Canada has 418 million hectares of forests, representing 10% of the forested land in the world [I]. In 1997, Canada signed the Kyoto Protocol and agreed to cut greenhouse gas emissions by six percent below the 1990 level between 2008 and 2012 [2]. This agreement was ratified in December 2002. It requires Canada to report Canada's sustainable forest resources, including information about forest carbon, afforestation, reforestation, and deforestation (ARD). To fulfill this commitment, effective and accurate measuring tools are needed. One of these tools is satellite remote sensing, a cost-effective way to examine large forested areas in Canada for timely forest information. Historically, the study of forest aboveground carbon was carried out with detailed forest inventory and field sampling from temporary and permanent sample plots, which severely limited the forest area that could be studied. For regional and global scales, it is necessary to use remote sensing for aboveground carbon and ARD mapping due to time and financial constraints. Therefore, the purpose of this research is to develop, implement, and evaluate a computing system that uses multitemporal Landsat satellite images [3] to estimate the Kyoto-Protocol-related forest parameters and create geo-referenced maps, showing the spatial distribution of these parameters in a Geographic Information System (GIs). The new computing system consists of a segment-based and supervised classification engine with feature selection functionality and a Kyoto-Protocol-products estimation unit. The inclusion of the feature selection reduces the large dimensionality of the feature space of multitemporal remote Landsat data sets. Thus, more images could be added into the data sets for analysis. The implementation of the segment-based classifiers provides more accurate forest cover classifications for estimating the Kyoto Protocol products than pixel-based classifiers. It is expected that this approach will be a new addition to the current existing methodologies for supporting Canada's reporting commitments on the sustainability of the forest resources in Canada. This approach can also be used by other countries to monitor Canada's compliance with international agreements.

This research involved three years of field work in Glen Tanar, NNR, in northeast of Scotland. The role and seedbed preparation on regeneration of native pinewood and birchwood has been studied. The ground disturbance effects on soil seed bank, soil nutrient dynamics and ground vegetation recovery have been investigated in detail. Effect of light and burning of soil or fertiliser on Scots pine and silver birch seedling survival and growth were monitored in the laboratory to provide some information for the field observations. Germination of pine and birch seeds began about 3 weeks after experimental sowing at the end of July, 1988. However, the number of germinants in 1989 and 1990 was much lower than in 1988. 90% of Scots pine viable seeds died or failed to germinate and more than 95% of birch viable seeds failed to germinate. The germination of pine and birch seedlings was greatly increased when the moss and litter layers were completely removed by the `Burning' and `Pull' treatments. With treatments in which no humus was removed, the treatments `Control' and `Cut', little or no germination of pine and birch seeds occurred. Mortality of both pine and birch seedlings established in 1988 is significantly less on all sub-plots of ground treatments than seedlings established in 1989. Seedlings which were established after light burning are suffering the highest mortality in most cases, possibly because of competition from unburnt <i>Calluna</i> shoots and the rapid recovery of the ground flora in this treatment. Birch seedlings established in 1989 are suffering higher mortalities than pine seedlings established in 1989 on most of the ground treatments. Scots pine and birch seedlings were significantly depressed in relation to increasing shade in terms of height growth, biomass production and relative growth rates, which might suggest that birch and pine are both shade-avoider and light-demanding species. Scots pine seedlings demonstrate a much lower compensation point (3% RLI, relative light intensity) than birch (12% RLI) seedlings. Scots pine would thus have better survival than birch under shaded conditions of 10% RLI or less. The laboratory experiment showed that birch and pine seedling height growth was enhanced by burning or PK fertiliser treatments. Burning plus PK fertiliser is better than burning alone. Growth of Scots pine and silver birch seedlings in the absence of PK fertiliser additions was enhanced by burning but not by ash additions. Seedling height, relative growth rate, biomass and nutrient assimilation were greater on burned soil. Birch seedling demonstrates higher growth rate, higher height growth and more sensitive response to burning or fertiliser addition than pine seedling. However, the field study showed that height growth of pine and birch was not significantly increased by burning. The field enumeration surveys at Glen Tanar showed that some forms of soil disturbance (mechanical or burning) might be necessary and beneficial to Scots pine and birch regeneration. However, in the longer term, fencing (or some forms of protection from browsing) is very important to secure tree regeneration since the significant effect of initial soil disturbance was eliminated 12 years after the disturbance.

