Patterns Of Community Development Research Articles

A general model for simulating the effects of landscape heterogeneity and disturbance on community patterns

An individual-based, spatially explicit stochastic lattice model, CAPS, was designed to examine multiple processes responsible for spatial patterns of abundance and diversity of sessile species in heterogeneous landscapes. Species simulated by CAPS differ in habitat preferences (niche width), dispersal of propagules, and relative fecundity. The spatial distribution of habitat types are represented as heterogeneous gridded landscapes. The outcome of competition and establishment processes in successive generations is determined locally via a seed lottery. A series of 200 year-long simulations was performed to investigate the effects of variation in species characteristics and competition, landscape heterogeneity, and disturbance on patterns of species abundances. The outcome of competition was most sensitive to differences in fecundity between species, the spatial distribution of suitable habitat and the initial distribution of species. Species with a narrow niche were confined to a single habitat type and remained at or near their initialization sites. Broader niches resulted in increasing niche overlap and competition but enhanced species mobility, allowing abundance levels to approach expected values determined by map resources. Even so, initial distributions still affected the spatial patterns of species distributions at year 200. Disturbance regimes were simulated by varying the frequency, extent and spatial pattern of disturbances. Disturbance events removed species from affected sites but did not otherwise alter habitat characteristics. Results showed that disturbances may lead to a reversal in competition and establishment, dependent on species-specific differences in fecundity and dispersal. Although intermediate levels of disturbance frequency and extent increased the probability of species coexistence, the spatial pattern of disturbance played an unexpectedly important role in the tradeoff between dispersal and fecundity. The ability to simulate multiple factors affecting patterns of persistence, abundance and spatial distribution of species provided by CAPS allows new insight into the temporal and spatial patterns of community development.

Small scale variability of benthic assemblages: biogenic neighborhood effects.

In this study, patterns of community development were investigated within vs. outside 'habitats'. These habitats represented five different monospecific assemblages of one of the following species: the brown alga Fucus serratus, the red alga Delesseria sanguinea, the green alga Enteromorpha intestinalis, the seagrass Zostera marina and the blue mussel Mytilus edulis. Natural assemblages were allowed to develop on paired artificial substrata-separated by ca. 1 m-within (treatment) vs. outside (control) of habitats. The same colonizer species settled on treatment and control substrata for given habitats. However, after 5 months of settlement and post-settlement dynamics, their proportional abundance and the structure of treatment and control assemblages differed in many instances. Variability among replicates of a given treatment, seperated by up to 50 m, was large, indicating a patchy spatial distribution of organisms. Despite this spatial heterogeneity among within-treatment replicates, analysis of similarity revealed that in most instances significantly different assemblages developed between treatments on a small spatial scale depending on whether substrata were positioned within as compared to outside a given habitat.Consequently, the algae, seagrass or mussels constituting a habitat seem to control the structure of the benthic assemblage developing in their vicinity by one or more possible mechanisms: reduction of larval advection, exudation of metabolites that influence settlement and/or post-settlement survival, and/or-in the case of mussel assemblages-predation on larvae.In addition to spatial variability in larval supply, stochasticity in succession, substratum heterogeneity, competition and predation effects, this investigation reveals the potential of a further assemblage structuring factor: the impact of neighboring organisms.

Community-based disaster management during the 1997 Red River Flood in Canada.

This paper examines the relationship between community preparedness and response to natural disaster and their level and pattern of community development. This is done by investigating preparation and response to the 1997 Red River Flood by three rural communities in Manitoba, Canada. The communities were selected because of their different ethnic mix and associated level and pattern of community development. The hypothesis was supported that the level and pattern of community development affect community capacity to respond to flooding. Communities characterised by higher levels of physical, human and social capital were better prepared and more effective responders to the flood. However, where the pattern of community development was characterised by high levels of social capital, decision-making processes were complicated.

Settlement on concrete blocks immersed in the Ligurian Sea (N-W Mediterranean)

Within the framework of a study on the behaviour of recycled materials in the sea, cubic concrete blocks (used as control material) were immersed at two different locations (Loano and Lavagna) in the Ligurian Sea. The study started in November 1993 and ended in December 1994. In order to gain an idea of the different settlement periods and of the subsequent evolution of the population present on the substrata, these concrete blocks were taken away for faunal analysis and replaced by new blocks every three months. Each block settlement was described, both in terms of quality (species present) and quantity (covering indices, wet weight, dry weight and ash weight). The total number of taxa found in the two localities was 53, 26 of which were common to both sites. The pattern of community development was quite similar and the one year biomass was slightly higher in Loano with 14.2 g/dm 2 of wet weight (8.3 dry weight, 6.7 ash weight) while, in Lavagna, 12.2 g/dm 2 wet weight (6.7 dry weight, 6.1 ash weight) was reached.

