Sprouting, succession and tree species diversity in a South African coastal dune forest

2011 ◽  
Vol 27 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Emmanuel Fred Nzunda
Keyword(s):  
Species Diversity ◽  
South African ◽  
Coastal Dune ◽  
Regeneration Pattern ◽  
Disturbance Frequency ◽  
Structural Variables ◽  
Chronic Disturbance ◽  
Diameter Frequency Distribution ◽  
Shifting Cultivators ◽  
The Relationship

Abstract:Sprouting may play a significant role in maintenance of plant diversity where prevailing disturbance frequency and severity allows. When disturbance frequency and severity decrease, strong sprouters may be outcompeted. As a result, species composition and diversity may change. This study was carried out to investigate the relationship between sprouting, succession and species diversity in a coastal dune forest that currently suffers from low-severity, chronic disturbance due to sea winds and loose sand substrate. Historically, the site was occupied by shifting cultivators who left the site about 80 y ago. Data on trees that were at least 1.3 m tall from 42 sample plots measuring 20 × 20 m were used. The plots were ranked in order of advancement of succession using the first axis of Principal Components Analysis of forest structural variables. Regeneration pattern was examined using analysis of stem diameter frequency distribution. Abundance and regeneration of strong basal sprouters, incidence of basal sprouting and species diversity decreased with advancement of succession. Only a few species could regenerate under the canopy of late-successional sites. Basal sprouts decreased with advancement of succession whereas trunk sprouts increased. These results suggest that maintenance of high species diversity may need a level of disturbance that allows regeneration and maintenance of strong basal sprouters.

Co-creating the Psychological “White Picket Fence”: Three Gay Couples’ Relationship Reconfiguration

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Prevan Moodley ◽  
Francois Rabie
Keyword(s):  
Grounded Theory ◽  
South African ◽  
Gay Couples ◽  
Core Category ◽  
Picket Fence ◽  
Open Relationship ◽  
The Individual ◽  
The Relationship ◽  
Porous Boundaries

Many gay couples engage in nonmonogamous relationships. Ideas about nonmonogamy have historically been theorised as individual pathology and indicating relational distress. Unlike mixed-sex couples, boundaries for gay couples are often not determined by sexual exclusivity. These relationships are built along a continuum of open and closed, and sexual exclusivity agreements are not restricted to binaries, thus requiring innovation and re-evaluation. Three white South African gay couples were each jointly interviewed about their open relationship, specifically about how this is negotiated. In contrast to research that uses the individual to investigate this topic, this study recruited dyads. The couples recalled the initial endorsement of heteronormative romantic constructions, after which they shifted to psychological restructuring. The dyad, domesticated through the stock image of a white picket fence, moved to a renewed arrangement, protected by “rules” and imperatives. Abbreviated grounded theory strategies led to a core category, “co-creating porous boundaries”, and two themes. First, the couple jointly made heteronormative ideals porous and, second, they reconfigured the relationship through dyadic protection. The overall relationship ideology associated with the white picket fence remained intact despite the micro-innovations through which the original heteronormative patterning was reconfigured.

scholarly journals The Influence of Government Effectiveness and Corruption on the High Levels of Homicide in Latin America

2021 ◽  
Vol 10 (5) ◽  
pp. 172
Author(s):  
Spencer P. Chainey ◽  
Gonzalo Croci ◽  
Laura Juliana Rodriguez Forero
Keyword(s):  
Economic Development ◽  
Latin America ◽  
Latin American ◽  
International Variation ◽  
Government Effectiveness ◽  
Latin American Region ◽  
Socio Economic Development ◽  
Structural Variables ◽  
The Relationship ◽  
Latin America Region

