Effects of 17α-ethinyl estradiol on the mating system of the sand goby (Pomatoschistus minutus)

In aquatic environments, endocrine disrupting chemicals (EDCs) that interfere with the endocrinology of males and females form a threat to the maintenance of populations. EDCs are a diverse group of natural and manmade chemicals that already at very low concentrations (at nanogram levels) can have severe effects on reproduction by individuals, e.g. complete sex reversal, feminisation of males, impaired reproduction even resulting in near extinction of populations. With regard to fish, despite the extensive literature on physiological effects of EDCs, very little is known about potential population-level effects. In this thesis, I examined how 17α-ethinyl estradiol (EE2), a synthetic estrogen used in oral contraceptive pills, affects the reproductive behaviour of a marine fish, the sand goby (Pomatoschistus minutus). The aims were fourfold. First, I investigated how exposure to EE2 affects courtship and parental care of sand goby males. Secondly, I looked at effects on the mating system and sexual selection. In the third study, I observed the effects of exposure in a social context where exposed males had to compete with non-exposed males for resources and mates. Finally, I studied the effects of exposure on male-male competition and male aggressive behaviour. This work revealed that EE2 exposure impairs the ability of males to acquire and defend a nest, as well as diminishes the attractiveness of males to females by decreasing their courtship and aggressive behaviour. These effects are harmful for a male whose reproductive success is determined by the ability to compete for limited resources and to attract mates. Furthermore, this thesis showed that selection on male size was relaxed after EE2 exposure and male size had a smaller effect on mating success. These effects can be of a profound nature as they interfere with sexual selection, and may in the long run lead to the loss of traits maintained through sexual selection. The thesis shows that an exposure to environmentally relevant levels of EE2 clearly reduces the chances of individuals to reproduce successfully. Furthermore, it strongly suggests that several types of biomarkers should be used to detect and assess the effects of EDC exposure because severe behavioural effects can sometimes be seen before effects are detectable at the molecular or morphometric level. Behavioural assays should be considered an important complementary tool for the standard ecotoxicological assays because observed behavioural changes have direct and negative effects on fitness, while the connection between changes in molecular expression and fitness may be less obvious.

Context-dependent mate choice in the sand goby, Pomatoschistus minutus

The results presented in this thesis show that all females of a given population do not necessarily choose similar mating partners. Specifically, partner preferences of a fish, the sand goby (Pomatoschistus minutus), varied among individual females and depended on the social context at the time of choice. I also show that females assess multiple mate choice cues simultaneously; partner preferences were based more strongly on an interaction effect between different choice cues than on any individual cue. Furthermore, I found that preferred matings involved fitness benefits in the form of increased offspring success, but these benefits were not significantly affected by mate compatibility. Hence, mate choice for partner compatibility does not appear to be an important determinant of the observed variation in female mate preferences in this species. The context-dependency of female mating preferences revealed is relevant to how genetic variation in sexually selected traits might be maintained: as the mating success of a certain male type varies according to the choice context, directional sexual selection on male traits is shown to be less intense than generally thought making for a slower loss of genetic variation in these traits. Mating preferences of sand gobies were assessed by giving females a binary choice between males that differed in body size and/or other focus traits. These association preferences were found to be sexually motivated, repeatable and to correspond to actual mating decisions.

Tropical dryland agroforestry on clay soils: : Analysis of systems based on Acacia senegal in the Blue Nile region, Sudan

