eChapters

Geological evidence suggests that the age of the earth is about 4,50,00,00,000 (4.5 billion) years and life began on earth between 0.6 to 1.0 billion years after earth has formed. That is life began on earth some where 4 to 3.5 billion years ago.
The plant kingdom over the globe produce oxygen about 30,00,00,000 (3 million) kg per second which is consumed by the living beings on the earth. Air which is present in the atmosphere is a mechanical mixture of gases. The various gases, solid and liquid particles in the air that envelope the earth are bound to it by the gravitational attraction. This complex content of gases, solid and liquid particles is called atmosphere. The atmosphere extends above the surface of the earth to great heights. There is no sharp boundary between the atmosphere and the outer space. For our convenience, the height of the atmosphere is taken as 1000 km. The lowest one km which is called planetary boundary layer, contains 10 per cent of the mass of the atmosphere. All biological and human activities are confined to this planetary boundary level. The mass of the atmosphere is about 5.6 x 1018 kg (mass of earth is 6 x 1024 kg). The mass of the oceans water is about 1.4 x 1021 kg. This shows that the mass of the oceans is more than 250 times the mass of the atmosphere. The density of the dry air at the earth surface is 1.225 kg/m3 and at an altitude of 5.5 km this drops to 0.66 kg/m3 and at 30 km altitude it is about 0.013 kg/m3.

Food, clothing and housing are the three basic needs of a man. After that the additional requirement of a man are personal health and happiness. These can be considered as human factors. The material factors are agriculture, industry, trade, water resources management, insurance.

The continuous increase in population made the planners, researchers and cultivators to increase the food production to feed all the people. So, the second green revolution has to follow. Due to increase in air temperature and climate change, the cultivation practices to change based on the changing climatic condition. The study of climate is not only necessary for food production, but also needed for transportation, storage, value addition and consumption.

The need of the cloth for man is not only for style. The basic need is to protecting the human body from the climatic factors like heat and cold. Clothing must provide to maintain the body heat at about 37^oC. Clothing must be made based on the local climatic condition. So, the traditional fiber for making the cloth is better for health.

Housing provides the internal controlled climate to the human being. It provides comfort to the inhabitants. Like clothing traditional styles, sites and methods of housing have to be followed based on the climatic condition. Though people are living in the multi-storied building, they have to concentrate on comfort in the case of sufficient aeration and ventilation. In India, the Vastu Sastrum is nothing, but it provides the needs of the human livings for their comfort with sufficient light and air.

The climatic factors for a particular day are not similar to previous day. Similarly, definitely the climate of one season is not similar to other season. Man needs some recreation in the comfort climatic areas. So, he/she needs cool climate for stay that necessitate to air conditioner particularly during summer.

INTRODUCTION

Resource, land use patterns and erosion of homrgardens biodiversity have been at the core of the debate on sustainable ecosystem management today. Homegardens are considered as a resource system of multiple functions and an important wheels of vehicle for biodiversity, environmental and ecological benefits, food security (either directly food grains, fruits, vegetables and root crops or indirectly improving soil conditions and there by promoting understory crop productivity especially on degraded sites), soil conservation potential, nutritional security, socio-cultural as well as mitigation of the impact of climate change and job creation in developing and under developed countries. While increasing human population, urbanization and pressure on the earth’s ecosystems, has resulted in the breakdown of these traditional agroforestry systems, accompanied by increasing economic, cultural, nutritional, and environmental problems, there is little awareness that homegardens are under similar threats.

INTRODUCTION
 
A single teaspoon of soil has more organisms than the total number of people in this planet. Therefore measuring microbial population and their activity in soil is essential in order to measure the potential of a soil to mineralize nutrients. The rhizosphere is the biologically active zone of soil, where plant roots and microorganisms interact, and is of significant importance for plant performance as well as for nutrient cycling and ecosystem functioning (Singh et al. 2004; Marschner et al. 2004., Bhaduri et al. 2015). The structure of rhizosphere microbial communities is the result of complex interactions between plant genotype and fertilization (Aira et al. 2010).

