Estimation of local forest attributes, utilizing two-phase sampling and auxiliary data

This thesis examines the feasibility of a forest inventory method based on two-phase sampling in estimating forest attributes at the stand or substand levels for forest management purposes. The method is based on multi-source forest inventory combining auxiliary data consisting of remote sensing imagery or other geographic information and field measurements. Auxiliary data are utilized as first-phase data for covering all inventory units. Various methods were examined for improving the accuracy of the forest estimates. Pre-processing of auxiliary data in the form of correcting the spectral properties of aerial imagery was examined (I), as was the selection of aerial image features for estimating forest attributes (II). Various spatial units were compared for extracting image features in a remote sensing aided forest inventory utilizing very high resolution imagery (III). A number of data sources were combined and different weighting procedures were tested in estimating forest attributes (IV, V). Correction of the spectral properties of aerial images proved to be a straightforward and advantageous method for improving the correlation between the image features and the measured forest attributes. Testing different image features that can be extracted from aerial photographs (and other very high resolution images) showed that the images contain a wealth of relevant information that can be extracted only by utilizing the spatial organization of the image pixel values. Furthermore, careful selection of image features for the inventory task generally gives better results than inputting all extractable features to the estimation procedure. When the spatial units for extracting very high resolution image features were examined, an approach based on image segmentation generally showed advantages compared with a traditional sample plot-based approach. Combining several data sources resulted in more accurate estimates than any of the individual data sources alone. The best combined estimate can be derived by weighting the estimates produced by the individual data sources by the inverse values of their mean square errors. Despite the fact that the plot-level estimation accuracy in two-phase sampling inventory can be improved in many ways, the accuracy of forest estimates based mainly on single-view satellite and aerial imagery is a relatively poor basis for making stand-level management decisions.

Digitoitujen väri-infrailmakuvien numeerinen monikuvatulkinta metsäninventoinnissa

The use of remote sensing imagery as auxiliary data in forest inventory is based on the correlation between features extracted from the images and the ground truth. The bidirectional reflectance and radial displacement cause variation in image features located in different segments of the image but forest characteristics remaining the same. The variation has so far been diminished by different radiometric corrections. In this study the use of sun azimuth based converted image co-ordinates was examined to supplement auxiliary data extracted from digitised aerial photographs. The method was considered as an alternative for radiometric corrections. Additionally, the usefulness of multi-image interpretation of digitised aerial photographs in regression estimation of forest characteristics was studied. The state owned study area located in Leivonmäki, Central Finland and the study material consisted of five digitised and ortho-rectified colour-infrared (CIR) aerial photographs and field measurements of 388 plots, out of which 194 were relascope (Bitterlich) plots and 194 were concentric circular plots. Both the image data and the field measurements were from the year 1999. When examining the effect of the location of the image point on pixel values and texture features of Finnish forest plots in digitised CIR photographs the clearest differences were found between front-and back-lighted image halves. Inside the image half the differences between different blocks were clearly bigger on the front-lighted half than on the back-lighted half. The strength of the phenomenon varied by forest category. The differences between pixel values extracted from different image blocks were greatest in developed and mature stands and smallest in young stands. The differences between texture features were greatest in developing stands and smallest in young and mature stands. The logarithm of timber volume per hectare and the angular transformation of the proportion of broadleaved trees of the total volume were used as dependent variables in regression models. Five different converted image co-ordinates based trend surfaces were used in models in order to diminish the effect of the bidirectional reflectance. The reference model of total volume, in which the location of the image point had been ignored, resulted in RMSE of 1,268 calculated from test material. The best of the trend surfaces was the complete third order surface, which resulted in RMSE of 1,107. The reference model of the proportion of broadleaved trees resulted in RMSE of 0,4292 and the second order trend surface was the best, resulting in RMSE of 0,4270. The trend surface method is applicable, but it has to be applied by forest category and by variable. The usefulness of multi-image interpretation of digitised aerial photographs was studied by building comparable regression models using either the front-lighted image features, back-lighted image features or both. The two-image model turned out to be slightly better than the one-image models in total volume estimation. The best one-image model resulted in RMSE of 1,098 and the two-image model resulted in RMSE of 1,090. The homologous features did not improve the models of the proportion of broadleaved trees. The overall result gives motivation for further research of multi-image interpretation. The focus may be improving regression estimation and feature selection or examination of stratification used in two-phase sampling inventory techniques. Keywords: forest inventory, digitised aerial photograph, bidirectional reflectance, converted image co­ordinates, regression estimation, multi-image interpretation, pixel value, texture, trend surface

