scholarly journals Long‐term demographic surveys reveal a consistent relationship between average occupancy and abundance within local populations of a butterfly metapopulation

Ecography ◽  
2019 ◽  
Vol 43 (2) ◽  
pp. 306-317 ◽  
Author(s):  
Torsti Schulz ◽  
Jarno Vanhatalo ◽  
Marjo Saastamoinen
Keyword(s):  
Local Populations ◽  
Consistent Relationship ◽  
Demographic Surveys ◽  
Average Occupancy

Variation in the recruitment behaviour of seagrass seeds: implications for population dynamics and resource management

1999 ◽  
Vol 5 (4) ◽  
pp. 251 ◽  
Author(s):  
Graeme J. Inglis
Keyword(s):  
Field Studies ◽  
Clonal Plants ◽  
Minor Role ◽  
Spatial And Temporal Scales ◽  
Local Populations ◽  
Seed Supply ◽  
Seed Reserves ◽  
A Minor ◽  
Effective Conservation

Effective conservation of marine organisms requires an understanding of the processes that affect the establishment, persistence and extinction of local populations. Our knowledge of the recruitment of seagrasses comes largely from studies done at small spatial and temporal scales within extant meadows. Descriptions of the demography of local populations, therefore, typically emphasize prolific ramet production and only a minor role for sexual propagules. Recent genetic and field studies, however, have shown greater variation in recruitment behaviour than previously suspected. In this paper, I review what is known about the seeds of seagrasses ? including their dormancy, dispersability and requirements for germination and establishment ? and examine the utility of recent conceptual models, developed for terrestrial clonal plants, to explain the long-term dynamics of seagrass populations. Sizable variation among species in seed size and dispersal strategy appears to be related predictably to variation in life-history and rates of recruitment. Species with small, poorly-dispersed fruits (e.g., Halophila, Halodule) are more likely to form persistent seed reserves and be rapid colonizers of disturbances within established meadows. Genera with large, buoyant fruits, capable of moderate dispersal (e.g., Thalassia, Posidonia), in contrast, appear to recruit rarely within existing meadows of conspecifics. Our ability to model long-term changes in demography and community structure is likely to benefit from a better knowledge of the importance of seed supply and microsite availability to recruitment.

When do ties bind? Foreign fighters, social embeddedness, and violence against civilians

2019 ◽  
Vol 56 (2) ◽  
pp. 279-294 ◽  
Author(s):  
Pauline Moore
Keyword(s):  
Civil Wars ◽  
Empirical Support ◽  
Local Populations ◽  
Rebel Groups ◽  
Conflict Zone ◽  
Violence Against Civilians ◽  
Foreign Fighters ◽  
The Impact ◽  
Negative Connotation

How do foreign fighters affect civilian victimization in the civil wars they join? Scholars of civil war have gone to great lengths to explain why states and insurgent groups victimize civilians, but they have not explicitly examined the impact of foreign combatants. Furthermore, while contemporary conventional wisdom attaches an overwhelmingly negative connotation to foreign fighters, history shows that the behavior of those who travel to fight in wars far from home varies significantly, especially when it comes to interacting with local populations. To address this variation, I demonstrate how differences in the embeddedness of foreign fighter populations combine with incentives that foreign fighters face to remain in the conflict zone over the long term to shape tendencies towards civilian victimization. My findings from an analysis of insurgent groups from 1990 to 2011 suggest that, overall, foreign fighters lead to escalations in violence against civilians. When comparing across groups that recruit foreign fighters, however, levels of violence differ depending on foreign fighter populations’ coethnicity to the rebel groups they join, and the distances they travel to reach a conflict zone. Specifically, the presence of coethnic foreign fighters leads to fewer escalations in violence, relative to the recruitment of non-coethnic individuals from non-neighboring states. The study provides empirical support to the claim that degrees of embeddedness across foreign fighter populations are important indicators of when and where their presence is likely to pose significant dangers to local populations.

scholarly journals Use of forest products by the local people of the Salonga National Park in the Congo

2009 ◽  
Vol 57 (1) ◽  
pp. 51-60
Author(s):  
Jose Mbenga Ibesoa
Keyword(s):  
Forest Management ◽  
National Park ◽  
Positive Attitude ◽  
Sustainable Forest Management ◽  
Forest Products ◽  
Local Communities ◽  
Forest Resources ◽  
Rural Populations ◽  
Local Populations

