The source of the pollen preserved within fossil assemblages is one of the most important factors to be considered when attempting to reconstruct fonner vegetation landscapes. Due to its mode of dispersal, at anyone time a pollen assemblage is a spatially aggregated record or pollen from local, extra-local and regional vegetation. Studies of pollen recruitment to lakes with surface inflows have shown that fluvial transport plays a dominant role in the recruitment of pollen to these sites. Pollen assemblage fonnation in lakes is further complicated by lirnnological processes which may affect the stratigraphic 'integrity' of the sediment record. A range of techniques and methodologies have been employed to investigate the influence of recruitment and lirnnological processes on the assemblage characteristics and pollen catchment area of an intennediate sized lake basin with surface inflows. The impact of land-use change OIi sediment yields and sediment sources has also been investigated through the use of mineral magnetic and sediment analytical techniques. The relative importance of aerial and streamborne recruitment has been established by , momtoring of pollen input to the lake from both sources over a 17 month period. Results , confmn the importance of fluvially transported pollen at this site and indicate that between 70-90% Qf the total pollen reaching the lake is derived via inflow streams at the present day. Downstream changes in the composition of streambome pollen caught in Tauber traps submerged within the main inflow stream suggests that at least 35% of the pollen recruited via the inflow is currently derived from 'local' riparian vegetation communities. Spatial and temporal patterns of intra-lake pollen deposition have been assessed by analysis and comparison of 24 surface lake mud samples and the pollen content of two parallel sediment cores. Central surface mud samples exhibit less 'noise' than those from marginal zones. Higher variability in littoral surface sediments, as measured by mean, standard deviation and coefficient of variation values of individual pollen types, is thought to reflect high deposition from lake marginal vegetation as well as limnological factors such as water turbulence. A greater diversity of pollen types were found in streamborne assemblages but in other respects percentages of the major pollen types in air, stream and surface lake samples were very similar. Comparison of the pollen, magnetic and sedimentological characteristics of parallel cores taken from the central lake area show close downcore strati graphic correspondence over the topmost 80cm. The shallowness of the lake does not appear to have produced any noticeable discontinuities or non-unifonn patterns of pollen and sediment deposition in central zones. . The effective pollen catchment area of the lake has been established by determining the 'sensitivity' of radiometrically dated lake pollen profiles to vegetation changes at different spatial scales within the landscape, established from documentary records of local and regional land-use and woodland history. From these data it is estimated that c. 70% of the pollen recruited to the lake originates from vegetation growing within c. 2.0 km of the lake. This conclusion contrasts with models of pollen recruitment proposed for similar sized lakes without inflow streams where a significant regional component (>60%) is predicted. Results suggests that the single largest contribution to total influx comes from stream marginal vegetation. A lakewide change in sediment type is recorded after Enclosure in 1789, as the focus of arable activity shifted from outside to inside the lake's drainage catchment. Mineral magnetic properties of lake sediment and catchment soils and sediments also indicate a shift in the source of allochthonous inputs reaching the lake at this time, from subsoil to topsoil derived material. Estimated inorganic sediment yields over the last 50 years are Iow when compared to similar sites with high lake/catchment ratios.

No description available.

Diss. Stockholm : Stockholms universitet, 2005.

<p>Semi-natural grasslands, which are a declining and fragmented habitat in Europe, contain a high biodiversity, and are therefore of interest to conservation. This thesis examines how plant diversity is influenced by the landscape context, and how plant and fungal diversity can be targeted by practical conservation using indicator species and congruence between species groups. Reproduction and recruitment of the dioecious herb <i>Antennaria dioica </i>was also investigated, providing a case study on how fragmentation and habitat degradation may affect grassland plants.</p><p>Grassland size and heterogeneity were of greater importance for plant diversity in semi-natural grassland, than present or historical connectivity to other grasslands, or landscape characteristics. Larger grasslands were more heterogeneous than smaller grasslands, being the likely reason for the species-area relationship.</p><p>A detailed study on <i>A. dioica </i>discovered that sexual reproduction and recruitment may be hampered due to skewed sex-ratios. Sex-ratios were more skewed in small populations, suggesting that dioecious plants are likely to be particularly sensitive to reduced grassland size and fragmentation.</p><p>A study on indicators of plant species richness, used in a recent survey of remaining semi-natural grasslands in Sweden, revealed several problems. A high percentage of all indicator species were missed by the survey, removing an otherwise significant correlation between indicator species and plant species richness. Also, a null model showed that the chosen indicator species did not perform significantly better than species chosen at random from the available species pool, questioning the selection of the indicators in the survey. Diversity patterns of the threatened fungal genus <i>Hygrocybe</i> were not congruent with plant species richness or composition. Plants are thus a poor surrogate group for Hygrocybe fungi, and probably also for other grassland fungi. Implications from this thesis are that conservation of semi-natural grasslands should target several species groups, and that an appropriate scale for plant conservation may be local rather than regional.</p>