INTRODUCTION

The latest Assessment Report (AR-5) of Intergovernmental Panel on Climate Change (IPCC) has concluded that warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The report further pointed about the warming of atmosphere and ocean; shrinking of glaciers, sea level rise and more frequent and intense extreme weather events. The most critical information pertains to the increase of the concentrations of greenhouse gases. The report figures that human influence, primarily the burning of fossil fuels, has been the “extremely likely” dominant cause of global warming over the past several decades. Based on the scientific evidences, it is reported “warming by the end of the 21st century will lead to high to very high risk of severe, widespread, and irreversible impacts globally” (Edenhofer et al. 2015).

INTRODUCTION

Biodiversity  refers to varieties of life on the Earth including  animals, plants, microbes and genes within them, their habitats and ecosystems and all variations within a given ecosystem, biome or entire planet. Biodiversity is the basis of life on Earth, important for the functioning of ecosystems, provides us with products and services without which we cannot live. Consider our food range in India. It ranges from Indian bread (chapatti), rice and rice products and related curries and other varieties made out of different vegetables. These food items are made of wheat, paddy, maize, bajra, ragi, potato, tapioca, sweet potato,  yams and corns, pulses like pigeon pea, green and black gram, Bengal gram, soyabean, vegetables like tomato, brinjal, cucumber, pumpkin, drum stick, bitter gourd, snake gourd, bottle gourd and various gourds, French bean, amaranth and  so many leafy  vegetables, spices and condiments like chilly, cardamom, ginger, turmeric, pepper, nutmeg, clove, cinnamon, cumin, coriander, fenugreek etc. This is the diversity of food we have in India. Similarly, all other groups such as herbal medicine, ornamentals, timber and non-timber species are also very diverse.

INTRODUCTION

Indigenous agroforestry systems exhibit a great intricacy with respect to their components where trees, shrubs, climbers and grasses are common. In the north-western Himalaya, farmers maintain naturally regenerating tree/shrub species, particularly on edges of terraced agriculture fields without any significant input of manpower. These systems are called as indigenous agroforestry system (Ram and Singh 1996; Vishvakarma et al. 1998, Thakur et al. 2004 and 2005). Shrubs have been meeting the fuel wood requirement of the local peasants from forest as well as village wasteland and field boundaries. Shrub dominated ecosystems extend from arctic to tropical region and occur over the entire moisture gradient from desert to wetland (Specth 1979; DI Castro 1981; West 1983). 

Introduction

Biodiversity provides enormous direct economic benefits, an array of indirect essential services through natural ecosystems, and plays a prominent role in modulating ecosystem function and stability. It provide farming systems and taxa the means to recycle nutrient, reduce insect, pest and disease problems, control weed, maintain good water and soil conditions, handle climate stresses while producing commodities necessary for human survival. It is estimated that 1400 m ha of croplands and agro-ecosystem may provide ecosystem services worth US$ 92 ha-1 per year in pollination, biological control, and food production amounting to total US $ 128 x 109 per year (Costanza 1997). Moreover, Thrupp (1997) explained several benefits provided through conservation of biodiversity (Figure 1). The animal and plant diversity and the knowledge of associated management of these resources are the assets with the farmers which are important in marginal and difficult farm conditions. Higher diversity allows greater access to available resources, and hence increased net primary production and decreased nutrient losses. Diversity management can constitute a central part of livelihood management strategies of farmers and communities in different production system (Rege et al. 2003). The multifunctional services of biodiversity in amelioration of agro-ecosystems as given in Table 1 have also been emphasized by both the Millennium Ecosystem Assessment (2005) and the International Assessment of Agricultural Science and Technology for Development (2008). 