Remote sensing of boreal land cover: estimation of forest attributes and extent

Remote sensing provides methods to infer land cover information over large geographical areas at a variety of spatial and temporal resolutions. Land cover is input data for a range of environmental models and information on land cover dynamics is required for monitoring the implications of global change. Such data are also essential in support of environmental management and policymaking. Boreal forests are a key component of the global climate and a major sink of carbon. The northern latitudes are expected to experience a disproportionate and rapid warming, which can have a major impact on vegetation at forest limits. This thesis examines the use of optical remote sensing for estimating aboveground biomass, leaf area index (LAI), tree cover and tree height in the boreal forests and tundra taiga transition zone in Finland. The continuous fields of forest attributes are required, for example, to improve the mapping of forest extent. The thesis focus on studying the feasibility of satellite data at multiple spatial resolutions, assessing the potential of multispectral, -angular and -temporal information, and provides regional evaluation for global land cover data. Preprocessed ASTER, MISR and MODIS products are the principal satellite data. The reference data consist of field measurements, forest inventory data and fine resolution land cover maps. Fine resolution studies demonstrate how statistical relationships between biomass and satellite data are relatively strong in single species and low biomass mountain birch forests in comparison to higher biomass coniferous stands. The combination of forest stand data and fine resolution ASTER images provides a method for biomass estimation using medium resolution MODIS data. The multiangular data improve the accuracy of land cover mapping in the sparsely forested tundra taiga transition zone, particularly in mires. Similarly, multitemporal data improve the accuracy of coarse resolution tree cover estimates in comparison to single date data. Furthermore, the peak of the growing season is not necessarily the optimal time for land cover mapping in the northern boreal regions. The evaluated coarse resolution land cover data sets have considerable shortcomings in northernmost Finland and should be used with caution in similar regions. The quantitative reference data and upscaling methods for integrating multiresolution data are required for calibration of statistical models and evaluation of land cover data sets. The preprocessed image products have potential for wider use as they can considerably reduce the time and effort used for data processing.

Parisuhdetyössä toimivien vapaaehtoisten motivaatio ja sitoutuminen : Tutkimus HNMKY:n parisuhderyhmien ryhmänjohtajista