Semi-natural grasslands, which are a declining and fragmented habitat in Europe, contain a high biodiversity, and are therefore of interest to conservation. This thesis examines how plant diversity is influenced by the landscape context, and how plant and fungal diversity can be targeted by practical conservation using indicator species and congruence between species groups. Reproduction and recruitment of the dioecious herb Antennaria dioica was also investigated, providing a case study on how fragmentation and habitat degradation may affect grassland plants. Grassland size and heterogeneity were of greater importance for plant diversity in semi-natural grassland, than present or historical connectivity to other grasslands, or landscape characteristics. Larger grasslands were more heterogeneous than smaller grasslands, being the likely reason for the species-area relationship. A detailed study on A. dioica discovered that sexual reproduction and recruitment may be hampered due to skewed sex-ratios. Sex-ratios were more skewed in small populations, suggesting that dioecious plants are likely to be particularly sensitive to reduced grassland size and fragmentation. A study on indicators of plant species richness, used in a recent survey of remaining semi-natural grasslands in Sweden, revealed several problems. A high percentage of all indicator species were missed by the survey, removing an otherwise significant correlation between indicator species and plant species richness. Also, a null model showed that the chosen indicator species did not perform significantly better than species chosen at random from the available species pool, questioning the selection of the indicators in the survey. Diversity patterns of the threatened fungal genus Hygrocybe were not congruent with plant species richness or composition. Plants are thus a poor surrogate group for Hygrocybe fungi, and probably also for other grassland fungi. Implications from this thesis are that conservation of semi-natural grasslands should target several species groups, and that an appropriate scale for plant conservation may be local rather than regional.

Although semi-natural grasslands in Europe are declining there is often a time delay in the local extinction of grassland species due to development of remnant populations, i.e., populations with an extended persistence despite a negative growth rate. The objectives of this study were to examine the occurrence of remnant populations after abandonment of semi-natural grasslands and to examine functional traits of plants associated with the development of remnant populations. We surveyed six managed semi-natural grasslands and 20 former semi-natural grasslands where management ceased 60-100 years ago, and assessed species response to abandonment, assuming a space-for-time substitution. The response of species was related to nine traits representing life cycle, clonality, leaf traits, seed dispersal and seed mass. Of the 67 species for which data allowed analysis, 44 species declined after grassland abandonment but still occurred at the sites, probably as remnant populations. Five traits were associated with the response to abandonment. The declining but still occurring species were characterized by high plant height, a perennial life form, possession of a perennial bud bank, high clonal ability, and lack of dispersal attributes promoting long-distance dispersal. Traits allowing plants to maintain populations by utilizing only a part of their life cycle, such as clonal propagation, are most important for the capacity to develop remnant populations and delay local extinction. A considerable fraction of the species inhabiting semi-natural grasslands maintain what is most likely remnant populations after more than 60 years of spontaneous succession from managed semi-natural grasslands to forest. / <p>authorCount :3</p>

xxii, 272 p. : ill. (some col.), maps (some col.) / Historic campgrounds on National Forest Service lands are a key location where the public experiences the intersection of natural and cultural resources. In the Pacific Northwest Region, the majority of historic Forest Service campgrounds date from the Civilian Conservation Corps/New Deal era of the 1930s; however, some existed previous to this period. Overall, these campgrounds were envisioned, designed, and evolved in an era of rapid technological change, when increasing industrialization, urbanization, and rural accessibility facilitated a cultural need for both preservation of and accessibility to natural resources. In order to understand how these campgrounds evolved over time, existing campground conditions were documented using a case-study approach, based on historic integrity, range of geographic accessibility, and historical data availability. In order to understand what changes have occurred over time, existing and historic conditions were compared. Based on the results, broad cultural landscape stewardship recommendations are made. / Committee in charge: Robert Z. Melnick, FASLA Chairperson; Donald Peting, Member