Acacia senegal, the gum arabic producing tree, is the most important component in traditional dryland agroforestry systems in the Blue Nile region, Sudan. The aim of the present study was to provide new knowledge on the potential use of A. senegal in dryland agroforestry systems on clay soils, as well as information on tree/crop interaction, and on silvicultural and management tools, with consideration on system productivity, nutrient cycling and sustainability. Moreover, the aim was also to clarify the intra-specific variation in the performance of A. senegal and, specifically, the adaptation of trees of different origin to the clay soils of the Blue Nile region. In agroforestry systems established at the beginning of the study, tree and crop growth, water use, gum and crop yields, nutrient cycling and system performance were investigated for a period of four years (1999 to 2002). Trees were grown at 5 x 5 m and 10 x 10 m spacing alone or in mixture with sorghum or sesame; crops were also grown in sole culture. The symbiotic biological N2 fixation by A. senegal was estimated using the 15N natural abundance (δ15N) procedure in eight provenances collected from different environments and soil types of the gum arabic belt and grown in clay soil in the Blue Nile region. Balanites aegyptiaca (a non-legume) was used as a non-N-fixing reference tree species, so as to allow 15N-based estimates of the proportion of the nitrogen in trees derived from the atmosphere. In the planted acacia trees, measurements were made on shoot growth, water-use efficiency (as assessed by the δ13C method) and (starting from the third year) gum production. Carbon isotope ratios were obtained from the leaves and branch wood samples. The agroforestry system design caused no statistically significant variation in water use, but the variation was highly significant between years, and the highest water use occurred in the years with high rainfall. No statistically significant differences were found in sorghum or sesame yields when intercropping and sole crop systems were compared (yield averages were 1.54 and 1.54 ha-1 for sorghum and 0.36 and 0.42 t ha-1 for sesame in the intercropped and mono-crop plots, respectively). Thus, at an early stage of agroforestry system management, A. senegal had no detrimental effect on crop yield, but the pattern of resource capture by trees and crops may change as the system matures. Intercropping resulted in taller trees and larger basal and crown diameters as compared to the development of sole trees. It also resulted in a higher land equivalent ratio. When gum yields were analysed it was found that a significant positive relationship existed between the second gum picking and the total gum yield. The second gum picking seems to be a decisive factor in gum production and could be used as an indicator for the total gum yield in a particular year. In trees, the concentrations of N and P were higher in leaves and roots, whereas the levels of K were higher in stems, branches and roots. Soil organic matter, N, P and K contents were highest in the upper soil stratum. There was some indication that the P content slightly increased in the topsoil as the agroforestry plantations aged. At a stocking of 400 trees ha-1 (5 x 5 m spacing), A. senegal accumulated in the biomass a total of 18, 1.21, 7.8 and 972 kg ha-1of N, P, K and OC, respectively. Trees contributed ca. 217 and 1500 kg ha-1 of K and OC, respectively, to the top 25-cm of soil over the first four years of intercropping. Acacia provenances of clay plain origin showed considerable variation in seed weight. They also had the lowest average seed weight as compared to the sandy soil (western) provenances. At the experimental site in the clay soil region, the clay provenances were distinctly superior to the sand provenances in all traits studied but especially in basal diameter and crown width, thus reflecting their adaptation to the environment. Values of δ13C, indicating water use efficiency, were higher in the sand soil group as compared to the clay one, both in leaves and in branch wood. This suggests that the sand provenances (with an average value of -28.07 ) displayed conservative water use and high drought tolerance. Of the clay provenances, the local one (Bout) displayed a highly negative (-29.31 ) value, which indicates less conservative water use that resulted in high productivity at this particular clay-soil site. Water use thus appeared to correspond to the environmental conditions prevailing at the original locations for these provenances. Results suggest that A. senegal provenances from the clay part of the gum belt are adapted for a faster growth rate and higher biomass and gum productivity as compared to provenances from sand regions. A strong negative relationship was found between the per-tree gum yield and water use efficiency, as indicated by δ13C. The differences in water use and gum production were greater among provenance groups than within them, suggesting that selection among rather than within provenances would result in distinct genetic gain in gum yield. The relative δ15N values ( ) were higher in B. aegyptiaca than in the N2-fixing acacia provenances. The amount of Ndfa increased significantly with age in all provenances, indicating that A. senegal is a potentially efficient nitrogen fixer and has an important role in t agroforestry development. The total above-ground contribution of fixed N to foliage growth in 4-year-old A. senegal trees was highest in the Rahad sand-soil provenance (46.7 kg N ha-1) and lowest in the Mazmoom clay-soil provenance (28.7 kg N ha-1). This study represents the first use of the δ15N method for estimating the N input by A. senegal in the gum belt of Sudan. Key words: Acacia senegal, agroforestry, clay plain, δ13C, δ15N, gum arabic, nutrient cycling, Ndfa, Sorghum bicolor, Sesamum indicum

