Man was a foraging hunter–gatherer during the initial period of evolution. Later he started cultivating cereals and legumes and thus the transition from foraging to farming occurred. As a result, many of the useful wild plants have come under cultivation. Today, thousands of plant species are cultivated throughout the world for various uses. For most of those cultivated species, the wild populations exist in their natural habitats. However, there are some economically significant plants which are extinct in the wild, but survive only under cultivation due to their economical value.

As the climate warms, the carbon balance of arctic ecosystems will respond in two opposing ways: Plants will grow faster, leading to a carbon sink, while thawing permafrost will lead to decomposition and loss of soil carbon. However, thawing permafrost also releases nitrogen that fertilizes plant growth, offsetting some carbon losses. The balance of these processes determines whether these ecosystems will act as a stabilizing or destabilizing feedback to climate change.

Groundwater ha s emerged as the mainstay of irrigated agriculture in India. However, ineffective institutional arrangements for its management have resulted in both groundwater over-exploitation and wasteful use of energy. To address the dependence of groundwater use on energy, suggestions have been made to adopt solar-powered irrigation pumps. It is argued that solar pumps are not only economically unviable, but under the present policy context, their use would do little to reduce groundwater and energy use in Indian agriculture.

Given the increasingly prominent role and scope for off-grid solutions in complementing grid-based electrification in India, especially to electrify habitations where grid electricity is yet to reach, it would be crucial to set up appropriate regulatory arrangements for the scaling up of off-grid interventions in India. In view of this, the paper attempts to analyse the role of possible regulation in the off-grid electrification sector and explores the type of regulatory incentive structures that could be put in place in order to allow the off-grid sector to do well.

Modern medicine has created a dichotomy: modern medicine on the one hand, and alternative systems on the other. This paper views this dichotomy and liminality in the context of Gandhi's vision of health. It delineates the elements and structural coordinates of this alternative healthcare system, and tries to understand how, over time, a synthesis has occurred between the epistemologies of Nature Cure and Modern Medicine. It also looks at how Gandhi's vision of health has undergone a change at two levels, that of "space" and structural relations.

Exploitation of the extensive polymetallic deposits of the Andean Altiplano in South America since precolonial times has caused substantial emissions of neurotoxic lead (Pb) into the atmosphere; however, its historical significance compared to recent Pb pollution from leaded gasoline is not yet resolved. We present a comprehensive Pb emission history for the last two millennia for South America, based on a continuous, high-resolution, ice core record from Illimani glacier.

Landslides, floods, and droughts are recurring natural disasters in Nepal related to too much or too little water. The summer monsoon contributes more than 80% of annual rainfall, and rainfall spatial and inter-annual variation is very high. The Gandaki River, one of the three major rivers of Nepal and one of the major tributaries of the Ganges River, covers all agro-ecological zones in the central part of Nepal.

Maize yield is sensitive to high temperatures, and most large scale analyses have used a single, fixed sensitivity to represent this vulnerability over the course of a growing season. Field scale studies, in contrast, highlight how temperature sensitivity varies over the course of development. Here we couple United States Department of Agriculture yield and development data from 1981–2012 with weather station data to resolve temperature sensitivity according to both region and growth interval.

Investigations of climate–growth interactions can shed light on the response of forest growth to climate change and the dendroclimatic reconstructions. However, most existing studies in the climatically important Tibetan Plateau (TP) and surrouding regions focus on linear growth responses to environmental variation. Herein we investigated both the linear and the nonlinear climate–growth interactions for 152 tree-ring chronologies in the TP and vicinity.

Changes in the phenology of vegetation activity may accelerate or dampen rates of climate change by altering energy exchanges between the land surface and the atmosphere and can threaten species with synchronized life cycles. Current knowledge of long-term changes in vegetation activity is regional, or restricted to highly integrated measures of change such as net primary productivity, which mask details that are relevant for Earth system dynamics. Such details can be revealed by measuring changes in the phenology of vegetation activity.