scholarly journals Woody neotropical streetscapes: a case study of tree and shrub species richness and composition in Xalapa

2016 ◽  
Vol 22 (1) ◽  
Author(s):  
Ina Falfán ◽  
Ian MacGregor-Fors
Keyword(s):  
Species Richness ◽  
Shrub Species ◽  
Cupressus Lusitanica ◽  
Ficus Benjamina ◽  
Hibiscus Rosa Sinensis ◽  
Buxus Microphylla ◽  
Bougainvillea Glabra

El proceso de urbanización va más allá del remplazo de sistemas preexistentes, transformando el terreno de tal forma que representa amenazas ecológicas preocupantes. En estos nuevos sistemas, la vegetación original es removida o remplazada con una combinación de especies nativas y exóticas. Este trabajo se enfocó en generar una lista de especies actualizada de los árboles y arbustos del paisaje urbano de Xalapa (Veracruz, México), describiendo la proporción de especies nativas y exóticas. Para ello, se utilizó un enfoque de ciudad completa comprendida por una retícula de 106 sitios de muestreo. Se registró un total de 140 especies de árboles y arbustos, de los cuales 32 no habían sido registrados anteriormente para la ciudad. Las especies exóticas representaron más de la mitad de las especies registradas, las cuales en conjunto con las especies nativas estuvieron distribuidas de forma desigual a lo largo y ancho de la ciudad. Las especies más frecuentes fueron: laurel de la India (Ficus benjamina), tulipán chino (Hibiscus rosa-sinensis), buganvilia (Bougainvillea glabra), azalea (Rhododendron sp.), cedro blanco (Cupressus lusitanica) y boj de hoja pequeña (Buxus microphylla). Es notable que los sitios en los que no se registró ninguna especie de árbol o arbusto estuvieron localizados cerca del centro histórico de la ciudad, así como en sus periferias. Los resultados de este trabajo deben ser considerados cuidadosamente, ya que la distribución desigual de la diversidad de plantas en áreas urbanas puede comprometer los beneficios que provee la vegetación a los habitantes, así como sus funciones ecológicas.

scholarly journals Species richness and conservation gap analysis of karst areas: A case study of vascular plants from Guizhou, China

2018 ◽  
Vol 16 ◽  
pp. e00460 ◽  
Author(s):  
Bo Liu ◽  
Mei Zhang ◽  
W. Rainer Bussmann ◽  
Hui-ming Liu ◽  
Ying-ying Liu ◽  
...  
Keyword(s):  
Species Richness ◽  
Vascular Plants ◽  
Gap Analysis ◽  
Karst Areas

Powerline easements through forests: a case study of impacts on avifauna

1998 ◽  
Vol 4 (1) ◽  
pp. 79 ◽  
Author(s):  
Jack Baker ◽  
Ross L. Goldingay ◽  
Robert J. Whelan
Keyword(s):  
Species Richness ◽  
Bird Community ◽  
Forest Habitat ◽  
Bird Abundance ◽  
Point Counts ◽  
Southeastern Australia ◽  
Total Species Richness ◽  
New Type ◽  
Forest Values

Powerline easements are typically a strip cleared of trees and tall vegetation to a width of approximately 50 m. They may affect avifauna by modification and fragmentation of forest habitat. We investigated the responses of the bird community to easements at three sites in southeastern Australia using 25 m radius point-counts spaced at 50 m intervals from the easement to 300 m inside the forest. The easements caused an absolute loss of habitat for forest avifauna, with abundance and species richness at the easement less than 20% of the forest values. Four species of easement opportunist and one easement specialist provided evidence that the easement represented a new type of habitat for avifauna. A barrier effect of fragmentation may occur for four species of easement avoiders. These were small to medium-sized terrestrial birds associated with dense ground and/or understorey cover. The edge effect of fragmentation was an adverse impact on forest avifauna. At the margin (25?125 m from the easement) of the forest, bird abundance, mean species richness and total species richness were significantly less than the corresponding values for the interior (225?325 m) of the forest. The mean abundance at the sites varied from 13.0?17.7 birds/ha and the species richness varied significantly among sites. The adverse impacts of powerline easements on native avifauna could be minimized by site-specific management which includes strategies to minimize the loss of forest habitat and to ameliorate the effects of fragmentation.