Environmentally benign Fe chelates in plant nutrition

The low solubility of iron (Fe) depresses plant growth in calcareous soils. In order to improve Fe availability, calcareous soils are treated with synthetic ligands, such as ethylenediaminetetraacetic acid (EDTA) and ethylenediimi-nobis(2-hydroxyphenyl)acetic acid (EDDHA). However, high expenses may hinder their use (EDDHA), and the recalcitrance of EDTA against biodegra-dation may increase the potential of cadmium (Cd) and lead (Pb) leaching. This study evaluated the ability of biodegradable ligands, i.e. different stereo-isomers of ethylenediaminedisuccinic acid (EDDS), to provide Fe for lettuce (Lactuca sativa L.) and ryegrass (Lolium perenne cv. Prego), their effects on uptake of other elements and solubility in soils and their subsequent effects on the activity of oxygen-scavenging enzymes in lettuce. Both EDTA and EDDHA were used as reference ligands. In unlimed and limed quartz sand both FeEDDS(S,S) and a mixture of stereo-isomers of FeEDDS (25% [S,S]-EDDS, 25% [R,R]-EDDS and 50% [S,R]/[R,S]-EDDS), FeEDDS(mix), were as efficient as FeEDTA and FeEDDHA in providing lettuce with Fe. However, in calcareous soils only FeEDDS(mix) was comparable to FeEDDHA when Fe was applied twice a week to mimic drip irrigation. The Fe deficiency increased the manganese (Mn) concentration in lettuce in both acidic and alkaline growth media, whereas Fe chelates depressed it. The same was observed with zinc (Zn) and copper (Cu) in acidic growth media. EDDHA probably affected the hormonal status of lettuce as well and thus depressed the uptake of Zn and Mn even more. The nutrient concentrations of ryegrass were only slightly affected by the Fe availability. After Fe chelate splitting in calcareous soils, EDDS and EDTA increased the solubility of Zn and Cu most, but only the Zn concentration was increased in lettuce. The availability of Fe increased the activity of oxygen-scavenging enzymes (ascorbate peroxidase, guaiacol peroxidase, catalase). The activity of Cu/ZnSOD (Cu/Zn superoxide dismutase) and MnSOD in lettuce leaves followed the concentrations of Zn and Mn. In acidic quartz sand low avail-ability of Fe increased the cobalt (Co) and nickel (Ni) concentrations in let-tuce, but Fe chelates decreased them. EDTA increased the solubility of Cd and Pb in calcareous soils, but not their uptake. The biodegradation of EDDS was not affected by the complexed element, and [S,S]-EDDS was biodegraded within 28 days in calcareous soils. EDDS(mix) was more recalcitrant, and after 56 days of incubation water-soluble elements (Fe, Mn, Zn, Cu, Co, Ni, Cd and Pb) corresponded to 10% of the added EDDS(mix) concentration.

Intensity, productivity and efficiency in agriculture in Finland and implications for N and P fertiliser management

