eChapters

Forests support diverse insect communities that contribute to pollination, decomposition, nutrient cycling and other ecological processes. Certain insects, however, become destructive pests when environmental changes weaken natural regulation and favour population outbreaks. Increasing temperature, altered precipitation, drought and land-use change can affect insect development, reproduction, survival and geographical range. Climate change may also disrupt synchronization between forest trees and associated insects, intensify native-pest outbreaks and facilitate the establishment of invasive species. Such changes can reduce tree growth, increase mortality and transform forest landscapes. This chapter examines climate-related forest-pest dynamics, ecological consequences and mitigation strategies for strengthening forest health and resilience.

Population Growth
Around 1810, it took all of human history for the population to reach one billion. This quadrupled to 2 billion people in just 120 years (1930). Then, in 45 years, 4 billion (1975). From 4.4 billion in 1980 to 5.8 billion in 1997 and 7 billion now, the world’s population has increased. It is predicted that in less than 40 years, that number will double again to 11 billion. This indicates that more people than ever before are joining the group every day.
The United Nations Population Fund (UNPF) predicts that by 2025, there will be 10 billion people on Earth, and by the next century, there will be 14 billion.
Birth rates have decreased along with mortality rates, although death rates have decreased more quickly. In most affluent countries, there are approximately 1.6 births for every death, but in less developed countries, the ratio is closer to 3.3 births for every death. Every twelve years, a billion more people live on the planet.
Reasons Behind the Quick Population Growth
• A rise in the distribution and production of food.
• Gains in the field of public health
• medical technology, as well as improvements in education and living standards in many poor countries.

Abstract

Conversion of an already arid land into a desert through indiscriminate human actions magnified by droughts. Such actions include overgrazing, repeated burning, intensive farming, and stripping of vegetation for firewood. One quarter of the earth’s surface is threatened by desertification - an area of over 3.6 billion hectares. Since 1990, Six million hectares of productive land are lost every year due to land degradation. Desertification threatens the liveihoods of more than one billion people and has already made over 135 million people homeless. Desertification does not occur in linear, easily mappable patterns. Deserts advance erratically, forming patches on their borders. Areas far from natural deserts can degrade quickly to barren soil, rock, or sand through poor land management.

Introduction

Global warming directly ref lects on rising sea levels due to melting of ice caps and natural expansion of sea water as it becomes warmer. Consequently, areas adjoining the coast and wetlands could be frequently flooded and the distribution pattern of monsoon rains may alter, through more intense downpours, storms and hurricanes. The meteorological data available at the Annamalai University, for the tail end of the Cauvery river delta region of Tamil Nadu State, India, shows that the average annual rainfall during the last 10 years segment has increased by 233 mm compared to the average of the previous 10 years segment (1588 mm and 1355 mm, respectively). In contrast, annual evaporation has reduced by 453 mm (2153 mm and 1700mm, respectively) (Kathiresan, 2011). The year 1990 was the hottest year in the last century with all other five of the warmest years in the century falling within the last 22 years. This trend indicates that f lash floods in wetlands and droughts in uplands have become more frequent. Such a changing climate warrants reinforcement of climate resilience in farming to protect the livelihoods of farmers and the biodiversity. The sub-project of the National Agricultural Innovation Project implemented by Annamalai University in Tamilnadu, sponsored by ICAR has identified three types of clusters in each of the four disadvantaged districts, based on the prevailing agro-ecology viz. wetland clusters, rainfed upland clusters and coastal shore farming clusters. The constraints for farming and livelihoods in these clusters are identified as frequent floods, inundation, drought, weed problems, crop failure, and lack of diversification (Kathiresan, 2009a and Kathiresan, 2010). Farming systems that would be resilient to such climatic and farming constraints designed through rigorous institutional and on-farm experiments (Kathiresan, 2007; Kathiresan, 2009b and Kathiresan, 2012) were disseminated for adoption by the farmers in these clusters.

Plants are frequently subjected to environmental stresses such as water deficit, freezing, heat and salt stress. Soil salinity is a major problem in arid and semi- arid regions, where rainfall is insufficient to leach salt and excess of sodium ion down and out of root zone. In Asia, around 21.5 million ha of cultivable land was affected by salinity. India had 8.6 million ha of salinity affected cultivable land. It is observed that the area of salinity has been increasing in India. In Tamil Nadu, the area affected by salinity is around 6 lakh ha. Salinity affected areas are Chengalpattu, Salem, Thanjavur, Trichy, Tirunelveli, Dharmapuri and Ramanathapuram. Salinity is the most serious threats to the agriculture especially in the arid and semi-arid region. The presence of salts in the soil and their effects on the plant physiological mechanisms was major restrictive factor for agricultural productivity. Investigations on such soils have revealed that they were charged with high and abnormal soluble salt concentrations that lowered agricultural yield, limited crop distribution and even lead to extinction of certain species.

