Thesis (doctoral)--Radboud Universiteit, Nijmegen, 2008. / Description based on print version record. Includes bibliographical references (p. [183]-188).

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Thesis (Ph.D.) -- McMaster University, 2002. / Includes bibliographical references. Also available via World Wide Web.

Thesis (doctoral)--Radboud Universiteit, Nijmegen, 2008. / Includes bibliographical references (p. [183]-188).

Succession following shifting cultivation was studied in secondary forests (5 to 40 years old) and a primary forest in Bragantina region, Para, Brazil. Secondary forests covered 62% of the study area (89 km² ) and crops and pasture 18%. Soil analyses showed an increase in pH, exchangeable calcium, magnesium and potassium and a decrease of organic matter and exchangeable aluminium, immediately after burning. Organic matter and extractable phosphorus increased with forest age, exchangeable aluminium and potassium were the same in both secondary and primary forests and exchangeable calcium and magnesium remained higher in the secondary forests. The highest densities of individuals and the least basal area and height were found in the younger secondary forests. The number of woody species (≥5 cm dbh) 250-m2 plot ranged from 8 to 17 in the secondary forests and 17 to 27 in the primary forest. Ordination and classification of floristic data suggested four successional communities. The forests regenerated readily and studies showed: the largest seed bank (0-5 cm) in the 5-years-old forest (1190 ± 284 seeds m-2) and a decrease with age to 137 ±19 seeds m-2 in the primary forest; the highest seed rain in the 5-years-old forest (883 ± 230 seeds m-2) and least in the primary forest (220 ± 80); 46% of the smaller plants (≥1 m tall, < 5 cm dbh) were seedlings and 54% were sprouts in the 5-years-old forest but in the 10-years and 20-years-old forests, seedlings (81%) predominated; adult plants (≥5 cm db h) in 5 to 20-years-old plots regenerated mainly from sprouts. Even after about 90 years of shifting cultivation the region has the potential for forest regeneration and the soil nutrients are able to recover to values similar to those in the primary forest. This raises the hope that, if a land use plan for Bragantina could be implemented, then it would be successful.

Generally it is not adequate to calculate an allowable cut for a property by only one formula or method. Usually it is preferable to utilize all the information available with as many suitable formulae or methods as possible to obtain reasonable estimates of the yearly utilization rates by several approaches. For the University Research Forest fifteen different formulae and methods were selected for comparison, because their basic assumptions appeared applicable to this forest. The methods and formulae tested were: Methods: Area regulation, Area-volume check, Area-volume allotment, Barnes’ and H. A. Meyer's. Formulae: Austrian, Black Hills, Grosenbaugh, Hanzlik, Hundeshagen, Kemp, W. H. Meyer, S. Petrini (compound and simple interest) and Von Mantel. Appropriate inventory techniques were developed in order to collect the necessary information regarding rates of growth, mortality and numbers of trees per acre by diameter classes. Present and future decadal growing stocks were estimated. Simple and compound growth rates, including and excluding ingrowth, for all types were calculated separately for stands over eighty years of age and for stands under eighty years. The inventory was based on the areas and estimates taken from 1961 aerial photographs supplemented by both temporary and permanent sample plots, employing primarily the principles of the point sampling techniques as described by L. R. Grosenbaugh. After substituting the actual data into the formulae and various methods, allowable cut estimates for 3.1, 9.1, 11.1, and 13.1 inches minimum diameter limits were calculated. Allowances were made for an intermediate standard of utilization and for waste, breakage and decay. Considering the inventory and the allowable cut calculations it was found that: 1. Simple area regulation will lead to undesirably large fluctuations in allowable cut. 2. Volume formulae are useful means of determining the yearly harvest volume, though the distribution of the cut on the ground requires definition in terms of area as well. 3. Neither area nor volume control can be used exclusively. Some combination and integration is usually necessary in actual practice. In the case of the Research Forest this can be applied most conveniently by following the area-volume computation basis. / Forestry, Faculty of / Graduate