The purpose of this study was to evaluate intensity, productivity and efficiency in agriculture in Finland and show implications for N and P fertiliser management. Environmental concerns relating to agricultural production have been and still are focused on arguments about policies that affect agriculture. These policies constrain production while demand for agricultural products such as food, fibre and energy continuously increase. Therefore the importance of increasing productivity is a great challenge to agriculture. Over the last decades producers have experienced several large changes in the production environment such as the policy reform when Finland joined the EU 1995. Other and market changes occurred with the further EU enlargement with neighbouring countries in 2005 and with the decoupling of supports over the 2006-2007 period. Decreasing prices a decreased number of farmers and decreased profitability in agricultural production have resulted from these changes and constraints and of technological development. It is known that the accession to the EU 1995 would herald changes in agriculture. Especially of interest was how the sudden changes in prices of commodities on especially those of cereals, decreased by 60%, would influence agricultural production. The knowledge of properties of the production function increased in importance as a consequence of price changes. A research on the economic instruments to regulate productions was carried out and combined with earlier studies in paper V. In paper I the objective was to compare two different technologies, the conventional farming and the organic farming, determine differences in productivity and technical efficiency. In addition input specific or environmental efficiencies were analysed. The heterogeneity of agricultural soils and its implications were analysed in article II. In study III the determinants of technical inefficiency were analysed. The aspects and possible effects of the instability in policies due to a partial decoupling of production factors and products were studied in paper IV. Consequently connection between technical efficiency based on the turnover and the sales return was analysed in this study. Simple economic instruments such as fertiliser taxes have a direct effect on fertiliser consumption and indirectly increase the value of organic fertilisers. However, fertiliser taxes, do not fully address the N and P management problems adequately and are therefore not suitable for nutrient management improvements in general. Productivity of organic farms is lower on average than conventional farms and the difference increases when looking at selling returns only. The organic sector needs more research and development on productivity. Livestock density in organic farming increases productivity, however, there is an upper limit to livestock densities on organic farms and therefore nutrient on organic farms are also limited. Soil factors affects phosphorous and nitrogen efficiency. Soils like sand and silt have lower input specific overall efficiency for nutrients N and P. Special attention is needed for the management on these soils. Clay soils and soils with moderate clay content have higher efficiency. Soil heterogeneity is cause for an unavoidable inefficiency in agriculture.

Road Dust from Pavement Wear and Traction Sanding

Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is road dust . The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: i) How do traction sanding and physical properties of the traction sand aggregate affect formation of road dust? ii) How do studded tires affect the formation of road dust when compared with friction tires? iii) What are the composition and sources of airborne road dust in a road simulator and during a springtime road dust episode in Finland? iv) What is the size distribution of abrasion particles from tire-road interaction? The studies were conducted both in a road simulator and in field conditions. The test results from the road simulator showed that traction sanding increased road dust emissions, and that the effect became more dominant with increasing sand load. A high percentage of fine-grained anti-skid aggregate of overall grading increased the PM10 concentrations. Anti-skid aggregate with poor resistance to fragmentation resulted in higher PM levels compared with the other aggregates, and the effect became more significant with higher aggregate loads. Glaciofluvial aggregates tended to cause higher particle concentrations than crushed rocks with good fragmentation resistance. Comparison of tire types showed that studded tires result in higher formation of PM emissions compared with friction tires. The same trend between the tires was present in the tests with and without anti-skid aggregate. This finding applies to test conditions of the road simulator with negligible resuspension. Source and composition analysis showed that the particles in the road simulator were mainly minerals and originated from both traction sand and pavement aggregates. A clear contribution of particles from anti-skid aggregate to ambient PM and dust deposition was also observed in urban conditions. The road simulator results showed that the interaction between tires, anti-skid aggregate and road surface is important in dust production and the relative contributions of these sources depend on their properties. Traction sand grains are fragmented into smaller particles under the tires, but they also wear the pavement aggregate. Therefore particles from both aggregates are observed. The mass size distribution of traction sand and pavement wear particles was mainly coarse, but fine and submicron particles were also present.

Molecular Tuning of Rhodopsins for High Visual Sensitivity in Different Light Environments : Variation in Absorbance Spectrum and Opsin Sequence within and between Species