INTRODUCTION

The entire Himalayan region is vast and its diverse geographical grouping is unique and has complex ecosystem and occupies about 18% of the total geographical area of India. Indian Himalaya (27O 50' – 37O 06' N and 72O 30' – 97O 25' E) includes the parts of trans, north-west, west, central and east Himalaya and covers approximately an area of 4,19,873 Km2 with 2500 Km length and 240 Km width. The north-western Himalayas generally represent the Himalayan tract from Kumaon in Uttar Pradesh to Chitral in Gilgit. The Himalayan ranges situated in this region exhibit a diverse climate, topography, vegetation, ecology and land use pattern. The annual average rainfall varies from 8 cm in Ladakh to over 200 cm in some parts of Himachal Pradesh and Uttar Pradesh. The vegetation may vary from the scrub in the lower hills to arctic in the Greater Himalayas. The unique physiography, climatic conditions and soil characteristics of the area has resulted in a variety of habitats and a significant biological and cultural diversity. Along the altitudinal gradient (300-800 m.a.s.l) the vegetation varies from sub-tropical, temperate, sub-alpine to alpine types. It supports about 8000 species (47.06% of the total flowering plants of India) of which 30% are endemics, 10.2% trees, 8.44% wild edibles and over 15% medicinal (Samant and Dhar 1997).

INTRODUCTION

The terms agro-forestry and farm forestry are used interchangeably in India with respect to the establishment and/or management of trees on farms for productive purposes. It also particularly recognizes the use of trees and shrubs on farms to support agricultural production, protect soil and water resources, enhance biodiversity, sequester carbon, and improve landscape values. Lundgren (1982) defined “Agroforestry as a collective name for land use systems and technologies where woody perennials are deliber-ately used on the same land unit as agricultural crops and/or animals, either in some form of spatial arrangement or temporal sequence. In agroforestry systems there are both economical and ecological interactions between the different components”. It has been proposed that including a tree component within the farming system, either on bunds and boundaries (sequentially with crops) or intercropped in an agroforestry type configuration, can lead to increased land productivity while diversifying the farming enterprise (Atta-Krah et al. 2004; Huxley 1999; Young 1989), and increase economic security for small farmers (Russell and Franzel 2004).

INTRODUCTION

The interactions of plant communities – natural or man-made, with their pests are invariably complex, and the complexity further increases with the diversity of the system. When a farmer adopts agroforestry instead of monocultures, the opportunities of relatively easy monitoring of the pest and their frequent disturbance through crop rotation, tillage and burning are traded against a greater stability of the system with an increased potential for self-regulation, which is however complex and more difficult to control. For this trade to be successful in reducing pest risks, agroforesters should not merely rely on increased diversity, but should attempt to integrate into their decisions the full range of traditional and scientific knowledge on the interactions between plant species, planting designs and management practices on one hand, and pests and their natural enemies on the other hand. This obviously requires collecting knowledge and organizing in more systematic way than up to now.

INTRODUCTION

Phytotoxin literally means “plant poison”; it may refer to any toxin produced by a plant. Phytotoxins generally have allelopathic effect. Allelo-chemicals when added/released to substratum may be directly or indirectly harmful or beneficial to the growth and development of the associated vegetation or to the source plant itself. The definition of allelopathy accepted by the International Allelopathic Society is; “any process involving secondary metabolites produced by plants, algae, bacteria and fungi that influence the growth and development of agricultural and biological systems” (Torres et al. 1996). Allelo-chemicals are defined as bio-communicators suggesting the possibility of active mixtures, because of the findings in which single compounds are not active or are not as active as a mixture (Macias et al. 1998). 

INTRODUCTION

Soil is known to harbour an array of micro-organisms. The soil micro-organisms play vital roles in the half-hidden portion of the plant i.e., the rhizosphere, where they are invariably present and are stimulated by organic substrates supplied by the plant. These are known to form the mutualistic, symbiosis with photosynthetic plants and play a key role in increasing availability of plant nutrients, the improvement of their uptake, the production of plant growth regulators, plant protection against root pathogens etc. in both natural and man-modified eco-systems.