道の空間構造からみた農村集落の景観整備に関する研究 : 滋賀県甲良町における整備手法

Based on field research in Koura-chou, Shiga Prefecture, this paper demonstrates that the visual environment of rural areas is dependent on the spatial structure of the boundary between public and private which forms road space, and also discusses how this finding can be put to use in community development The main points can be summarized as follows 1) Roads are divided into three typs, namely intra-community roads, inter-community roads ad inter-city roads, their respective attributes also being outlined. 2) Intra-community roads are rich spaces which reflect the history, culture and ecological stock of the locale. Inter-community roads are affected by as yet untouched farm land consolidation. Inter-city roads show no evidence of local attributes. 3) Koura-chou offers a concrete example of community development which is both sensitive to these findings as well as to local history and culture. 4) By conducting a series of community development workshops, Koura-chou is laying the foundations for the next generation to continue this pattern of community development

Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761-1850.

Journal Article Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761–1850. By P. Jeffrey Potash. (Brooklyn: Carlson, 1991. xvi + 277 pp. $60.00, ISBN 0-926019-52-X.) Get access David G. Hackett David G. Hackett University of Florida Search for other works by this author on: Oxford Academic Google Scholar Journal of American History, Volume 79, Issue 4, March 1993, Pages 1585–1586, https://doi.org/10.2307/2080241 Published: 01 March 1993

Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761–1850. By P. Jeffrey Potash. Chicago Studies in the History of American Religion 16. Brooklyn: Carlson Publishing Inc., 1991. xiv + 277 pp. $60.00.

Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761–1850. By P. Jeffrey Potash. Chicago Studies in the History of American Religion 16. Brooklyn: Carlson Publishing Inc., 1991. xiv + 277 pp. $60.00.

Vermont's burned-over district: patterns of community development and religious activity, 1761-1850

Vermont's burned-over district: patterns of community development and religious activity, 1761-1850

Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761-1850

Vermont's Burned-Over District: Patterns of Community Development and Religious Activity, 1761-1850

Community Development Analysis through Behavioral Patterns

Previous research has provided insight into the process of community growth and development, but a comprehensive field theory involving the measurement of overall development and well-being of a particular community has been lacking. In studying the town of Colmar Manor, Maryland, a model was used to understand the complex and interdependent patterns of community development. Because communities exhibit many of the same growth processes as an individual, a development framework, first designed to study human behavior, was adapted to measure, analyze and predict community growth and development. In the analysis, information was collected and summarized as a community case study. The results showed what areas lacked growth and what improvements should be implemented for development. The study also revealed that the proposed model is a valuable instrument for measuring community development and facilitating community planning.

FUNGAL POPULATION AND COMMUNITY DEVELOPMENT IN CUT BEECH LOGS: III. SPATIAL DYNAMICS, INTERACTIONS AND STRATEGIES.

The spatial development, in beech logs exposed to air-borne and soil-borne inoculum, of mature fungal communities containing mutually or unilaterally exclusive mycelia of decay species is described and related to the ecological strategies and interaction of participant individuals. A combative heirarchy is recognized between (i) ruderal and/or stress-tolerant individuals which are spatially dominant early on and then decline, through (ii) air-borne combative individuals of decay fungi, such as Coriolus versicolor (L. ex Fr.) Quél. and Stereum hirsutum (Willd. ex Fr.) S. F. Gray, which establish mutually exclusive decay columns expanding away from the aerial cut surface, and culminating with (iii) highly combative individuals of mycelial cord-formers such as Phallus impudicus (L.) Pers. and Phanerochaete velutina (DC ex Pers.) Parmasto, which invade slowly from the base, ultimately occuping large volumes of wood, causing intense decay, and replacing many of the pioneers. Addition of basidiospore suspensions of Bjerkandera adusta (Willd. ex Fr.) Karst., C, versicolor, Hypholoma fasciculare (Huds. ex Fr.) Kummer or S. hirsutum to the aerial cut surface appeared to affect community dynamics and functioning markedly. Development of decay columns by air-borne fungi was inhibited and associated with enhanced vertical penetration by basally-colonizing fungi, and persistence of the relatively non-combative species Xylaria hypoxylon (L. ex Hooker) Greville and Armillaria bulbosa. (Barla) Kile & Watling. Re-cutting of the aerial cut surface resulted in community development patterns somewhat intermediate between those in naturally colonized and inoculated logs.