Visual pigments of different animal species must have evolved at some stage to match the prevailing light environments, since all visual functions depend on their ability to absorb available photons and transduce the event into a reliable neural signal. There is a large literature on correlation between the light environment and spectral sensitivity between different fish species. However, little work has been done on evolutionary adaptation between separated populations within species. More generally, little is known about the rate of evolutionary adaptation to changing spectral environments. The objective of this thesis is to illuminate the constraints under which the evolutionary tuning of visual pigments works as evident in: scope, tempo, available molecular routes, and signal/noise trade-offs. Aquatic environments offer Nature s own laboratories for research on visual pigment properties, as naturally occurring light environments offer an enormous range of variation in both spectral composition and intensity. The present thesis focuses on the visual pigments that serve dim-light vision in two groups of model species, teleost fishes and mysid crustaceans. The geographical emphasis is in the brackish Baltic Sea area with its well-known postglacial isolation history and its aquatic fauna of both marine and fresh-water origin. The absorbance spectrum of the (single) dim-light visual pigment were recorded by microspectrophotometry (MSP) in single rods of 26 fish species and single rhabdoms of 8 opossum shrimp populations of the genus Mysis inhabiting marine, brackish or freshwater environments. Additionally, spectral sensitivity was determined from six Mysis populations by electroretinogram (ERG) recording. The rod opsin gene was sequenced in individuals of four allopatric populations of the sand goby (Pomatoschistus minutus). Rod opsins of two other goby species were investigated as outgroups for comparison. Rod absorbance spectra of the Baltic subspecies or populations of the primarily marine species herring (Clupea harengus membras), sand goby (P. minutus), and flounder (Platichthys flesus) were long-wavelength-shifted compared to their marine populations. The spectral shifts are consistent with adaptation for improved quantum catch (QC) as well as improved signal-to-noise ratio (SNR) of vision in the Baltic light environment. Since the chromophore of the pigment was pure A1 in all cases, this has apparently been achieved by evolutionary tuning of the opsin visual pigment. By contrast, no opsin-based differences were evident between lake and sea populations of species of fresh-water origin, which can tune their pigment by varying chromophore ratios. A more detailed analysis of differences in absorbance spectra and opsin sequence between and within populations was conducted using the sand goby as model species. Four allopatric populations from the Baltic Sea (B), Swedish west coast (S), English Channel (E), and Adriatic Sea (A) were examined. Rod absorbance spectra, characterized by the wavelength of maximum absorbance (λmax), differed between populations and correlated with differences in the spectral light transmission of the respective water bodies. The greatest λmax shift as well as the greatest opsin sequence difference was between the Baltic and the Adriatic populations. The significant within-population variation of the Baltic λmax values (506-511 nm) was analyzed on the level of individuals and was shown to correlate well with opsin sequence substitutions. The sequences of individuals with λmax at shorter wavelengths were identical to that of the Swedish population, whereas those with λmax at longer wavelengths additionally had substitution F261F/Y in the sixth transmembrane helix of the protein. This substitution (Y261) was also present in the Baltic common gobies and is known to redshift spectra. The tuning mechanism of the long-wavelength type Baltic sand gobies is assumed to be the co-expression of F261 and Y261 in all rods to produce ≈ 5 nm redshift. The polymorphism of the Baltic sand goby population possibly indicates ambiguous selection pressures in the Baltic Sea. The visual pigments of all lake populations of the opossum shrimp (Mysis relicta) were red-shifted by 25 nm compared with all Baltic Sea populations. This is calculated to confer a significant advantage in both QC and SNR in many humus-rich lakes with reddish water. Since only A2 chromophore was present, the differences obviously reflect evolutionary tuning of the visual protein, the opsin. The changes have occurred within the ca. 9000 years that the lakes have been isolated from the Sea after the most recent glaciation. At present, it seems that the mechanism explaining the spectral differences between lake and sea populations is not an amino acid substitution at any other conventional tuning site, but the mechanism is yet to be found.

Phylogenetics, taxon delimitation and phylogenetic diversity

Throughout the history of Linnean taxonomy, species have been described with varying degrees of justification. Many descriptions have been based on only a few ambiguous morphological characters. Moreover, species have been considered natural, well-defined units whereas higher taxa have been treated as disparate, non-existent creations. In the present thesis a few such cases were studied in detail. Often the species-level descriptions were based on only a few specimens and the variation previously thought to be interspecific was found to be intraspecific. In some cases morphological characters were sufficient to resolve the evolutionary relationships between the taxa, but generally more resolution was gained by the addition of molecular evidence. However, both morphological and molecular data were found to be deceptive in some cases. The DNA sequences of morphologically similar specimens were found to differ distinctly in some cases, whereas in other closely related species the morphology of specimens with identical DNA sequences differed substantially. This study counsels caution when evolutionary relationships are being studied utilizing only one source of evidence or a very limited number of characters (e.g. barcoding). Moreover, it emphasizes the importance of high quality data as well as the utilization of proper methods when making scientific inferences. Properly conducted analyses produce robust results that can be utilized in numerous interesting ways. The present thesis considered two such extensions of systematics. A novel hypothesis on the origin of bioluminescence in Elateriformia beetles is presented, tying it to the development of the clicking mechanism in the ancestors of these animals. An entirely different type of extension of systematics is the proposed high value of the white sand forests in maintaining the diversity of beetles in the Peruvian Amazon. White sand forests are under growing pressure from human activities that lead to deforestation. They were found to harbor an extremely diverse beetle fauna and many taxa were specialists living only in this unique habitat. In comparison to the predominant clay soil forests, considerably more elateroid beetles belonging to all studied taxonomic levels (species, genus, tribus, and subfamily) were collected in white sand forests. This evolutionary diversity is hypothesized to be due to a combination of factors: (1) the forest structure, which favors the fungus-plant interactions important for the elateroid beetles, (2) the old age of the forest type favoring survival of many evolutionary lineages and (3) the widespread distribution and fragmentation of the forests in the Miocene, favoring speciation.

