Biscutella raphanifolia is a species distributed in N Algeria and Tunisia, characterized by the presence of large, lyrate basal leaves, amplexicaul cauline leaves, and paniculate-branched inflorescences. It has been traditionally considered the only perennial taxon from B. sect. Biscutella, lifespan being the strongest argument used to differentiate B. raphanifolia from other annual taxa such a...

Plantation agriculture is more than 400 years old and contributes to the regional and national economies in many tropical countries. This paper reviews some of the main environmental issues related to plantation agriculture with perennial crops, including soil erosion, soil fertility decline, pollution, carbon sequestration and biodiversity. Soil erosion and soil fertility decline are of concer...

This paper examines the effect of conflict on agricultural production of small-farmers. First, we develop an intertemporal model of agricultural production in which the impact of conflict is transmitted through two channels: violent shocks and uncertainty brought by conflict. The model shows how conflict induces sub-optimal agricultural decisions in terms of land use and investment. We test the...

We evaluated the effect of polyacrylate polymers as immobilizing agents to aid phytostabilization of two mine soils. One soil had a very low pH (3.7) and a large Pb content, while the other was less acidic but had a greater content of Cu and Zn. Growth of perennial ryegrass (Lolium perenne L. cv. Victorian) was stimulated in polymer-amended soils. After ryegrass had been growing for 35 days, th...

Restoration treatments are based on the largely untested notion that desired recovery of plant communities following disturbance wouldn’t occur in the absence of active intervention. We identified rate of short-term (10 year) floristic changes following removal of plant functional groups in Wyoming big sagebrush plant communities in 1999e2005 and 2008. Treatments imposed on 6 6 m plots were: 1)...