In Europe, the origin of older Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) plantations is generally unknown. The tracing of the probable origin of one Swiss and twenty Polish Douglas-fir stands was attempted. Cone and seed characteristics were measured on material collected from all twenty-one European stands, and compared with the displayed variation of the same characteristics from Douglas-fir growing in its natural range on the Pacific Coast of North America. A seed morphology test, as described by Allen (1960), was used to indicate the Coastal or Interior origin of the samples. Based on this test, the stands from Boezingen/Switzerland and from Purda Lesna/ Poland proved both to be of Coastal origin. A direct comparison of averages of six cone characteristics (width and length of cone scale, width of bract, length of first and second prong, and rating of bract) with the ranges of averages of these characteristics as they vary in climatic seed collection zones of the natural range (Yao [1971]) did not allow an unequivocal assessment of origin. From these comparisons, it could be concluded that cone scale and bract width are more influenced by the environment than the other characteristics. The six characteristics of cone morphology, one thousand-seed weight (measured or assessed on 124 samples from the natural range) and relative DNA content (measured on thirty-six samples of the Coastal part of the natural range) were used concurrently to perform discriminant analyses based on different subspecies, climatic and latitudinal groupings. The discriminant functions obtained were then used to classify the twenty-one provenances of unknown origin. Their origin was assessed at the intersection of the groups to which they were attributed in the different analyses. The low number of provenances, when compared with the immense natural range, and the low number of characteristics taken into consideration, did not allow a complete separation of the groups of provenances. Therefore, the assessment of origin based on cone and seed morphology is still to be considered with caution. Pre-established curvilinear regressions of relative DNA content of embryo cells on latitude in both Coastal and Interior Douglas-fir (El-Lakany and Sziklai [1971, 1972]), were used for inverse estimation of the latitude of origin. It could be established, by this method, that the stand from Boezingen/Switzerland originates between lat. 44° and 47°N on the Coast. When samples are sufficient from the unknown stand, as was the case for provenance Boezingen, seed characteristics and relative DNA content gave promising indication of the probable origin. / Forestry, Faculty of / Graduate

No description available.

Palynological evidence suggests Nordic agriculturalist settlement in the coastal areas of Västerbotten from ~AD 500. Until then these lands had been inhabited by its native inhabitants: the Sámi (semi-nomadic reindeer hunters/herders). Contact started relatively friendly but increasing Nordic colonisation forced Sámi assimilation in Västerbotten by AD 1300, although they maintained their semi-nomadic lifestyle. To exercise more control over the Sámi, winter markets were erected during the 17th century, where the Sámi traded with Nordic settlers, but were also taxed and educated. Little is known about Sámi and Nordic co-existence outside of these market places, mainly due to a lack of archaeological evidence relating to Sámi activity. This thesis presents the results of high-resolution pollen analysis and radiocarbon dating, applied to establish the impact of both Sámi and Nordic land use in the regions surrounding three market towns. The addition of coprophilous fungal spores, microscopic charcoal and sedimentology successfully allowed the reconstruction of vegetation and land-use changes from AD 1-2000. Small-scale human impact in the boreal forests of northern Sweden can be traced if activity was local to the sampling location, a high temporal resolution and robust chronology are achievable: impacts at a Sámi reindeer herding pen are visible in the pollen record, but are most obvious in the coprophilous fungal spore record, making multi-decadal phases of use and abandonment distinguishable. In the Lycksele region coprophilous fungal spores also suggest a possible link to archaeological evidence of Sámi hunter-gatherers. Pollen of natural sea shore meadows in coastal Västerbotten are recorded as late as the Early Medieval Period. Unfortunately it is impossible to separate out an anthropogenic signal due to similar indicator taxa (Artemisia, Rumex-type, Chenopodiaceae and Poaceae). Sámi activity in the winter market areas, if recorded, is inseparable from the signal of 17th century Finnish settlement, characterised by fire clearance.

Management strategies were compared, including thinning and the production of fuelwood versus larger size-class volume, to develop a management plan for the mesquite woodland of the southern Arizona study site. Pre-commercial thinning of mesquite stands is not economic and the production and separate marketing of the larger size class at current stumpage rates gives only marginally higher returns than fuelwood alone, $9.57/ha/yr compared to $9.13/ha/yr. Equations were developed for prediction of fuelwood volume and for estimating volume in stem pieces 20 cm or greater in diameter. Estimated growth rates were 0.43 m3/ha/yr for the upland areas and 0.84 m3/ha/yr for the riparian areas. The culmination of mean annual increment suggests a rotation age of 40 years.