Deforestation problem at a global level in general and in developing countries in particular have been an issue of prime concern among researchers and both government and non government organisations all over the world. Its causes have been identified as the daily demand of people for fuelwood, fodder and small timber in rural areas of developing countries in general and India in particular. This led to the emergence of a new concept of social forestry with agroforestry or farm-level tree growing as its integral part in the late 1970's. The programmes and projects on both social forestry and agroforestry in India have been dealt with in a 'top-down' approach to planning. Perhaps that it why they have not achieved the desired success. The reverse approach or 'bottom-up' approach because of its time and resource consuming nature, has not been adopted by the Government. Therefore, 'microplanning' a compromise approach, has been suggested in the present study. As individual households are at the lowest level of the microplanning system, household level linear programming models have been developed in this study. The models have been developed and tested on a field survey of three villages in the Haryana state in India. The study has demonstrated that tree planting on farms can increase farm income and can play a significant role in rural development in India. The models developed in this study can be used to estimate farm incomes following the introduction of trees on farms such that the most economically viable option can be recommended to each farmer. The validation of these models confirms the potential for farm level tree growing in Haryana.

This thesis has the aim of presenting a forest management system to be applied on small farms, especially in the settlement projects of the Brazilian Amazon, and to examine its sustainability by investigating the responses of the forest in terms of the changes in natural regeneration in felling gaps and the dynamics of the residual trees. Using the program CAFOGROM, an additional aim was to simulate the forest responses to different cycle lengths, harvesting intensities and silvicultural treatments to determine the theoretical optimum combination of these parameters. The proposed forest management system was designed to generate a new source of family income and to maintain the structure and biodiversity of the legal forest reserves. The system is new in three main characteristics: the use of short cycles in the management of tropical forest, the low harvesting intensity and environmental impact and the direct involvement of the local population in all forest management activities. It is based on a minimum felling cycle of ten years and an annual harvest of 5-10 m3 ha-1 of timber. The gaps produced by logging in PC Peixoto can be classified as small or less often medium sized (canopy openness from 10% to 25%). Differences in gap size and canopy openness produced significant differences in the growth rates, species richness and species diversity of seedlings, but no statistically significant differences could be determined according to the position of the quadrats in the gaps. Mortality rates increased and recruitment rates decreased with increasing gap size. The density and recruitment of seedlings of commercial species was not different between gap sizes, but gap creation increased the growth rate of the seedlings of these species.

Seed production and germination of some timber tree species were studied in Ghana for possible prediction of seed yield and natural regeneration. Seed phenology in 13 species was monitored for two years, using permanent seed traps in two forest sites. Seed germination tests were conducted in neutral, green shade and dark in shade houses for 20 species. In the forest, germination was tested in forest gaps receiving different irradiances. Fruiting frequency ranged from twice in each year to supra-annual fruiting. Fruiting periods for species were consistent between years. Fruiting synchrony was higher among individuals of a population than between sites for the same species. Fecundity differed between years for the majority of species and between sites for species common to both sites. Premature fruit abscission was quite common. Maximum seed weight and percentage germination occurred during peak fall of mature seeds. Seeds of the majority of species germinated equally in light and dark and also in neutral and low red: far red ratio. These included some species previously classified as pioneers. In the forest germination was depressed in a large clearing for the majority of species. The use of photoblastic germination alone to define pioneers leads to a smaller group of pioneer species than is presently recognised. Large gaps due to logging may discourage natural regeneration.

A study was carried out to investigate the effect of four tree species on the acidity and chemistry of rainwater as it passed down the forest profile. The four species, Norway spruce (Picea abies), Scots pine (Pinus sylvestris), oak (Quercus petraea) and alder (Alnus glutinosa) were all at the same site at Gisburn (Bowland Forest), north-west England. The water was collected as rain, beneath the canopy and the forest floor, at the boundary of the A and B horizons and within the B horizon. The water was collected and analysed for pH, PO43--P, NO3--N, NH4+-N, Cl, SO42--S, Na+, Ca2+ and Mg2+ every two weeks. There were occasional analyses for aluminium. Porous ceramic cups were used to collect water in the soil horizons and so volumes had to be estimated. A further correction had to be made to allow for the loss of water as runoff over the surface of the forest floor. There were consistent differences between the species. The species differed in both the processes responsible for and the location of the production of acidity. Under all species there was a great reduction in acidity in the deep soil horizons. The source and nature of the anion thought to be associated with cation leaching also differed under the species. Most of the species differences could be attributed to processes occurring in the forest floor. Of most importance were: the fixation of atmospheric nitrogen by alder and its subsequent release as NO3--N; the rate of decomposition of the various litters; and the horizon where most root uptake occurred. The differences observed in the throughfall were not reflected in the forest floor or soil horizons. There was no evidence of depletion of cations in the mineral soils after thirty years of tree growth but it was considered that the risk was greater under alder and pine than under spruce and least under oak.