Tutkimuksen tarkoituksena on tarkastella kristillisessä parisuhdetyössä toimivien, HNMKY:n vapaaehtoisten ryhmänjohtajien motivaatiota ja sitoutumista sekä näiden välistä yhteyttä. Tutkimuksessa selvitettiin, keitä HNMKY:n avioliittoleirin vapaaehtoiset ryhmänjohtajat ovat, mitkä ovat heidän motivaatiot ryhmänvetäjinä sekä, mihin he ovat sitoutuneet ja, mikä heitä sitouttaa. Tutkimuksessa tarkasteltiin erityisesti arvoihin ja organisaatioon sitoutumista. Tutkimuksen empiirinen aineisto koostui Paremman avioliiton perheleirien 2007 ja 2008 vapaaehtoisien parisuhderyhmien ryhmänjohtajina toimineilta kerätystä kyselyaineistosta (N=163). Tutkimusote oli kvantitatiivinen. Teoreettinen viitekehys muodostui motiivien osalta Claryn ja kumppaneiden kehittelemästä The Volunteer Functions Inventory -mallista (VFI), joka on kehitetty vapaaehtoisten motiivien mittaamiseen sekä muusta aiemmasta motiivitutkimuksesta. Sitoutumisen osalta teoreettinen viitekehys muodostui vapaaehtoisten sitoutumiseen liittyvästä teoriasta sekä aiemmasta sitoutumisen tutkimuksesta. Parisuhdetyön ryhmänvetäjiltä löydettiin faktorianalyyseilla aiemmasta tutkimuksesta osittain poiketen neljä erilaista motivaatiota: 1) Oman parisuhteen hoito, 2) Auttamisen arvot, 3) Itselle saaminen sekä 4) Toimiminen yhdessä. Merkittävin vapaaehtoisuuteen motivoiva tekijä oli Oman parisuhteen hoito, joka sisälsi oman parisuhteen hoidon lisäksi omien vaikeuksien käsittelyä sekä vertaistukeen liittyviä motivaatioita. Auttamisen arvot sisälsivät toisten auttamisen tärkeyden sekä kristilliset arvot. Itselle saaminen piti sisällä oppimismotiiveja sekä omat vaikeudet motiiveja. Toimiminen yhdessä käsittää itsetuntomotiiveja ja sosiaalisia motiiveja. Näistä Itselle saaminen ja Toimiminen yhdessä liittyivät merkittävästi toisiinsa. Ryhmänvetäjiltä löydettiin faktorianalyyseilla neljä erilaista sitotuttavaa tekijää: 1) Saatu tuki, 2) Osa identiteettiä, 3) Palkitsevuus sekä 4) Onnistuminen auttamisessa. Merkittävin syy vapaaehtoisuuteen sitoutumiseen on Saatu tuki, joka sisältää sekä HNMKY:ltä että myös muilta ryhmänjohtajilta saadun tuen. Osa identiteettiä sisältää sen, että ryhmänjohtamisesta on tullut osa minua, ja että toiminta on vahvistanut itsetuntoa sekä sopii elämäntilanteeseen. Tähän sisältyi myös toisten auttamisen tärkeys. Sitouttavista tekijöistä vahvimmin toisiinsa liittyvät Saatu tuki ja Osa identiteettiä. Motivaatio ja sitoutuminen liittyvät monella tavoin toisiinsa. Merkittävimmin toisiinsa liittyvät motivaatiossa Auttamisen arvot ja sitoutumisessa Osa identiteettiä. Näille ihmisille auttamisen arvoissa tärkeää ovat kristillisten arvojen edistäminen parisuhdetyössä sekä merkittävien asioiden tekeminen itselle tärkeässä tehtävässä. Heitä motivoi toisten auttaminen ja sama asia sitouttaa heitä myös vapaaehtoiseen parisuhdetyöhön. Niitä ryhmänjohtajia, joita motivoi vapaaehtoistoimintaan oma parisuhteen hoito, sitouttaa tähän työhön sen palkitsevuus. Niitä, joita motivoivat Auttamisen arvot tai Itselle saaminen, sitouttaa Saatu tuki, Osa identiteettiä ja Palkitsevuus. Kun motivoivana tekijänä on Toiminen yhdessä, silloin sitouttaa Saatu tuki ja Osa identiteettiä. Ryhmänjohtajat ovat erittäin sitoutuneita HNMKY:n arvoihin ja opetukseen. Vastaajille on erittäin merkittävää kristillisten arvojen edistäminen parisuhdetyössä. Kristillisyyden ja sen arvojen merkityksellisyys, auttamisen sekä oman parisuhteen ja perheen tärkeys liittyvät toisiinsa. Avainsanat – Nyckelord Vapaaehtoistyö, motiivit, sitoutuminen, parisuhde Säilytyspaikka – Förvaringställe Teologisen tiedekunnan kirjasto

Ett' varttuisi Suomenmaa : Suomalaisten kasvattaminen kulutusyhteiskuntaan kotimaisissa lyhytelokuvissa 1920-1969