Most research that has examined the international variation in homicide levels has focused on structural variables, with the suggestion that socio-economic development operates as a cure for violence. In Latin America, development has occurred, but high homicide levels remain, suggesting the involvement of other influencing factors. We posit that government effectiveness and corruption control may contribute to explaining the variation in homicide levels, and in particular in the Latin America region. Our results show that social and economic structural variables are useful but are not conclusive in explaining the variation in homicide levels and that the relationship between homicide, government effectiveness, and corruption control was significant and highly pronounced for countries in the Latin American region. The findings highlight the importance of supporting institutions in improving their effectiveness in Latin America so that reductions in homicide (and improvements in citizen security in general) can be achieved.

scholarly journals Soil Nutrient and Vegetation Diversity Patterns of Alpine Wetlands on the Qinghai-Tibetan Plateau

2021 ◽  
Vol 13 (11) ◽  
pp. 6221
Author(s):  
Muyuan Ma ◽  
Yaojun Zhu ◽  
Yuanyun Wei ◽  
Nana Zhao
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Soil Properties ◽  
Soil Ph ◽  
Plant Biomass ◽  
Principal Component ◽  
Vegetation Diversity ◽  
Vegetation Biomass ◽  
Relative Contribution ◽  
The Relationship

To predict the consequences of environmental change on the biodiversity of alpine wetlands, it is necessary to understand the relationship between soil properties and vegetation biodiversity. In this study, we investigated spatial patterns of aboveground vegetation biomass, cover, species diversity, and their relationships with soil properties in the alpine wetlands of the Gannan Tibetan Autonomous Prefecture of on the Qinghai-Tibetan Plateau, China. Furthermore, the relative contribution of soil properties to vegetation biomass, cover, and species diversity were compared using principal component analysis and multiple regression analysis. Generally, the relationship between plant biomass, coverage, diversity, and soil nutrients was linear or unimodal. Soil pH, bulk density and organic carbon were also significantly correlated to plant diversity. The soil attributes differed in their relative contribution to changes in plant productivity and diversity. pH had the highest contribution to vegetation biomass and species richness, while total nitrogen was the highest contributor to vegetation cover and nitrogen–phosphorus ratio (N:P) was the highest contributor to diversity. Both vegetation productivity and diversity were closely related to soil properties, and soil pH and the N:P ratio play particularly important roles in wetland vegetation biomass, cover, and diversity.

The relationship between species diversity and functional diversity along aridity gradients in semi-arid rangeland

2021 ◽  
Vol 195 ◽  
pp. 104632
Author(s):  
Guy Dovrat ◽  
Ehud Meron ◽  
Moshe Shachak ◽  
Yosef Moshe ◽  
Yagil Osem
Keyword(s):  
Species Diversity ◽  
Functional Diversity ◽  
The Relationship ◽  
Semi Arid ◽  
Arid Rangeland

scholarly journals On the mental toughness of self-aware athletes: Evidence from competitive tennis players

2017 ◽  
Vol Volume 113 (Number 1/2) ◽  
Author(s):  
Richard G. Cowden ◽  
◽  
Keyword(s):  
South African ◽  
Multivariate Regression ◽  
Research Evidence ◽  
The Self ◽  
Mental Toughness ◽  
Self Awareness ◽  
Regression Analyses ◽  
Tennis Players ◽  
Self Reflection ◽  
The Relationship

Abstract This study examined the relationship between mental toughness (MT) and self-awareness in a sample of 175 male and 158 female South African tennis athletes (mean age = 29.09 years, s.d. = 14.00). The participants completed the Sport Mental Toughness Questionnaire and the Self-Reflection and Insight Scale to assess MT (confidence, constancy, control) and self-awareness (self-reflection and self-insight) dimensions, respectively. Linear regression indicated that self-insight (β=0.49), but not self-reflection (β=0.02), predicted global MT. Multivariate regression analyses were significant for self-reflection (ηp²=0.11) and self-insight (ηp²=0.24). Self-reflection predicted confidence and constancy (ηp²=0.05 and 0.06, respectively), whereas self-insight predicted all three MT subcomponents (ηp²=0.12 to 0.14). The findings extend prior qualitative research evidence supporting the relevance of self-awareness to the MT of competitive tennis athletes, with self-reflection and insight forming prospective routes through which athletes’ MT may be developed.

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