Sitka spruce from three upland sites in Scotland was studied in order to discover how growth rate and quality was affected by site and management. Two of the sites, established in the late 60s, contained nursed and fertilised treatments so spruce in intimate mixture with lodgepole pine and larch could be compared with spruce which had been annually or periodically fertilised with N. Spruce (P46) from the third site had been planted in row mixture with Scots pine on three different types of cultivation. A detailed analysis of growth rates in diameter, height and volume was carried out. Crown form and the dependent characteristics - branchiness, stem taper and ellipticity - were compared between treatments. Wood quality was assessed through density, knot content and the proportions of juvenile and compression wood. It was clear that nursing was an effective means of raising a crop of Sitka spruce, even on a deep peat site, but that lodgepole pine was most likely to reduce branchiness, taper and ellipticity and therefore would promote the growth of better quality timber. Repeated applications of N did not encourage volume production but rather immoderate branching and poor stem form. On the older site complete ploughing had increased growth rates during the first 20 years but in the long term there was no gain. Analysis of horizontal and vertical trends in density showed that spruce from all sites were producing timber of desirable strength properties but that the presence of knots, compression wood and, in some treatments, the extent of the juvenile core greatly reduced timber quality. A survey was carried out to test the use of the pilodyn to estimate density and the results were encouraging.

Acid soil infertility has been associated with excess of Al, either Mn toxicity or deficiency, deficiencies or toxicities of one or more other trace elements, or deficiencies of certain major nutrients such as Ca, Mg, P and K. Studies on the influences of these factors on the tree growth are useful in identifying the mechanisms and the genetic sources of tolerance to acid soil. A series of five culture experiments, under controlled conditions, were carried out using Greek and British Scots (Pinus sylvestris L.) seedlings as well as black pine seedlings of Greek (Pinus nigra Arnold var. nigricans Host) and 'British' (Pinus nigra var. maritima (Ait.) Melville) origin. Nine major and trace elements (N, P, K, Ca, Mg, Fe, Mn, Zn and Cu) were determined in the growth components of pine seedlings. The Mn and Ca requirements of the pine seedlings of all growth components were assessed. Foliar values found for the Mn (ppm) and Ca (%) concentrations associated with 90% of maximum yield were: a) Greek-derived Scots pine: Mn 84-855 and Ca 0.34-1.00, b) British-derived Scots pine: Mn 77-1,450 and Ca 0.43-0.87, c) Austrian pine: Mn *-2,100 and Ca 0.27-*, and d) Corsican pine: Mn *-1,400 and Ca 0.30-0.73 (* denotes not estimated). The results suggested that under conditions of low Ca availability, excessive Mn uptake could result in toxicity in Greek pines and the feed solution Ca/Mn concentration ratio is an important factor in determining the ability of British pines to tolerate adverse Mn conditions. The relative tolerance of Corsican pine to Mn toxicity is related both to immobilisation of Mn in roots by increased Ca uptake, particularly at low solution Ca availability, and to inhibition of Mn translocation from roots to the foliage, while that of British P.sylvestris is associated to its ability to withstand high Mn concentration in shoots. The characteristic nutritional behaviour of Corsican pine (exclusion of some essential elements from the foliage) appeared to be partly responsible for the induced Mg and Fe deficiencies by excess Mn availability. Furthermore, the adverse influence of increasing solution Mn availability on Ca concentration of pine seedlings is dependent on the availability of Ca in the nutrient solution, on the component part analysed, on the genotype and on the experimental conditions. The presence of two absorption mechanisms for Mn and a close functional relationship between Ca and Mn in foliage of seedlings is suggested.