The birth of the Modern Consumer Society in Finnish short films 1920-1969 The main subject of this research is Finnish short films in 1920-1969. These short films were produced by film studios for private enterprises, banks, advisory organizations, communities and the state. The evolution of short films on consumer affairs was greatly influenced by a special tax reduction system that was introduced in 1933 and lasted until 1964. The tax reduction system increased the production volumes of educational short films significantly. This study covers 342 Finnish short films, more than any other study in the field before this. The aim of this research is to examine how short films introduced Finns to modern consumer society. The cinemagoers were an excellent target group for different advisory groups as well as advertisers. Short films were used by organizations and private enterprises from very early on. In the 1920's Finns were still living in rural areas and agriculture was the dominant industry. Consumer society was still in its infancy, and the prevalent attitude to industrially produced goods was that of suspicion. From the cultural and ideological point of view the evolution of trust was one of the first steps towards the birth of the consumer society. Short films were an excellent means for helping to transform public attitudes. During the war period short films were an important means of propaganda. Short films were produced in abundance and shown for big audiences. They guided people how to survive shortages caused by the war. Even though the idea of rationalization was presented in short films somewhat in the 1920's and 1930's it became a national virtue during the war period. The idea of rationalization widened from the industry to households expecially in the late 1940's and the 1950's. New household apparati and the way in which daily chores were taken care of were presented not as luxury consumption but as a way of rationalization and saving money and effort. Banks and the advisory organizations guided the public to save their money for a specific target. Short films were use to help the public to acceps industrial goods and the notions of planning and saving. The ideological change from an agrarian society to consumer society was based on old acricultural ideas and self-sufficiency was evolved into rational and economizing consumerism. This made Finnish consumer society to value durable consumer goods and own homes. The public was also encouraged to consider their own decisions in the national context - especially after the second world war Finland laced capital, and personal savings were strongly presented as a way to help the whole nation. Modern hedonistic values were not dominant in Finland in the1950's and 1960's. Initial traces of modern hedonism can be seen in the films, but they were only marginal paths in the bigger.

Country-scale carbon accounting of the vegetation and mineral soils of Finland

The increase in global temperature has been attributed to increased atmospheric concentrations of greenhouse gases (GHG), mainly that of CO2. The threat of severe and complex socio-economic and ecological implications of climate change have initiated an international process that aims to reduce emissions, to increase C sinks, and to protect existing C reservoirs. The famous Kyoto protocol is an offspring of this process. The Kyoto protocol and its accords state that signatory countries need to monitor their forest C pools, and to follow the guidelines set by the IPCC in the preparation, reporting and quality assessment of the C pool change estimates. The aims of this thesis were i) to estimate the changes in carbon stocks vegetation and soil in the forests in Finnish forests from 1922 to 2004, ii) to evaluate the applied methodology by using empirical data, iii) to assess the reliability of the estimates by means of uncertainty analysis, iv) to assess the effect of forest C sinks on the reliability of the entire national GHG inventory, and finally, v) to present an application of model-based stratification to a large-scale sampling design of soil C stock changes. The applied methodology builds on the forest inventory measured data (or modelled stand data), and uses statistical modelling to predict biomasses and litter productions, as well as a dynamic soil C model to predict the decomposition of litter. The mean vegetation C sink of Finnish forests from 1922 to 2004 was 3.3 Tg C a-1, and in soil was 0.7 Tg C a-1. Soil is slowly accumulating C as a consequence of increased growing stock and unsaturated soil C stocks in relation to current detritus input to soil that is higher than in the beginning of the period. Annual estimates of vegetation and soil C stock changes fluctuated considerably during the period, were frequently opposite (e.g. vegetation was a sink but soil was a source). The inclusion of vegetation sinks into the national GHG inventory of 2003 increased its uncertainty from between -4% and 9% to ± 19% (95% CI), and further inclusion of upland mineral soils increased it to ± 24%. The uncertainties of annual sinks can be reduced most efficiently by concentrating on the quality of the model input data. Despite the decreased precision of the national GHG inventory, the inclusion of uncertain sinks improves its accuracy due to the larger sectoral coverage of the inventory. If the national soil sink estimates were prepared by repeated soil sampling of model-stratified sample plots, the uncertainties would be accounted for in the stratum formation and sample allocation. Otherwise, the increases of sampling efficiency by stratification remain smaller. The highly variable and frequently opposite annual changes in ecosystem C pools imply the importance of full ecosystem C accounting. If forest C sink estimates will be used in practice average sink estimates seem a more reasonable basis than the annual estimates. This is due to the fact that annual forest sinks vary considerably and annual estimates are uncertain, and they have severe consequences for the reliability of the total national GHG balance. The estimation of average sinks should still be based on annual or even more frequent data due to the non-linear decomposition process that is influenced by the annual climate. The methodology used in this study to predict forest C sinks can be transferred to other countries with some modifications. The ultimate verification of sink estimates should be based on comparison to empirical data, in which case the model-based stratification presented in this study can serve to improve the efficiency of the sampling design.