This article attempted to define a compromise making it possible the satisfaction of the material needs of the populations living within the National park of Salonga while ensuring the conservation of long-term forest resources. The management of the forests requires deepened knowledge of the resources and the participation of the local communities, which are the better, informed on of the forest resources. The implementing of a policy on sustainable forest management would be possible by a better integration and participation of the local populations. A survey was carried out in four villages of the National park of Salonga. The results of the investigation show clearly a positive attitude of the rural populations with regard to the forest resources. The diversity of the needs for the population corresponds to the choice of the products and services of the forest. Overall, the potential of the park’s forests is superior in comparison with the needs of the population. The exploitation of the forest products is vast and is included in the category of a system of an economy of collection.

Forced migration, environmental change and woodfuel issues in the Senegal River Valley

1997 ◽  
Vol 24 (3) ◽  
pp. 251-260 ◽  
Author(s):  
RICHARD BLACK ◽  
MOHAMED F. SESSAY
Keyword(s):  
Environmental Change ◽  
Environmental Impacts ◽  
Direct Measurement ◽  
Forced Migration ◽  
Household Survey ◽  
Environmental Damage ◽  
Senegal River ◽  
Local Populations ◽  
Policy Measures

There is increasing international concern about the environmental impacts of refugees on host areas, with governments calling for compensation for environmental damage, particularly concerning the loss of woodland resources as a result of demand for wood for fuel. In addition to an obvious increase in the population of host areas, concern about refugees' woodfuel-use centres on the notion that they are 'exceptional resource degraders'. Since they view their stay as temporary, it is argued, they therefore do not have any incentive to use resources in a way that is sustainable in the long term. This study examined refugee migration to the middle valley of the Senegal River, and compared woodfuel use by refugee and local populations. Drawing on a household survey and direct measurement of woodfuel use, little or no evidence is found to support the expectation that refugees use more wood for fuel than local people, or that they are more destructive in their collection or use of wood. This is important since it suggests that policy measures developed to reduce what is perceived as excess demand by refugees, notably through the introduction of fuel-efficient stoves, are unlikely to be successful. Reforestation schemes have been relatively unsuccessful in addressing supply or demand for wood.

scholarly journals Local populations facing long-term consequences of nuclear accidents: lessons learnt from Chernobyl and Fukushima

2016 ◽  
Vol 51 ◽  
pp. S155-S158 ◽  
Author(s):  
S. Baudé ◽  
G. Heriard-Dubreuil ◽  
I.-M. Eikelmann ◽  
D. Boilley ◽  
T. Schneider
Keyword(s):  
Nuclear Accidents ◽  
Local Populations ◽  
Lessons Learnt ◽  
Long Term Consequences

Environmental significance of elevated natural levels of arsenic

1995 ◽  
Vol 3 (2) ◽  
pp. 212-221 ◽  
Author(s):  
José M. Azcue
Keyword(s):  
Arsenic Content ◽  
Well Water ◽  
Environmental Significance ◽  
Natural Sources ◽  
Geological Materials ◽  
Local Populations ◽  
Arsenic In Groundwater ◽  
The World ◽  
High Arsenic

Globally, arsenic introduced into the biosphere by human activities has greatly surpassed arsenic from natural sources, the supply of the element from these two sources being approximately 60 and 40%, respectively. However, numerous regions of the world have elevated concentrations of arsenic from natural sources. Arsenopyrite may contain up to 6000 μg∙g−1 of arsenic and the weathering of such geological materials can increase the levels of arsenic in groundwater. Long-term consumption of groundwater containing elevated concentrations of arsenic has caused natural chronic arsenic intoxication in local populations in Taiwan, Mexico, Chile, Argentina, and other countries. An endemic disease commonly called blackfoot disease, which is also caused by arsenic in drinking water, was documented in Taiwan in 1963. For more than 80 years local populations had consumed well water with arsenic concentrations as high as 1829 μg∙L−1. The widespread geographical distribution of minerals with high arsenic content suggests that many new regions with natural arsenic contamination will be identified in the near future.Key words: arsenic, natural, cycling, chronic, contamination.

scholarly journals Current status of the threatened Dupont's lark Chersophilus duponti in Spain: overestimation, decline, and extinction of local populations