INTRODUCTION

Himachal Pradesh, the mountainous state is well known for its natural wealth. It is situated between 300 22’ 40"to 330 12’ 40" N latitude and 750 45’ 55" to 790 04’ 20" E longitude in the western Himalayas. The 12 districts viz., Bilaspur, Chamba, Hamirpur, Kangra, Kinnaur, Kullu, Lahaul & Spiti, Mandi, Sirmaur, Shimla, Solan, and Una of the state covered 10.5 per cent of the Indian Himalayan Region (IHR) and 1.69 per cent of country’s geographic area. State experienced high variation in an elevation and climatic conditions. An elevation of the stateranged from 350 to 6975 metres above mean sea level (amsl.) that increases from west to east and south to north.On the basis of elevation and slope,the state is divided into fourdistinct topographical regions: (1) Shiwalik Hills, (2) Mountains-Lesser Himalaya, Greater Himalaya and Trans Himalaya, (3) Valleys-Shiwalik dun valleys, fluvial, and glacio-fluvial valleys, and (4) Mountain Passes (Singh and Kumar, 2014). Whereas, physiographically, state is divided into four agro-ecological zones: the Shivaliks’ low, mid and high-hills; and the cold and dry or the alpine zone (Table 1). The 70% of the state area is steep to very steep, about 19% is moderate to moderately steep, and 11% is gentle to nearly level slopes.

INTRODUCTION

Carbon dioxide gas is fundamental to sustaining life on earth for two reasons (i) it is a source of C for photosynthesis, and (ii) it acts like blanket in atmosphere that keeps the earth warm. Molecular CO₂ absorbs short wave solar radiations and release them as long wave infra red radiations. An atmospheric concentration of 300 ppm is adequate to support life on earth. CO₂ accounts for about half of the greenhouse effect. The natural concentration of green house gases (GHGs) has been essential to life on earth, creating the average temperature of 15ºC. Without the naturally occurring green house effect, the average temperature would be minus 18ºC. CO₂ concentration has now reached 400 ppm. If present trends continue then CO₂ levels would reach 600 ppm in 2100 and 1300 ppm in 2200 and level off at 1800 ppm in the year 2400 (Harvey and Danney, 2000). With increasing CO₂ concentration the amount of solar radiation absorbed by atmosphere would increase and make earth warmer. The higher atmospheric temperature can affect global hydrological cycle and alter the distribution and productivity of terrestrial biota. This can have devastating consequences for human life as each 10C increase in temperature, vegetation zones may change dramatically, moving toward the poles by 200-300 km. Further, each 1ºC of global warming will also increase water evaporation, leading to about 2% greater mean global precipitation.

INTRODUCTION

Climate change is one of the most important global environmental challenges facing humanity with implications for food production, natural ecosystems, freshwater supply, health, habitat destruction biodiversity, etc. According to the latest scientific assessment, the earth’s climate system has demonstrably changed on both global and regional scales since the pre-industrial era. Since the very beginning of civilization, land resources have been under tremendous pressure for food and forest products. Anthropogenic activities have affected the biosphere through changes in the landuse and forest management activities, thus altering the natural balance of greenhouse gases in the atmosphere. The environmental security thus, has become a serious concern across the globe. The meteorological records have shown significant increase in the environmental temperature referred to as the global warming. Human activities have increased green house gases and raised global temperature by 0.50 C over the past 100 yr, which may increase by 1.4 to 5.8°C during the next century (Bhadwal and Singh 2002). Evidence of this global crisis include the rise in global sea levels by 3.4 mm yr-1 ((http://climate. nasa.gov/vital-signs/sea-level/) through the melting of the world’s snow peaks and glaciers, which poses a threat to millions living in coastal areas. A drastic effect on splitting of huge glacier in the Antarctica has already been registered, which has thrown a challenge to save the earth, lest the very survival of the mankind will be jeopardized. Each degree rise in temperature will displace the limits of tolerance of land species some 125 km towards the poles or 150 m vertically on mountains. The Inter-governmental Panel on Climate Change (IPCC) estimates that 20 to 30 per cent of plants and animals could be at risk of extinction if average global temperatures reach the projected levels (Hawkes et al., 2000).

INTRODUCTION

Wood has been a source of fuel from time immemorial for human societies. It has been used directly as firewood and also as charcoal. The world today is energy deficient. Energy derived from fossil fuels is costly, unsustainable and its extensive use is polluting the environment. The much talked about phenomenon of ‘Global Warming’ has been ascribed to the higher accumulation of greenhouse gasses in the atmosphere released from the use of fossil fuels and also deforestation. Wood biomass is one of a range of renewable energy resources. It has an advantage over wind and solar energy, for example, as these cannot necessarily deliver power when required. Wood besides being renewable is also a clean and carbon-lean fuel and could play a valuable role in our contribution to climate change mitigation.