Salinity adversely affects plant growth and development, hindering seed germination, seedling growth, enzyme activity, DNA, RNA, protein synthesis and mitosis. There has been a variation in the response of plants to salinity with its growth stages according to quantity and period of exposure to salt. Salinity by competing in nutrition element absorption causes growth reduction. Primary salt injuries include metabolic disturbance and inhibition of growth and development. Secondary salt effects include nutrient deficiency and osmotic dehydration. Excessive amounts of salts, especially sodium chloride (NaCl), in the soil induce osmotic effects, leading to changes in plant metabolism. General symptoms of damage by salt stress are growth inhibition, accelerated development and senescence and death during prolonged exposure. Salt stress causes the reduction of rice yield and severe salt stress may even threaten survival.

Introduction

The state of Maharashtra now again reels under the scarcity of water. Geologically, major part of the state is covered by Deccan basaltic flows. This basaltic terrain, as such, has been labelled notorious as far as the availability of groundwater is concerned. Uncertain availability of groundwater in the terrain is due to heterogeneity in the nature of piles of basaltic flows which adversely affects the geohydrological characters of the rocks.

The area understudy is unfortunately, a part of basaltic terrain in which no storage structures like major dams or medium projects have been constructed across the existing rivers. Consequently, the irrigation in the area and domestic needs of the people solely depend on whatever water is available in the existing dug wells. The wells do not suffice the need of the people because the percolation of water in the wells is not adequate in major part.

Introduction

One of the major problems being faced by cities and towns relate to management of municipal solid waste (MSW). Waste quantities are increasing day by day due to the increasing population and the municipal authorities are not able to upgrade or scale up the facilities required for proper management of such wastes. In many cities and towns, garbage is littered on roads and foot-paths. Citizens are also not accustomed to use the available storage facilities (dust bins) set up by the authorities. At large, lack of organized system of house- to-house collection of waste has created the littering habits. By and large, hardly we can see any city/town complying with the Municipal Solid Wastes (Management and Handling) Rules, 2000 in ‘totality”. As per information provided by Central Pollution Control Board (CPCB), 1,27,486 TPD (Tons per day) municipal solid waste was generated in the country during 2011-12. Out of which, 89,334 TPD (70%) of MSW is collected and 15,881 TPD (12.45%) is processed or treated.

In spite of various measures taken towards the proper waste collection, segregation and disposal, proper waste processing units were established as per the following details as per CPCB. The waste processing technologies reported in the country are; composting, vermi composting, biogas plant, RDF- pelletisation and others. Some of the sepelletization plants are associated with power plants for generation of electricity. However, mechanical composting and vermi composting are more popular in the country.

Abstract

It has been established beyond doubt that the drainage architecture and the fluvial histories of river systems give excellent indications not only on the surficial lithology but also on the ongoing morphotectonic processes of the planet earth. Among the various drainage patterns, the ‘eyed drainage’ pattern is considered to be one of the most significant anomalies and such ‘mega eyed’ drainages interpreted from IRS-IA imagery in some of the major river systems in Tamil Nadu, Indian Peninsula, are found to signify ongoing tectonic movements in an otherwise seismically inert shield area.

Abstract

The present study has revealed that the NE-SW and WNW-ESE trending sinistral faults are very active along the Tamil Nadu coast and the same have caused considerable slope modifications along the Coleroon and Karungalar rivers which are well-manifested in the land, water and mudflat distribution pattern. Similarly, the progradation of the land in Vedaranniam nose is due to the rise of Pattukottai-Mannargudi area and the time transgressive modifications of the Vedaranniam backwater indicates the opening up of the N-S trending Pleistocene-Holocene faults.

In meteorology, temperature is always referred to as the temperature of the air unless it is stated otherwise. There will always be exchange of heat in the atmosphere from a point at high temperature to a point at lower temperature. The transfer of heat through convection and radiation is always observed in the atmosphere whereas the conduction of heat takes place near the earth’s surface.

4.1 Diffusion of Heat

Heat diffuses (spreads) at different rates through different media, the rate at which diffusion of heat takes place is called thermal diffusivity. The thermal diffusinty of of some selected materials is given below:

One can see from the above table that iron has got higher diffusivity compared to wood. Suppose one end of iron rod is kept at hot temperature, the heat spreads faster in iron rod and the other end gets warmer quicker than in the case of a wooden stick which means that the transfer of heat is quicker in bodies with higher thermal diffusivity.

