Wild fruit trees and shrubs of Southern Africa: Geographic distribution of species richness

1998 ◽  
Vol 52 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Eileen M. O≿brien ◽  
Charles R. Peters
Author(s):  
Yigremachew Seyoum ◽  
Demel Teketay ◽  
Girma Shumi ◽  
Melaku Wodafirash

2020 ◽  
Vol 25 ◽  
pp. 02009
Author(s):  
Davlet Mamadzhanov ◽  
Sovet Kenzhebaev

The article provides information about the form diversity and selection of walnuts in the natural walnut forests of Kyrgyzstan. In walnutfruit forests, there is a wide variety of forms of walnut and other wild fruit species. The species and intraspecific diversity of wild fruit trees and shrubs allows selecting the best forms for creating highly productive plantations in various forest conditions in order to obtain high yields of nuts and other fruits. Methods of selection and criteria for selecting the best forms of walnuts are described.


2021 ◽  
Author(s):  
Brenda Yamile Guidetti ◽  
Sebastian Dardanelli ◽  
Fátima María Lourdes Miño ◽  
Guillermo César Amico

Abstract The lack of seeds represents one of the highest difficulties to overcome for the ecological restoration of areas that have been deforested. This study evaluates the effectiveness of artificial perches in increasing the abundance and species richness of bird-dispersed seeds and the similitude of seed rain composition (origin and habit of plant seeds), of deforested areas with and without artificial perches in relation to woodland remnants that serve as seeds source. The experiment took place in two sites of the Espinal ecoregion, Argentina. We found that in deforested areas, perches increased seed abundance and species richness in the seed rain in comparison with deforested areas without artificial perches. The species composition under artificial perches was similar to the seed rain dispersed in the woodland. However, a decrease in the richness of native species was significant in the deforested area, probably due to behavioral differences between opportunistic and obligate frugivorous. Seed of trees and shrubs species were well represented in the seed rain under artificial perches. Results from this study contribute to the understanding of nucleation and recovery mechanisms used by nature that reflect ecosystem resilience. We recommend using artificial perches in deforested areas with potential for recovery because it is an efficient technique to promote the entry of birds and increase seed rain, preserving features of the original environment. However, using artificial perches should be avoided in sites with potentially invasive non-native species.


2015 ◽  
Vol 103 (4) ◽  
pp. 871-879 ◽  
Author(s):  
Simeon Bezeng Bezeng ◽  
Jonathan T. Davies ◽  
Kowiyou Yessoufou ◽  
Olivier Maurin ◽  
Michelle Van der Bank

Author(s):  
Pekka Niemelä ◽  
Heikki Roininen ◽  
Henri Vanhanen ◽  
Timo O. Veteli

Author(s):  
Kateřina Bubíková ◽  
Richard Hrivnák

Individual types of waterbodies are characterised by their specific environmental conditions controlling growth of aquatic macrophytes. We focused on effects of environmental factors on macrophyte species richness in canals, ponds, rivers and streams within Central European region. We employed generalised linear models (GLM) to assess separately overall macrophyte species data and data on wetland species (true aquatic plants and helophytes). No significant difference was revealed by comparing species richness among water body types, though canals were the richest water bodies and streams supported the lowest diversity of macrophytes. The models for all the waterbodies, except streams, contained at least two variables and the explained variability ranged from 37% to 77%. The most recurring variables were the coverage of fine substrate, turbidity, shading by bank and shore trees and shrubs, and altitude. Nevertheless, no obvious pattern of factors was observed for particular water body types. Our study confirmed that aquatic macrophyte species richness is shaped by a complexity of factors and necessity of targeting survey and further generalisation of results not only on one specific water body.


The Auk ◽  
1985 ◽  
Vol 102 (3) ◽  
pp. 556-579 ◽  
Author(s):  
Gary R. Graves

Abstract Intraspecific variation in plumage was used to test the null hypotheses that geographic variation in 280 species of elevationally restricted Andean forest birds is independent of elevation and is not a function of patchy geographic distribution. Both null hypotheses were rejected. At most taxonomic levels, geographic variation in plumage was correlated positively with both the mean of its elevational distribution and the size of its geographic range. Vertical amplitude of elevational distribution was not a significant predictor of geographic variation in plumage in most taxa. Independent of these elevational correlates, patchily distributed species showed significantly more geographic variation than continuously distributed species. These results show that geographic variation and presumably ongoing speciation phenomena are greater at higher elevations. The decreased species richness at high elevations may be attributable to a higher rate of extinction from catastrophic disturbance as well as to ecological factors that limit sympatry in newly formed species.


Sign in / Sign up

Export Citation Format

Share Document