The effects of stall surfaces and milk yield on the lying behavior of dairy cow

The importance of lying behavior to dairy cows and the feasible definition of lying has attracted many studies on the subject. Cattle show both behavioral and physiological stress responses when subjected to thwarting of their lying behavior. If cows are unable to lie down they later compensate for lost lying time when possible. Environmental factors such as housing and bedding systems have been noted to affect the time spent lying, but there is usually large variation in lying time between individuals. Internal factors such as the reproductive stage, age and health of cows affect their lying time and can cause variation. However, the effect of higher milk production on behavior has not previously been illuminated. The objective of this study was to provide data applicable for the improvement of resting conditions of cows. The preference of stall surface material, differences in normal behavior per unit time and various health measures were observed. The aim was to evaluate lying behavior and cow comfort on different stall bedding materials. In addition, the effect of milk yield on behavior was examined in a tie stall experiment. The preferences for surface materials were investigated in 5 experiments using 3 surface materials with bedding manipulations. According to the results, the cows preferred abundant straw bedding and soft rubber mats. However, they showed an aversion to sand bedding. Some individuals even refused to use stalls with sand when no organic bedding material was present. However, this study was unable to determine the reason for the avoidance, as neither the sand particle size nor thermal properties appeared critical. However, previous exposure to particular surface materials increased the preference for them. The amount of straw bedding was found to be an important factor affecting the preferences for stalls, and the lying time in stalls increased when the flooring softness was improved by applying straw or by installing elastic mats. Despite sand being the least preferred flooring material in preference tests, the health of legs improved during exposure to sand-floored stalls. Moreover cows using sand were cleaner than those that used straw stalls. Thus, sand bedding entailed some health benefits despite the contradictory results of preference tests, which more strongly reflected the perceptions of individual animals. Milk yield was observed to affect behavior by reducing the lying time, possibly due to factors other than longer duration of eating. High yielding cows seemed to intensify their lying bouts, as they were observed to lie with the neck muscles relaxed sooner after lying down than lower yielding cows. In conclusion, cows were found to prefer softer stall surface materials and organic bedding material. In addition, the lying time was reduced by a high milk yield, although the lying time seemed to be important for resting. Cows might differ in the needs for their lying environment. The management of dairy cows should eliminate any unnecessary prevention of lying, as even in tie-stalls high yielding cows seem to be affected by time constraints. Adding fresh bedding material to stalls increases the comfort of any stall flooring material.