Soil pollution happens when we destroy the thin layer of healthy and productive soil, which covers the earth’s surface. Most of the world’s food is produced using this resource and if we don’t protect it the world’s farmers will be unable to grow enough food to support the worlds people.
 
Healthy soil depends on bacteria, fungi, and small animals (such as worms) to break down wastes in the soil and release its nutrients which help plants grow. The over use of fertilizers and pesticides can limit the ability of soil organisms to process wastes, which in turn makes the soil less productive or in the worst case scenario useless or even poisonous. 

The word ‘social forestry’ was coined by J. C. Westoby and used in the ninth Commonwealth Forestry Conference at New Delhi in 1968. In India the term was first used by the National Commission on Agriculture, Government of India in 1976, to denote tree raising programmes to supply firewood, small timber and minor forest products to rural population. Prasad (1985) defined social forestry as forestry outside the conventional forests which primarily aims at providing continuous flow of goods and services for the benefit of people. This implies that the production of forest goods for fulfilling the needs of the local people is social forestry. Thus, conceptually it deals with the people to produce goods such as fuel, fodder, small timber, etc. to meet the needs of local community particularly the underprivileged section (Shah, 1988).

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/or animals interact. Interaction literally means influence or mutual or reciprocal action. So component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

The success of an agroforestry system relies heavily on exploitation of the component interactions. In an ideal relationship, production of trees as well as crops or grasses in combination could be comparable to their sole performance. Agroforestry could be even more advantageous if the production of associated components is increased due to influence of trees. This is possible because trees are capable of improving productivity of soil in many ways. A large number of trees are known to fix nitrogen symbiotically. Nevertheless, instances of crop inhibition in association of trees are not uncommon. Such inhibitions are primarily caused by shade effect as well as competition for below-ground resources such as nutrients and water. In some cases inhibitory effect may also result from allelochemicals secreted by some of the tree species.

Introduction

The hot arid regions of India are spread over 32 million ha (0.32 million Sq.Km.) in the state of Rajasthan (61%), Gujarat (20%), Andhra Pradesh (7%), Punjab (5%), Haryana (4%), Karanataka (3%), and Maharashtra(0.4%) which are characterized by hostile agro-climatic conditions and fragile eco-system. Out of total hot arid area of the country (India), more than 60% area falls under the state of Rajasthan which covers 12 districts viz., Jaisalmer, Barmer, Bikaner, Churu, Sikar, Jhunhjunu, Naguar, Jodhpur, Pali, Jalor, Sriganganagar, and Hanumangarh of the state. In general, the hot arid region of Rajasthan receives very low rainfall, varies from 100 mm annun^-1in north-western district of Jaisalmer to 450 mm per annum in the eastern boundaries of arid district of Rajasthan. The potential evapo-transpiration varies from 2063 mm in Jaisalmer to 1503 mm in Sikar districts of Rajasthan. The rainfall is very erratic and often experienced prolong drought. The ground water table is very deep and often brackish in nature. The extremes of temperature having severe winter during December-January with temperature as low as -4 °C and very hot summer during May-June with temperature as high as 48-50 °C is another important characteristic of the hot arid regions. The solar radiation is very high. Atmospheric vapour pressure deficit reaches as high as 30 mb during summer (May-June). The wind velocity in June is very high which leads to heavy wind erosion and formation of sand dunes. Some time strong sand storms of very high speed (60-0 km h^-1) with huge amount of sand particles also occurs. The soils are coarse textured with low silt, clay and humus content and water holding capacity is very low and infiltration rate is very high. The soil fertility is very poor having low organic carbon (0.02-0.06%).

10.1 Introduction

As one ofthe oldest and most widely used renewable energy sources, hydropower generates electricity by using the natural flow of flowing water. Streams and rivers have been used for producing mechanical energy for thousands of years. Hydroelectric power plants are located near or on water sources since they derive their power from flowing water. The amount of energy that can be released in moving water depends on the volume of the water flowing and the elevation change from one point to another, often called head. Generally, hydropower plants can produce more electricity when there is more water flow and a higher head. 

Introduction

Climate change and climatic variability are expected to reduce agricultural productivity and threaten food security of the world, particularly in developing countries. Producing enough food for the increasing population in a background of decreasing resources and a changing climate scenario, is a challenging task. Agriculture, forestry and land use change account for about 30% of greenhouse gases (GHGs) emissions. Therefore, mitigation of GHGs emission while enhancing production is another challenge in agriculture.
 
