomsten som högst. Skogsägare som jagar låg mellan de andra två grupperna. Resultatet visade också att det fanns ett signifikant samband mellan synen på betesskadors omfattning och hur stor vinterstam av älg per 1000 ha man tyckte var lämplig, där respondenterna önskade en lägre älgstam ju högre de bedömde förekomsten av betesskador. Studien visar att älgförvaltningsrepresentanters bakgrund som skogsägare eller jägare påverkar synen på älgstammens lämpliga storlek, eftersom de bedömer förekomsten av betesskadors omfattning olika, liksom betesskadornas konsekvenser. Älgförvaltningsgruppers fördelning av representanter bör därför spegla olika gruppers intressen för att sträva efter acceptans. / Scots pine (Pinus sylvestris) is an important food source for the moose (Alces alces) during winter. Scots pine is also one of the most important tree species for the Swedish timber- and pulpwood industry. The debate between hunters and forest owners, their thoughts about the magnitude of the moose population, and the extent of browsing damage, is background to this study that examined how the groups forest owners who hunts, forest owners who doesn’t hunt and hunters who doesn’t own any forest land thought about browsing damages and its consequences in Jönköping County, Sweden. Data was collected using a questionnaire and analyses were made on answers from 258 respondents. The results showed that the assessment of the extent of browsing damage differed significantly between the groups, where forest owners who doesn’t hunt assessed the extent of browsing damage the highest, hunters who doesn’t own any forest land assessed the extent as lowest, while forest owners who hunt was intermediate between the two other groups. The results also showed that there was a relation between how the respondents assessed the extent of browsing damage and their thoughts about how large the moose population should be.

The study examined the goal fulfillment in edge zones along rivers and lakes in precommercial thinning stands based on national targets which is the basis for Swedish forestry. Pre-commercial thinning has a major impact on the future forest, as it determines how the tree species distribution will turn out. The study was conducted as a field study in February 2018 based on 30 precommercial thinning sites, aged 5–15 years, in connection to rivers and / or lakes. Of these, 25 rivers and five lakes were surveyed. 22 of the surveyed stands were privately owned and 8 were company-owned forests. The edge zones had between 0–100% shadowing of the water surface. Few sites with soil damage were detected and also a varying amount of tree species and deadwood. The most common deadwood was standing and lying dead wood with a diameter of 10 cm for both company and privately-owned forests. The percentage of number of stems per ha of deciduous trees in the edge zones was 52%, Norway spruce 41% and Scots pine 7% respectively. Within the edge zones, the sample areas closest to rivers and lakes had 55% of number of stems per ha deciduous trees, 40% spruce and 6% pine. In the sample areas closest to the stand, the number of deciduous trees was 48%, spruce 44% and pine 9%. Company-owned forests had more spruce (59%) along the waterfront compared to privately owned forests, who had a significantly higher proportion of deciduous trees (61%). By actively working with the composition of the edge zones, creating deadwood, saving trees for shadow and by thinning dense areas, particularly spruce-dominated, increased biodiversity can be achieved. Dense, spruce-dominated areas are those areas where the goal fulfillment is insufficient in many places.

För att Sverige till år 2050 ska kunna vara fossilfritt och oberoende av råvaruimport samt bioenergi från skogen, måste nettotillväxten på den virkesproducerande marken öka rejält.  Syftet med studien var att undersöka vilka kunskaper privata skogsägare har om åtgärder för att öka tillväxten i skogen. Även om de har något incitament för att öka tillväxten i sitt skogsbruk.  Urvalet var tio privata skogsägare i Västerbottens län och genomfördes som en kvalitativ intervjuundersökning.  Resultatet visade att mer än hälften av skogsägarna i studien saknade kunskap om huruvida, skyddsdikning, dikesrensning och användningen av främmande trädslag påverkar tillväxten i skogen. 50 % av skogsägarna i studien kunde beskriva att de saknade incitament för att öka tillväxten i sin skogsskötsel.  Politiska styrmedel och en tydlig skogspolitik var de incitament som skulle kunna påverka skogsägarna att utföra en intensiv skogsskötsel och nyttja skogliga åtgärder för att öka tillväxten ytterligare.

In tropical regions, climate change is predicted to lead to increased drought frequency and intensity. The extent to which this will shift the functional diversity of tropical tree communities is unknown due to a limited understanding about the response of seedlings to variable soil moisture. We addressed this issue using an experimental approach in the Luquillo Experimental Forest, Puerto Rico. We exposed seedlings of eight tree species, representing different successional stages, to an experimental soil moisture gradient. We evaluated (1) How species mean trait values relate to species-specific demographic responses to drought, (2) How intraspecific variation in functional traits relates to a soil moisture gradient, (3) The extent to which demographic response to short-term experimental drought mirrored long-term demographic response of seedlings to natural variation in soil moisture. Growth and survival of species with more `conservative` functional strategies tended to be more sensitive to a change in soil moisture and more tolerant to drought compared to species with more `acquisitive` strategies. In addition, traits of individual seedlings within species varied with respect to soil moisture, suggesting a potential role for phenotypic plasticity in response to drought. Specifically, this response was significant for three species (Inga laurina, Guarea guidonia, Schefflera morototoni) and was primarily associated with relative carbon investment in leaves and roots. Species demographic responses to soil moisture in experimental and long-term studies were weakly positively correlated but more variables are at play under natural conditions, which partly decouples these responses. Overall, our results suggest that tree species with `conservative` functional strategies are likely to become more common under increasing drought frequency and intensity in the Luquillo Mountains of Puerto Rico. However, understanding the broader implications of our findings will require considering the effects of other disturbances, including hurricanes, which may have contrasting effects. Furthermore, intraspecific variation in functional traits is likely to influence how the seedlings of tropical tree species cope with drought.