Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their...

The relationship between ants and their habitats was examined in oak-dominated mixed forests in the central Appalachian mountains. Ants were sampled using pitfall traps over the summers of 1995, 1996, and 1997. Principal component and correlation analysis indicated that ant diversity (ShannonÕs H ), species richness, and abundance were closely correlated with habitat principal components. Fewer...

One of the most important natural factors and critical facilities in Tehran is presence of AlborzSlopes River-Valleys which have been considered as natural tourist places for citizens since a long time ago, especiallyin hot summers and play effective role in creating a balance between manmade and natural spaces. Importance ofthese river-valleys as ecological pathways is enhanced with the increa...

The valleys of Restelica and Vraca in Kosovo have not been explored sufficiently due to their geographical position the harshness terrain. plant species Ranunculus degenii has collected Restelica, on way border with North Macedonia or between this road Albanian near Shishtavec, while Verbascum scardicola found valley. These localities are mainly dominated by silicate substrate, although presenc...

tehran city has been subject of critical environmental challenges during the course of 20th. century namely: massive population growth, broad expansion, reduction in urban open/green spaces, increasing in energy consumption and waste production. releasing industrial wastewater into river valleys have led to considerable changes in structure of city's natural landscape. the natural structur...

intra-city natural structures have always had a key role in creating sustainable urban greenspaces. adapting to natural features and relating the intra-city greenspaces to such natural structures as river-valleys, hillsides, lakes and forests, guarantee the endurance, sustainability and longevity of the natural quality of city. this paper looks at intra-city natural structures which have underg...

Remote sensing and field evidence are used to describe sand deposits found in associated pathways of emplacement in the eastern Mojave Desert. Two separate pathways are identified here: one extending eastward from the Bristol Playa through the Cadiz and Danby Playas and Rice Valley to the Colorado River, and a second parallel path extending eastward from Dale Playa through the Palen and Ford Pl...

Located in northern Taiwan, Taipei is a metropolis surrounded by hills and mountains that form a basin in which two river valleys funnel the surface airflow of this basin to the open sea. Because of the southwest monsoon, summer is a dry season in northern Taiwan but is the season of maximum rainfall in the Taipei basin. This unusual summer rainfall maximum in Taipei is largely produced by afte...

[1] Previous observational studies have identified three different types of diurnal precipitation variation over the conterminous U.S.: localized afternoon rainfall maxima over the Mississippi and Ohio valleys, propagating mesoscale convective systems (MCSs) from the Rocky Mountain region, and propagating MCSs over the Appalachian Mountains. This study focuses on the second type, which involves...

We investigate the surface widthW of solid-on-solid surfaces in the vicinity of the roughening temperature Tr. Above Tr, W 2 is expected to diverge with the system size L like lnL. However, close to Tr a clean lnL behavior can only be seen on extremely large lattices. Starting from the Kosterlitz-Thouless renormalization group, we derive an improved formula that describes the small L behavior o...