Conservation agriculture (CA), with the three core inter-linked principles of minimizing mechanical soil disturbance, enhancing organic matter cover on soil and diversification of crops, is a viable option for sustainable agriculture with an effective solution to climate change adaptation and mitigation. The principles can be integrated and applied into most of the rainfed and irrigated production systems including horticulture, agro-forestry, organic farming, rotational farming and integrated crop-livestock systems to strengthen ecological sustainability. Worldwide about 105 Mha land is under CA and the area is increasing. However countries like USA, Brazil, Argentina, Canada and Australia occupy about 90% of the area under CA. The CA, which is advocated as an alternative to the conventional production system for improving productivity and sustainability, is now adopted by many countries and agencies as a lead model for sustainable agricultural intensification.

Abstract

The Rawana landslide, located in Sirmuar district of the Shimla Himalayas, Himachal Pradesh is repeatedly active in the recent years. It is a NE-SW oriented slide with the crown in the southwest and the wider toe in the northeast resting in Giri River. During some of the sliding events emanations of heat and gases were also inferred. In order to understand the landslide phenomenon and the causative factors, and there from to evolve mitigation measures, detailed studies of the slides were under taken. The Landslide hazard zonation mapping carried out in Rawana landslide using LHEF rating based BIS method indicates that it is located in high hazard zone. The detailed studies show the complex geological, structural, morphotectonic and hydrological setting. From the studies it is surmised that the toe erosion by Giri river and the rainfall infiltration in the mid slope region are responsible for the slide. Remedial measures have been accordingly evolved.

Introduction

The area under salt-affected soils in India is estimated to be 6.73 Mha spread over a number of states across the country. This 6.73 million ha are lying barren or produce very uneconomical yields of crops due to excessive accumulation of salts. These soils are agriculturally unproductive because of the high content of soluble salts which had harmful effects on plant growth due to moisture stress and toxicity/deficiency of some of the ions and the exchangeable sodium ions in clay complex lead to the unfavorable physical conditions of for the plant growth and water movement (Bhumla 1977). Saline and sodic soils have excess concentration of either soluble or exchangeable sodium, calcium and magnesium primarily in the form of chlorides and sulphates. Salt affected areas an expected to increase with spread of waterlogging and salinity due to increase in canal irrigation, and intensive exploitation of poor quality ground waters for agriculture in non canal commands. Certain states like Rajasthan and Haryana located in the western part of the country are endowed with 84 and 62% of poor quality ground waters, respectively. Continuous use of such waters for irrigation to agricultural crops is bound to increase the problem of salinity and sodicity in India (Yadav 1989; Minhas and Bajwa 2001). Introduction of irrigation without making proper provision for drainage is the major cause for the development of salinity in canal commands.It is severe on irrigated lands of the dry zone. It reduces crop yield and in severe cases causes complete abandonment of agriculture (Joshi and Dhir 1989; Joshi et al. 2000; Mahesh Kumar et al. 2016). The present paper deals with extent, causes, characteristics and management options of these soils for sustainability of agriculture in the area.

Introduction

In India out of the total 142 million ha of arable land around 67 per cent of them are affected by some form of land degradation due to development of salinity/sodicity or acidification, erosion by water or wind or chemical contamination. Frequent use of tillage operation under conventional cultivation system particularly in rolling terrain is one of the major causes of land degradation through accelerated water and wind erosion. The basic purpose of primary tillage operations are to control weeds, increase the availability of nutrient to plant through accelerated mineralization of organic matter, and to keep the field clean and pulverized for ease of sowing of the next crop. However the bare and pulverized top soil made them vulnerable to accelerated soil loss through runoff and also to erosion loss of soil by wind in drier agro-climatic regions. Besides soil loss, conventional tillage operation breaks the soil aggregates and exposes the soil organic carbon locked inside the aggregates to accelerated microbial degradation and thus results in net loss of organic carbon from the arable ecosystem.

Abstract

The landslides that swallowed the whole of Malin village, Maharashtra on the early morning hours of 30 July, 2014 is one of the major disasters, next only to Kedarnath episode in the recent years. Consequently, the Department of Science and Technology, New Delhi, constituted an expert committee comprising the authors of the article which made a visit and took the on the spot assessment of the disaster. Their observations show that the area is covered by the Deccan basalts, which are layered with compact and vesicular basalts; fractured and jointed basalts due to tectonics and the cooling of the basalts; and have also undergone extensive geomorphic evolution. Due to such geologic/geomorphic setting, the flow layered basaltic hillock in which Malin is located is naturally benched, which is further being leveled for the agriculture purposes. The deforestation, leveling of the hills, excessive usage of water for irrigation and the lack of drainages outlet in such benched and leveled slopes have assigned high degree of landslide vulnerability to the area. Over this, when torrential rainfall occurred in the last week of July, the landslide was triggered. On the basis such inferences, some mitigation measures have been evolved after the visit.