Fish population size, and not density, as the determining factor of parasite infection: a case study

Parasitology ◽  
2004 ◽  
Vol 128 (3) ◽  
pp. 305-313 ◽  
Author(s):  
A. M. BAGGE ◽  
R. POULIN ◽  
E. T. VALTONEN
Keyword(s):  
Species Richness ◽  
Population Density ◽  
Population Size ◽  
Fish Population ◽  
Host Population ◽  
Fish Length ◽  
Total Fish ◽  
Infection Parameters ◽  
The Mean

The diversity and abundance of parasites vary widely among populations of the same host species. These infection parameters are, to some extent, determined by characteristics of the host population or of its habitat. Recent studies have supported predictions derived from epidemiological models regarding the influence of host population density: parasite abundance and parasite species richness are expected to increase with increasing host population density, at least for directly transmitted parasites. Here, we test this prediction using a natural system in which populations of the crucian carp, Carassius carassius (L.), occur alone, with no other fish species, in a series of 9 isolated ponds in Finland. The ectoparasite communities in these fish populations consist of only 4 species of monogeneans (Dactylogyrus formosus, D. wegeneri, D. intermedius and Gyrodactylus carassii); the total and relative abundance of these 4 species varies among ponds, with one or two of the species missing from certain ponds. Across ponds, only one factor, total fish population size, explained a significant portion of the variance in both the mean number of monogenean species per fish and the mean total abundance of monogenean individual per fish. In contrast, fish population density did not influence either monogenean abundance or species richness, and neither did any of the other variables investigated (mean fish length per pond, number of fish examined per pond, distance to the nearest lake, and several water quality measures). In our system, proximity among fish individuals (i.e. host population density) may not be relevant to the proliferation of monogeneans; instead, the overall availability of host individuals in the host population appeared to be the main constraint limiting parasite population growth.

scholarly journals Urbanization may reduce the risk of frost damage to spring flowers: A case study of two shrub species in South Korea

PLoS ONE ◽  
2018 ◽  
Vol 13 (2) ◽  
pp. e0191428 ◽  
Author(s):  
Hyeon-Ju Gim ◽  
Chang-Hoi Ho ◽  
Jinwon Kim ◽  
Eun Ju Lee
Keyword(s):  
South Korea ◽  
Frost Damage ◽  
Shrub Species

Species richness, environmental heterogeneity and area: a case study based on land snails in Skyros archipelago (Aegean Sea, Greece)

2005 ◽  
Vol 32 (10) ◽  
pp. 1727-1735 ◽  
Author(s):  
K. A. Triantis ◽  
M. Mylonas ◽  
M. D. Weiser ◽  
K. Lika ◽  
K. Vardinoyannis
Keyword(s):  
Species Richness ◽  
Environmental Heterogeneity ◽  
Aegean Sea ◽  
Land Snails

scholarly journals Woody flora of Uruguay: inventory and implication within the Pampean region

2012 ◽  
Vol 26 (3) ◽  
pp. 537-552 ◽  
Author(s):  
Federico Haretche ◽  
Patricia Mai ◽  
Alejandro Brazeiro
Keyword(s):  
Species Richness ◽  
National Level ◽  
Similarity Index ◽  
Rio Grande Do Sul ◽  
Shrub Species ◽  
Future Studies ◽  
Adequate Knowledge ◽  
Pampean Region ◽  
Entre Rios ◽  
Available Information

Adequate knowledge of a flora is fundamental for furthering research in several disciplines. In this context, our work arises from the necessity to update and improve available information on the native woody flora of Uruguay. The goals of this study were to objectively determine the Uruguayan native woody flora (shrub and trees), to evaluate its inventory completeness, and to explore its similarity with neighboring regions. By analyzing the Uruguayan flora we produced working definitions of shrubs and trees, and obtained a list of 313 species (57 families, 125 genera). Using 7418 distribution records, we generated cumulative species richness curves to estimate maximum species richness at national and local scales. We conclude that the completeness at the national level is high (89-95%), but at the local scale is lower and quite heterogeneous. There are still large areas without data or with little information. We found that comparatively, the similarity between Uruguayan tree species and the Province of Entre Ríos (Argentina) was high, while similarity with the Province of Buenos Aires (Argentina) was medium, and with Rio Grande do Sul (Brazil) was low. In conclusion, richness of tree and shrub species of the Uruguayan flora is greater than expected for a grassland region, and the differences found in the similarity index with the neighboring woody floras will stimulate future studies to reevaluate phytogeographic schemes of the region.

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