Before the American small town was enshrined as an ideal, it was a space of dynamic and pioneering progressive reform, a narrative that has been largely untold in histories of professional planning and landscape history. Archival research shows that village improvement was not simply a prequel to the City Beautiful in the years following the 1893 Chicago Expo, but a rich and complex history that places the residential village at the center of debates about the middle landscape as a civic realm comprised of complimentary and oppositional pastoral and urban worldviews. The second half of the nineteenth century saw an extensive movement in village improvement that affected the physical, economic, and social infrastructure of rural settlements of all sizes in every region of the country. As a concept referenced by planners working on comprehensively-designed suburban communities, the small town ideal has never been historicized with respect to the history and theory of the nineteenth century village landscape improvements. This study broadens the study of village improvement to include the history of ideas and debates surrounding rural development on the national and local level between the 1820s and 1880s and, in doing so, argues that the discussion-born theory of village improvement within a national rural reform movement led by some of the nineteenth century's most respected and influential reformers including B.G. Northrop (education), Col. George Waring (sanitation), N.H. Egleston (conservation), Isabella Beecher Hooker (women's rights), and F.L. Olmsted, Sr. (landscape architecture) was modeled on the Laurel Hill Association in Stockbridge, Massachusetts, and that the local practice of this one society over the same period in line with the national movement together comprised the most active sustained discussion about the civic society and physical infrastructure of rural settlements in American history. This narrative tracks reform movements in rural settlements over several decades, beginning with landscape gardening through sanitation and up to the professionalization of city planning and the country life movement. Planning veered from broadly conceived urban pastoralism and multi-disciplinary rural improvement that viewed the village as an extension of the city toward preservation planning that viewed the small town as an increasingly idealized pastoral space, past-looking and unchanging. This trend was in line with an associated shift from planning as a series of fine-grained locally led practices to expert-driven professionalized planning as grandiose comprehensive vision.

This thesis investigates how the inhabitants formed the coastal landscape of northwest Estonia through both internal change and external impact by estate owners, provincial government and imperial decrees. Two villages on the largely Swedish populated Noarootsi peninsula, Einbi (Enby) and Kudani (Gutanäs), are examined in detail. The aim was to answer questions about how the local livelihoods and farming systems of coastal inhabitants changed from the late 1600s to 1940. The background of a gradual weakening of the manorial estate system from 1800 onwards and a rapid development of freehold family farming from the 1860s is important to the analysis. To examine the complex variety of factors and interactions that shape the landscape, an interdisciplinary approach to change has been used. This approach included a conceptual model for the local production unit, such as the individual farm. Information from historical maps, diverse population registers and agricultural censuses were used. The soil cover was examined with samples taken during fieldwork in the studied villages. The study shows how the development of two villages in fairly similar geographic settings differed largely due to socio-political restrictions. During feudal times, the primary changes were related to the fact that local nobility could maintain their land ownership rights and regulations for manorial deliveries and corvée duties. Changes to natural conditions, such as soil quality and land uplift, had no substantial effect on land productivity. From the 19th century, the most important factor was the legalized opportunity to purchase farms as freeholds from estates, as well as through land reforms in an independent Estonia. The traditional niche of coastal Swedish peasants, who depended on a variety of productive activities, remained in practice. As all manor land was nationalized, many new smallholdings and crofts were created based on external activities by inhabitants, such as farm day labor. Farm productivity was now increased primarily by improvement to land quality (use of artificial fertilizers and meadow drainage), and by the introduction of new implements and crops on farms consolidated from open fields.

The paper maps the community of Common Juniper (Juniperus Communis) encountered at Konrac, a site included in the Česká Kanada Nature Preserve. The site itself, or rather the common juniper growing there, does not have the benefit of special legal protection; consequently, no targeted steps have been taken to maintain the juniper community intact in the Konrac landscape - still, the site allowed to monitor the natural development of the community in conditions typical of the current methods of farming. The locality is described to encompass four main types of habitats: stony islands amid meadows; unplowed strips of land around former small fields; peripheries of open stands; and peripheries of close stands. The acquired (and subsequently processed) data point to the conclusion that the habitat at the unplowed margins of fields suits the common juniper communities quite well, even without any human intervention in the farming practices beyond what is implemented on the site now.