Export of organic matter, sulphate and base cations from boreal headwater catchments downstream to the coast: impacts of land use and climate

The terrestrial export of dissolved organic matter (DOM) is associated with climate, vegetation and land use, and thus is under the influence of climatic variability and human interference with terrestrial ecosystems, their soils and hydrological cycles. The present study provides an assessment of spatial variation of DOM concentrations and export, and interactions between DOM, catchment characteristics, land use and climatic factors in boreal catchments. The influence of catchment characteristics, land use and climatic drivers on the concentrations and export of total organic carbon (TOC), total organic nitrogen (TON) and dissolved organic phosphorus (DOP) was estimated using stream water quality, forest inventory and climatic data from 42 Finnish pristine forested headwater catchments, and water quality monitoring, GIS land use, forest inventory and climatic data from the 36 main Finnish rivers (and their sub-catchments) flowing to the Baltic Sea. Moreover, the export of DOM in relation to land use along a European climatic gradient was studied using river water quality and land use data from four European areas. Additionally, the role of organic and minerogenic acidity in controlling pH levels in Finnish rivers and pristine streams was studied by measuring organic anion, sulphate (SO4) and base cation (Ca, Mg, K and Na) concentrations. In all study catchments, TOC was a major fraction of DOM, with much lower proportions of TON and DOP. Moreover, most of TOC and TON was in a dissolved form. The correlation between TOC and TON concentrations was strong and TOC concentrations explained 78% of the variation in TON concentrations in pristine headwater streams. In a subgroup of 20 headwater catchments with similar climatic conditions and low N deposition in eastern Finland, the proportion of peatlands in the catchment and the proportion of Norway spruce (Picea abies Karsten) of the tree stand had the strongest correlation with the TOC and TON concentrations and export. In Finnish river basins, TOC export increased with the increasing proportion of peatland in the catchment, whereas TON export increased with increasing extent of agricultural land. The highest DOP concentrations and export were recorded in river basins with a high extent of agricultural land and urban areas, reflecting the influence of human impact on DOP loads. However, the most important predictor for TOC, TON and DOP export in Finnish rivers was the proportion of upstream lakes in the catchment. The higher the upstream lake percentage, the lower the export indicating organic matter retention in lakes. Molar TOC:TON ratio decreased from headwater catchments covered by forests and peatlands to the large river basins with mixed land use, emphasising the effect of the land use gradient on the stoichiometry of rivers. This study also demonstrated that the land use of the catchments is related to both organic and minerogenic acidity in rivers and pristine headwater streams. Organic anion dominated in rivers and streams situated in northern Finland, reflecting the higher extent of peatlands in these areas, whereas SO4 dominated in southern Finland and on western coastal areas, where the extent of fertile areas, agricultural land, urban areas, acid sulphate soils, and sulphate deposition is highest. High TOC concentrations decreased pH values in the stream and river water, whereas no correlation between SO4 concentrations and pH was observed. This underlines the importance of organic acids in controlling pH levels in Finnish pristine headwater streams and main rivers. High SO4 concentrations were associated with high base cation concentrations and fertile areas, which buffered the effects of SO4 on pH.