Investigations have been carried out into the effects of nitrate and ammonium on: the growth dynamics of mycor-rhizal fungi, the relative infection success of these fungi when associated with Douglas-fir and Sitka spruce seedlings, and the growth and nitrogen uptake by mycorrhizal and non-mycorrhizal seedlings. Fungal isolates were obtained from sporocarps collected in Douglas-fir or Sitka spruce stands. On the basis of growth rate and nitrogen utilisation patterns, Paxillus involutus and Lactarius rufus were chosen for further study. Both fungi were capable of rapid growth; but while P. involutus grew equally well when either ammonium or nitrate was supplied, L. rufus could only utilise ammonium. In aseptic culture with seedlings of Douglas-fir or Sitka spruce, both fungi readily formed ectotrophic mycorrhizas. These experiments were carried out in Erlenmeyer flasks. Although pure cultures of P. involutus grew well when either nitrate or ammonium was the nitrogen source, those supplied ammonium were always the heaviest. However, when the calculated energy cost of nitrate reduction was deducted from the ammonium cultures, the weights of nitrate and ammonium cultures became nearly identical. Furthermore, nitrogen form had no effect on the growth rate of P. involutus cultures. When the quantity of glucose supplied was increased from 0.5 g/1-1 to 2.0 g/1-1 , the culture weight increased proportionally, but increasing the glucose to 4.0 g/1-1 brought about a less than proportional weight gain. Regardless of original nitrogen form, or amount of glucose supplied, whenever P. involutus cultures entered the senescent phase of growth ammonium was released into the nutrient solution. In pure culture L. rufus grew well when ammonium was supplied, but was completely unable to utilise nitrate. Increasing the amount of glucose supplied brought about less than proportional increases in the weight of the colony, with the least glucose producing the greatest relative weight. Lactarius rufus never released nitrogen during the senescent phase of growth. The three previously mentioned mycorrhizal conditions (inoculated with P. involutus or L. rufus, or uninoculated) were factorially combined with nitrate and ammonium in a series of experiments that used Douglas-fir and Sitka spruce seedlings. Unlike the initial synthesis testing, these experiments used an improved culture unit that allowed the frequent replenishment of water and nutrient supplies. Sitka spruce was used in the first experiment. As expected the P. involutus/ammonium and the L. rufus/ammonium treatments formed abundant mycorrhizas (72.3% and 70.5% respectively). In contrast when nitrate was the nitrogen source, L. rufus formed no mycorrhizas and P. involutus infected only 6.4% of the short roots. Plants supplied ammonium produced more dry matter than those given nitrate, with the uninoculated plants being larger than either of the mycor-rhizal treatments. In the second experiment, the amount of nutrient was reduced by 80% and Douglas-fir seedlings were used. The same general patterns of growth and mycor-rhiza infection seen in the first experiment were repeated. Leaks in the culture units used in the first two experiments made the nitrogen uptake data unusable. In the third experiment, Sitka spruce seedlings were grown with the same reduced amount of nutrient as the plants in the second experiment. The same pattern of mycorrhizal infection was repeated, but unlike the other experiments the various treatments within the ammonium treatment were not statistically different. Although nitrogen uptake was similar among the different treatments within the nitrate group, mycorrhizal infection increased ammonium uptake. This increase resulted in a higher nitrogen content in the roots. The exact role of nitrate in the disruption of mycorrhizas was examined by alternating from ammonium to nitrate (and vice versa) and by adding root exudates and macerates to pure cultures of P. involutus and L. rufus. When the nitrogen supply was changed from nitrate to ammonium, the rate of formation of P. involutus mycorrhizas was apparently increased. However, when the nitrogen supply was changed from ammonium to nitrate the mycorrhizas already formed became unstable. In the case of the L. rufus and ammonium then nitrate treatment, the metabolism of the entire plant was apparently effected by the nitrogen form change. In contrast to work by others, the exudates and macerates did not stimulate or retard the growth of L. rufus or P. involutus.

Aspects of natural regeneration were studied in the native Scots pinewood of Glentanar near Aboyne in Aberdeenshire during 1978 and 1979. Quantities of seed produced, the time and distance of seed dispersal, and germination capacity and energy of the seed, were assessed in the laboratory and the forest. In characteristics of different seed beds litter, mineral soil, humus and mixtures of these were examined and mixtures of humus and mineral soil were most favourable to seed germination and early survival of seedlings. The group shelterwood system of germination was compared with uniform shelterwood. The former appeared more favourable to Scots pine regeneration at Glentanar.