INTRODUCTION

Nearly 60% of the population of the country is dependent on agriculture. Rainfed agriculture supports 40% of the population and 75% of the poorest of the poor in the country (Pant 2001). Therefore, maintenance of health of production base stands as a prime goal to be achieved for sustainable production, prosperity and posterity. Tree culture is highly necessitated for amelioration of climate, soil, production of firewood, fodder, timber, fibre, fruit, gum etc. Hence, agroforestry is a viable option particularly in the Indian context.

INTRODUCTION

Medicinal and aromatic plants (MAPs) play a critical role in the healthcare provision of much of the world’s population, whether they are used to make a decoction in rural Africa, to extract an alkaloid in Switzerland or as a health food supplement in the United States. MAPs are important from several perspectives like preventive and curative treatments and are source of income to underprivileged or aboriginal people who collect these herbal plants from forests or cultivate on their field. The importance and value of traditional and indigenous herbal medicine was the subject of WHO’s campaign during the 70’s, which led to an appeal to all member countries to do their utmost to preserve their national heritage in the form of ethno-medicine and ethno-pharmacology and to re-include the use of known and tested medicinal plants and derivatives into their primary health care in rural areas, as well as an alternative when modern medicine is not available.  Out of more than 400 plants species used for production of medicine by the Indian herbal industry, fewer than 20 species are currently under cultivation in different parts of the country (Uniyal et al. 2000). According to the Department of Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homoepathy (AYUSH), India has 5,662 varieties of medicinal plants and of these trading takes place in 460, while 178 are exported in huge quantities (over 100 metric tonnes per year) and about 70 per cent of India’s population use traditional medicines derived from numerous plant species (Niraj et al. 2002; Saigal et al. 2002). It is estimated that in developing countries, about 90 per cent of medicinal and aromatic plants are harvested from wild while cultivated lands account only for 10 per cent of the total medicinal plants in active trade (Karki 2002). The increasing demand calls for cultivation of these valuable healers on commercial basis. However, the available land cannot be brought directly under MAPs cultivation. There is need to identify the landuse systems, already in practice, which may provide condition congenial for better growth and development of medicinal and aromatic plants as they are naturally getting in the wild. Tree plantations, fruit orchards and home gardens seems to be the viable option for commercial cultivation. Out of these fruit orchards could be more potential land use. Fruit trees have long gestation period of 8-10 years and till canopy development, the interspaces can be conveniently used for cultivation of medicinal and aromatic crops to get additional income. Even at later stages of orchard development trees have minimal adverse affect on the growth and yields of a number of medicinal plants grown as intercrops compared to the yields in the open (Nair et al. 1989), in some instances there may be reduction of yield of MAPs and fruit component, but the combined returns from both the components are greater than from sole cultivation. This temporal scale is even more in case of shade loving medicinal and aromatic plants. Peasants prefer fruit trees on their farms (Raintree 1992; Franzel et al. 1996) with perspective of contribution to consumption (Salam et al. 2000) and income generation (Ayuk et al. 1999; Delobel et al. 1991). Thus, these components are well thought-out to be beneficial due to low labour input and comparatively high returns round the year. This chapter presents a brief review of growth, yield and economic viability of such tree-crop combinations and further explore their potential under fruit tree based horti-medicinal agroforestry systems.

INTRODUCTION

Total forest cover in India is 70.17 million ha or 21.34% of the total geographical area according to the State of Forest Report 2015. Of this, 8.59 million ha (2.61%) is very dense forest, 31.54 million ha (9.59%) is moderately dense and rest of 30.04 million ha (9.14%) is open. The trees outside forest (TOF) are estimated to cover 9.26 million ha area which constitutes about 2.82% of the total geographical area of the country.  Thus the total forest and tree cover of the country is 24.16% of the total geographical area. The estimates of total growing stock of forest and TOF are 4.195 billion m3 and 1.573 billion m3, respectively. The total growing stock of wood in the county is estimated to be at 5.678 billion m3 which implies an average growing stock of 72.63 m3 ha-1 in 79.42 million ha of forest and tree cover (FSI 2016).