Carabid beetles (Coleoptera, Carabidae) as indicators of environmental change in Ranomafana National Park, Madagascar

Growing human populations and increasing exploitation of natural resources threaten nature all over the world. Tropical countries are especially vulnerable to human impact because of the high number of species, most of these endemic and still unknown. Madagascar is one of the centers of high biodiversity and renowned for its unique species. However, during the last centuries many endemic species have gone extinct and more are endangered. Because of high natural values, Madagascar is one of the global conservation priorities. The establishment of Ranomafana National Park (RNP) was intended to preserve the unique nature of Madagascar. Containing several endemic and threatened species, Ranomafana has been selected as one of UNESCO’s World Natural Heritage sites. However, due to strong human pressures the region immediately surroundings the protected area has severely degraded. Aims of this thesis were to inventory carabid fauna in RNP and evaluate their use as indicators of the environmental change. Carabid beetles were collected from protected area (secondary and primary forests) and from its degraded surrounding area. Collecting was mostly conducted by hand during years 2000-2005. Species compositions between the protected area and its surroundings were compared, and species habitat preferences and seasonal variations were studied. In total, 4498 individuals representing 127 carabid species (of which 38 are new species) were collected. Species compositions within and outside of the protected area were markedly different. Most of the species preferred forest as their primary habitat and were mainly collected from trees and bushes. Their value as indicators is based on their different habitat requirements and sensitivity to environmental variables. Some of the species were found only in the protected forest, some occupied also the degraded forests and some preferred open areas. Carabid fauna is very species rich in Ranomafana and there are still many species to be found. Most of the species are arboreal and probably cannot survive in the deforested areas outside the park. This is very likely also the case for other species. Establishment and continued protection of RNP is probably the only way to conserve this globally important area. However, new occupations and land use methods are urgently needed by the local people for improving their own lives while maintaining the forest intact.

Reproduction and population structure in European aspen

The European aspen (Populus tremula) is a keystone species for biodiversity in boreal forests. However, the future of aspen may be threatened, because large aspens have mostly been removed from managed forests, whereas regeneration and the long-term persistence of mature trees are subjects of concern in protected areas. Aspen is a pioneer tree, and it can reproduce both sexually by seed and asexually by root suckers. Through asexual reproduction aspen forms clones, groups of genetically identical trees (ramets). In my thesis, I have studied the structure of aspen populations in terms of number, size, clonal and demographic properties. Additionally, I have investigated the emergence and survival of seedlings as well as the seed quantity and quality in crosses between the European and hybrid aspen. To study the regeneration and population structure, mature aspens were recorded in old-growth and managed forests in eastern Finland based on a large-scale inventory (11 400 ha). In addition, small aspen trees were surveyed on sample plots. Clonal structure was investigated both by morphological characters and by DNA-based markers (microsatellites). Seedling emergence and survival was studied with two sowing experiments. With crosses between European and hybrid aspens we wanted to study whether elevated temperatures due to climate change would benefit the different crosses of European and hybrid aspen unequally and thus affect the gene flow between the two species. The average volumes of mature aspen were 5.3 m3/ha in continuous old-growth, and 0.8 m3/ha in managed forests. Results indicate also that large aspen trees in managed forests are a legacy of the past less intensively managed forest landscapes. Long-term persistence of aspen in protected areas can only be secured by restoration measures creating sufficiently large gaps for regeneration. More emphasis should be given to sparing aspens in thinnings and to retaining of mature aspens in regeneration cutting in managed forests. Aspen was found to be spatially aggregated in the landscape. This could be explained by site type, disturbance history and / or limitations in seed dispersal. Clonal structure does not explain the spatial aggregation, since average size of the clones was only 2.3 ramets, and most clones (70 %) consisted of just one ramet. The small size of the clones suggests that most of them are relatively young. Therefore, sexual reproduction may be more common than has previously been thought. Seedling emergence was most successful in mineral soil especially, when the site had been burned. Only few seedlings occurred on humus. Survival of the seedlings was low, and strongly dependent on moisture, but also on seedbed conditions. The seeds were found to maintain their germinability longer than has earlier been thought to be possible. Interspecific crosses produced more seeds with higher quality than intraspecific crosses. When temperature was elevated, germination of hybrid aspen seeds increased more than seeds from P. tremula x P. tremula crosses. These results suggest that hybrid aspen may have a significant genetic impact on the European aspen, and this effect may become strengthened by climate warming.