Prosopis, an Alien among the Sacred Trees of South India

The problematic of invasive species in an alien environment has aroused the attention of scientists all over the world for quite some time. One of the exotic tree species that has provoked special attention in the tropical drylands is Prosopis juliflora. Originating in South America, prosopis (hereafter referred to as prosopis) has been introduced in the hot and semi-arid zones of the world particularly to provide fuelwood, to stabilize sand dunes and to combat desertification. The tree has become an essential source for fuelwood and a provider of several other products and services in areas where it has become established. However, despite the numerous benefits the tree provides to rural people, in several regions prosopis has become a noxious weed with a negative impact on the environment and to the economy of farmers and landowners. In India, prosopis was introduced in Andhra Pradesh in 1877. The tree was then proclaimed as the precious child of the plant world by scientists and local people alike. The purpose of this study was to investigate the overall impact of prosopis on local rural livelihoods in the drylands of South India. Of particular interest was the examination of the different usages of the tree, especially as fuelwood, and people s perceptions of it. Furthermore, the study examined the negative impacts of the uncontrolled invasion of prosopis on croplands, and its occupation of the banks of irrigation canals and other water sources. As another central theme, this study analysed the Hindu classification system for nature and for trees in particular. In India, several tree species are regarded as sacred. This study examined the position of the exotic prosopis among sacred trees, such as the bodhi, banyan and neem trees. The principle method for collecting the field data was by using individual and thematic group interviews. These interviews were semi-structured with open ended questions. Moreover, unstructured interviews as well as general observations provided complementary information. The data were gathered during two fieldwork periods in the states of Andhra Pradesh and Tamil Nadu, in South India. The results confirmed that prosopis both provides benefits and causes hazards to different stakeholders. Farmers and agriculturalists suffer economic losses in areas where prosopis has invaded crop fields and competes with other plants for water and nutrients. On the other hand, for a significant number of poor rural people, prosopis has become an important source of livelihood benefits. This tree, which grows on government wastelands, is commonly a free resource for all and has thus become a major local source of fuelwood. It also provides several other goods and services and cash income that contributes to improve livelihoods in rural communities. Prosopis ranked lowest in the tree classificatioin system of the Hindus of South India. Although it is appreciated for many benefits it provides for poor people, it has remained an outsider compared with the indigenous tree species. On the other hand, the most sacred trees, such as the bodhi or the banyan, are completely excluded from extraction and it is seen as a sacrilege to even cut branches from any of these trees. An unexpected finding was that, in a few cases, prosopis had also been elevated to the status of a sacred tree. Goods and services from prosopis are not utilized in the most beneficial way. Silvicultural management practices are suggested that would provide additional income and employment opportunities. Interventions are recommended to control further invasion of the tree that might cause serious negative effects in the future. For Hindus, the sacred always ranks highest, even above economic gain. The conservation of sacred groves and sacred trees is a tradition that has its roots in ancient history. These socio-religious practices need to be respected and continued. Successful management of tree and forest resources depends on the willingness of the local people to manage their natural resources, and this willingness exists and has always existed in South India. Keywords: South India, drylands, livelihood, fuelwood, invasive, resource, silviculture.

Rannansiirtyminen ja ihmisen toimintaympäristön muutos Mätäjokilaakson alueella esihistoriallisella ajalla

In this thesis, I study the changing ladscape and human environment of the Mätäjoki Valley, West-Helsinki, using reconstructions and predictive modelling. The study is a part of a larger project funded by the city of Helsinki aming to map the past of the Mätäjoki Valley. The changes in landscape from an archipelago in the Ancylus Lake to a river valley are studied from 10000 to 2000 years ago. Alongside shore displacement, we look at the changing environment from human perspective and predict the location of dwelling sitesat various times. As a result, two map series were produced that show how the landscape changed and where inhabitance is predicted. To back them up, we have also looked at what previous research says about the history of the waterways, climate, vegetation and archaeology. The changing landscape of the river valley is reconstructed using GIS methods. For this purpose, new laser point data set was used and at the same time tested in the context landscape modelling. Dwelling sites were modeled with logistic regression analysis. The spatial predictive model combines data on the locations of the known dwelling sites, environmental factors and shore displacement data. The predictions were visualised into raster maps that show the predictions for inhabitance 3000 and 5000 years ago. The aim of these maps was to help archaeologists map potential spots for human activity. The produced landscape reconstructions clarified previous shore displacement studies of the Mätäjoki region and provided new information on the location of shoreline. From the shore displacement history of the Mätäjoki Valley arise the following stages: 1. The northernmost hills of the Mätäjoki Valley rose from Ancylus Lake approximately 10000 years ago. Shore displacement was fast during the following thousand years. 2. The area was an archipelago with a relatively steady shoreline 9000 7000 years ago. 8000 years ago the shoreline drew back in the middle and southern parts of the river valley because of the transgression of the Litorina Sea. 3. Mätäjoki was a sheltered bay of the Litorina Sea 6000 5000 years ago. The Vantaanjoki River started to flow into the Mätäjoki Valley approximately 5000 years ago. 4. The sediment plains in the southern part of the river valley rose from the sea rather quickly 5000 3000 years ago. Salt water still pushed its way into the southermost part of the valley 4000 years ago. 5. The shoreline proceeded to Pitäjänmäki rapids where it stayed at least a thousand years 3000 2000 years ago. The predictive models managed to predict the locations of dwelling sites moderately well. The most accurate predictions were found on the eastern shore and Malminkartano area. Of the environment variables sand and aspect of slope were found to have the best predictive power. From the results of this study we can conclude that the Mätäjoki Valley has been a favorable location to live especially 6000 5000 years ago when the climate was mild and vegetation lush. The laser point data set used here works best in shore displacement studies located in rural areas or if further specific palaeogeographic or hydrologic analysis in the research area is not needed.