Herbivory and Structure in a Midlittorial Rocky Community: A Case in Southern Chile

The abundance of the red alga Iridaea boryana and the role of herbivores in structuring the mid—intertidal community were studied during a 2—yr period at a semiprotected site in Mehuin, Chile. Herbivore densities wee manipulated on three contiguous rocky areas having similar initial communities. In one treatment, herbivores were totally removed every 15 d.; herbivores were maintained at double the control density in a second treatment; and an undisturbed area was used as a control. Percent cover of sessile organisms was measured at monthly intervals from September 1978 to September 1980. Changes which occurred in the 2—yr period are interpreted as follows. Herbivore removal allowed high cover (>80%) of I. boryana. Herbivore addition and a natural increase in herbivores on the control caused a drastic decline in this alga, and the substrate became dominated by barnacles and crustose algae. Ephemeral algae (e.g., Petalonia and Scytosiphon) were frequent in the presence of herbivores (control and addition), while in the absence of herbivores, invasion by ephemerals was precluded by the high abundance of I. boryana. In winter, herbivores and high wave action caused a significant reduction in algal abundance, which did not occur on the removal rock. Light seemed to be the main limiting resource in the absence of herbivores, where I. boryana was the competitive dominant. Two patterns of community development were found after new space (burned and scraped) was created. (1) Succession following spring denudations began with algal colonization leading to a dominance of I. boryana. (2) Succession following autumn denudations began with barnacles and terminated in a community dominated by barnacles and crustose algae. The natural regional mosaic of I. boryana dominance and barnacles plus crustose algae depends, locally, on the season of the last disturbance and on herbivore abundance. Differences between this southern Chilean and equivalent North American intertidal communities are discussed.

Evolution of late Frasnian (Late Devonian) marine environments in New York and the central Appalachians

Palaeoenvironmental and palaeoecological analyses of late Frasnian (early Late Devonian) strata and fauna in New York and the central Appalachians of the United States reveal strikingly similar patterns of basin filling and evolution. Marine environments of both the upper West Falls Group in New York and the lower Foreknobs Formation in the central Appalachians were characterized by rapid delta progradation and steep offshore submarine gradients. Following a brief marine transgression, basin conditions of the overlying Java Group in New York and the upper Foreknobs Formation in the central Appalachians were quite different. Sedimentation decreased in intensity and the basin was much shallower, with a broad sublittoral shelf and gentle offshore gradients. The gentler environmental gradients of Java-late Foreknobs time yield a three-fold pattern of community development along an onshore-offshore transect in contrast to a two-fold pattern in the earlier late West Falls-early Foreknobs environments. Communiti...

The modular integrated utility system (MIUS) as a potential influence on community development

The Department of Housing and Urban Development (HUD) is conducting the Modular Integrated Utility System (MIUS) Program devoted to development and demonstration of the technical, economic, and institutional advantages of integrating the systems for providing all or several of the utility services for a community. Possible utility services include the provision of electric power, domestic heating and cooling, potable water, fire protection water, liquid waste treatment, and solid waste management. The objective of the MIUS concept is to provide the desired utility services in a way that is consistent with reduction in the use of critical natural resources, protection of the environment, and minimization of cost. A MIUS might be sized to accommodate several hundred or a few thousand multifamily dwelling units, nearby single-family housing, and associated commercial facilities. The MIUS is modular in that it can be installed near appropriate users in phase with the actual demands of community development or redevelopment. It uses an integrated systems approach whereby some resource requirements of one service are met by utilizing the effluent of another. For example, heat rejected from electrical generation might be used for residential space heating, and the efflluent from liquid waste treatment might be used for fire protection and/or cooling tower water. This paper summarizes the MIUS concept and the type and extent of potential application. Possible interactions between MIUS and the local community are identified from a comparison of technological and physical characteristics of MIUS with alternative conventional utilities. Possible impacts on land use and patterns of community development are emphasized.

Observed Community Development Patterns: 1950–1970

Observed Community Development Patterns: 1950–1970