Oryx ◽  
2005 ◽  
Vol 39 (1) ◽  
pp. 90-94 ◽  
Author(s):  
José L. Tella ◽  
Matthias Vögeli ◽  
David Serrano ◽  
Martina Carrete
Keyword(s):  
Habitat Degradation ◽  
Iucn Red List ◽  
European Population ◽  
Current Status ◽  
Isolated Populations ◽  
Local Populations ◽  
Population Sizes ◽  
Line Transects ◽  
Dupont’S Lark

The European population of Dupont's lark Chersophilus duponti, restricted to Spanish steppe, was estimated to be 13,000 pairs in c. 50 populations in 1988. There is, however, recent evidence that this number was overestimated because of the previous use of line transects for estimating population sizes. In 2002–2004 we surveyed 34 previously known local populations in patches of variable size across half of its Spanish distribution. We found 13 (38%) local populations to be extinct, and a total of only 283–339 territories in 17 of the extant populations, seven of which held <5 territories. This census contrasts dramatically with the estimate of c. 3,000 pairs in the same populations in the 1980s. We estimate that the present Spanish population is c. 1,300 pairs. The discrepancy between this and earlier estimates is partly but not entirely due to previous overestimations. Habitat loss due to ploughing, and possibly habitat degradation and the resulting stochastic extinction of small and isolated populations, have contributed to the species' decline. Urgent research is needed to design and manage an adequate network of steppe patches that will ensure the long-term existence of this species. We recommend that Dupont's lark be categorized on the IUCN Red List as Endangered, both globally and nationally within Spain.

scholarly journals Raptors in Bosnia and Herzegovina - their status and perspectives for monitoring development

Acrocephalus ◽  
2012 ◽  
Vol 33 (154-155) ◽  
pp. 173-179
Author(s):  
Dražen Kotrošan ◽  
Ena Hatibović
Keyword(s):  
International Cooperation ◽  
Bosnia And Herzegovina ◽  
Wind Turbines ◽  
Present Status ◽  
Historical Data ◽  
Development Programme ◽  
Financial Resources ◽  
Local Populations

Abstract In the last 150 years, 49 raptor species belonging to the families Pandionidae, Accipitridae, Falconidae, Tytonidae, Strigidae and Laniidae have been recorded in Bosnia and Herzegovina. However, little is known about their populations. In comparison with historical data, their status has changed significantly, while nine species became extinct or probably extinct as breeders. In this paper, data on the present status of raptor populations is presented, as well as problems and the possibilities of developing species monitoring in Bosnia and Herzegovina. So far, no raptor monitoring has been established in the form of a long-term programme. The establishment of such programme is hampered by a number of reasons (lack of observers, lack of financial resources, lack of experience and knowledge, etc.). Monitoring of raptors in Bosnia and Herzegovina is needed to improve knowledge of the local populations as well as to protect these birds and their habitats. Also, this programme would be significant for the studies concerning the construction of various facilities (e.g. wind turbines). One of the important points of the development programme is to mobilize international cooperation and projects to solve current problems

scholarly journals Present-day central African forest is a legacy of the 19th century human history

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Julie Morin-Rivat ◽  
Adeline Fayolle ◽  
Charly Favier ◽  
Laurent Bremond ◽  
Sylvie Gourlet-Fleury ◽  
...  
Keyword(s):  
19Th Century ◽  
Forest Structure ◽  
Interdisciplinary Approach ◽  
Anthropogenic Disturbances ◽  
Human History ◽  
Local Populations ◽  
Silvicultural Practices ◽  
History Of ◽  
The 19Th Century

The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future.

A Questionnaire Technique for Investigating Very Long Term Memory

1970 ◽  
Vol 22 (3) ◽  
pp. 508-512 ◽  
Author(s):  
Elizabeth K. Warrington ◽  
M. Silberstein
Keyword(s):  
Error Analysis ◽  
Multiple Choice ◽  
Long Term Memory ◽  
Term Memory ◽  
Public Events ◽  
Consistent Relationship

A questionnaire technique, based on public events, for quantifying memory over long periods of time, is described. Independent groups of subjects were tested at intervals of six months on a recall and multiple choice version of the questionnaire. A consistent relationship between memory and both age of subject and passage of time was found. An error analysis is presented.

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