Against the Vagueness Argument

In this paper I offer a counterexample to the so called vagueness argument against restricted composition. This will be done in the lines of a recent suggestion by Trenton Merricks, namely by challenging the claim that there cannot be a sharp cut-off point in a composition sequence. It will be suggested that causal powers which emerge when composition occurs can serve as an indicator of such sharp cut-off points. The main example will be the case of a heap. It seems that heaps might provide a very plausible counterexample to the vagueness argument if we accept the idea that four grains of sand is the least number required to compose a heap—the case has been supported by W. D. Hart. My purpose here is not to put forward a new theory of composition, I only wish to refute the vagueness argument and point out that we should be wary of arguments of its form.

Accessibility as a determinant of opportunities : A case study from Peruvian Amazonia

Accessibility is a crucial factor for interaction between areas in economic, cultural, political and environmental terms. Therefore, information concerning accessibility is relevant for informed decision making, planning and research. The Loreto region in the Peruvian Amazonia provides an interesting scene for an accessibility study. Loreto is sparsely populated and because there are few roads in the region, in practice all movement and transportation happens along the river network. Due to the proximity of the Andes, river dynamics are strong and annual changes in water level combined with these dynamic processes constantly reshape accessibility patterns of the region. Selling non-timber forest products (NTFP) and agricultural products (AP) in regional centres is an important income source for local rain forest dwellers. Thus, accessibility to the centres is crucial for the livelihood of local population. -- In this thesis I studied how accessible the regional centre Iquitos is from other parts of Loreto. In addition, I studied the regional NTFP/AP trade patterns and compared them with patterns of accessibility. Based on GPS-measurements, using GIS, I created a time-distance surface covering Loreto. This surface describes the time-distance to Iquitos, along the river network. Based on interview material, I assessed annual changes to accessibility patterns in the region. The most common regional NTFP/AP were classified according to the amount of time they can be preserved, and based on the accessibility surface, I modelled a catchment area for each of these product classes. -- According to my results, navigation speeds vary considerably in different parts of the river network, depending on river types, vessels, flow direction and season. Navigating downstream is, generally, faster than upstream navigation. Thus, Iquitos is better accessible from areas situated south and south west of the city, like along the rivers Ucayali and Marañon. Differences in accessibility between different seasons are also substantial: during the dry season navigation is slower due to lower water levels and emerging sand bars. Regularly operating boats follow routes only along certain rivers and close to Iquitos transport facilities are more abundant than in more distant areas. Most of the products present in Iquitos market places are agricultural products, and the share of NTFP is significantly smaller. Most of the products were classified in product class 2, and the catchment area for these products is rather small. Many products also belonged to class 5, and the catchment area for these products reaches up to the edges of my study area, following the patterns of the river network. -- The accessibility model created in this study predicts travel times relatively well, although in some cases the modelled time-distances are substantially shorter than observed time-distances. This is partly caused by the fact that real-life navigation routes are more complicated than the modelled routes. Rain forest dwellers having easier access to Iquitos have more opportunities in terms of the products they decide to market. Thus, they can better take advantage of other factors affecting the market potential of different products. -- In all, understanding spatial variation in accessibility is important. In the Amazonian context it is difficult to combine the accessibility-related needs of the local dwellers with conservation purposes and the future challenge lies in finding solution that satisfy both of these needs.