eChapters

Healthcare programs across many countries, particularly in developing nations, increasingly employ Behavior Change Communication (BCC) to enhance the health status and well-being of populations. BCC is a process designed to motivate individuals to adopt and maintain healthy behaviors and lifestyles. An effective BCC strategy plays a crucial role in implementing activities aimed at improving population health. Notably, BCC is a healthcare education strategy outlined in the Uttar Pradesh National Rural Health Mission (NRHM) with goals including reducing mortality, fertility, and morbidity.

Upon completion of this unit, learners should be able to:

• Explain the meaning and benefits of BCC in family healthcare.

• Discuss various channels of BCC.

• Formulate BCC strategies.

• Follow guidelines for successful BCC implementation.

Communication, as a fundamental aspect of human existence, has evolved significantly over time. Initially, it was primarily visual and verbal, but with the development of written scripts and digital technologies, these too became integral components of human interaction. Language has always been inherently complex, with individuals from different cultural backgrounds and belief systems encoding and decoding messages in diverse ways. This process involves giving meaning to and deriving meaning from various forms of communication.

Moreover, the medium through which communication occurs often imposes its own structural rules or "grammar." For instance, messages conveyed through audiovisual media or computer-mediated communication are often organized differently than those in traditional written or spoken forms. These structural differences can lead to variations in meaning depending on the context in which the communication takes place.

The recent social, political, and economic challenges worldwide necessitate the adoption of new strategies by governments and development agencies to enhance people's livelihoods. These challenges underscore the importance of understanding and appreciating the growing significance of livelihood issues, particularly sustainable livelihood mechanisms. Addressing issues such as poverty, hunger, food security, gender equality, and economic growth—which are central to the Sustainable Development Goals (SDG 17)—requires a comprehensive understanding of the complex nature of livelihood challenges, livelihood diversification, and sustainable livelihood strategies.

Governments and non-governmental organizations, especially in developing nations, are under increasing pressure to develop coordinated strategies and interventions aimed at livelihood diversification. These efforts are crucial to sustainably improve the livelihoods of the poor, disadvantaged, vulnerable, and excluded populations.

Extension workers are required to visit farm homes as a fundamental aspect of effective Extension work. These visits are essential for building trust and securing the cooperation and friendship of farm families, especially in areas where the value of educational programs is not fully understood, where group meetings are uncommon, or where cultural norms prevent women from meeting publicly. As an Extension worker, reaching all members of the community involves employing various methods. While individual visits may not reach as many people as other approaches, there are occasions where only a personal visit will suffice. Words can be misunderstood, but a friendly smile, genuine empathy, or practical assistance are universally understood. It is crucial for Extension workers to be liked by families, as this acceptance is necessary for the families to accept their recommendations. Establishing rapport takes time; understanding local customs and observing social niceties during visits can significantly impact their success. For example, sharing tea with a family can be a critical gesture.

The diffusion of need-based appropriate technologies involves strategically promoting and implementing innovations that meet the specific needs of a community. Utilizing various interactive and engaging techniques such as methods demonstration, group discussion, role play, and exhibitions can significantly enhance the effectiveness of this process.

A demonstration is an educational technique that involves showing or presenting a process, product, or concept in action to an audience. The primary goal of a demonstration is to provide a clear, practical example that enhances understanding and encourages the adoption of new practices or technologies. Demonstrations are often used in educational, training, and outreach programs to effectively convey information and skills.

Sustainability is one of the main guiding principles for our modern societies. Water and sustainable development are closely linked since the provision of water is sufficient quantities and of high quality have important impacts on our environment, society and industry as well as the well-being of next generation.

Nowadays, there are several emerging problems and risk that affects the sustainable management of water resources. Pollution diffusion pose major threat. Water resources and demand for water remain unbalanced at various levels. Groundwater abstraction and over exploitation have serious environmental impacts. Reservoirs for water storage, flood control, recreation and energy production remain controversial. Climate change on the other hand is creating lot of impact on both water availability and water demand. These problems have not only physical, chemical, biological and ecological dimensions but encompass also important socio-economic issues such as, regulatory framework for water resources management, methods to balance conflicting human and ecosystem demand, financial sustainability of water management system. This shows the complexity water managers face for sustainable management of water resources and the need to shift from strong traditional, local and regional water resources management approaches to more integrated river basin approaches dealing with uncertainties in environmental conditions, societal development and global change.

Aristotle (384 to 322 BC), an ancient Greek philosopher and scientist (Fig. 1.1) developed the concept of meteorology as a study of the lower atmosphere. Over the years meteorology developed as a science of atmosphere which deals with the physics, dynamics and chemistry of the atmosphere and their effect upon the earth’s surface, oceans and thereby life in general either directly or indirectly.

As the atmospheric conditions change from time to time in a given area and from place to place in a given time, climatology was developed as a science which studies the average conditions of the weather and its variability over a long period of time.

All most all the human activities are greatly influenced by the weather and climate to a greater extent. Therefore, the scope of meteorology encompasses various activities which are of considerable economic significance as detailed here below;

1.1 Housing

The design and construction of houses, buildings, industrial structures etc. depends upon the weather and climate of the region. Orientation of doors, windows roofs of the buildings are usually designed to provide maximum comfort and convenience to the people.

Air is one of the primary things that make life on earth possible. The earth’s atmosphere or air is made up of variety of gases and other particles. The dynamic layer surrounding the earth’s surface containing various mixture of gases, moisture and solid particles (aerosols) is called atmosphere. The atmosphere is generally defined as the gaseous envelop surrounding the earth.

The formation of the earth was believed to be about five billion years ago. In the first 500 million years, a thick atmosphere emerged from the vapour and gases that were expelled from the interior of the earth. Hydrogen (H2 ), water vapour, methane and carbon dioxide were some of the gases believed to be initially formed in the atmosphere due to out gassing from the interior of the earth. About 3.5 billion years ago, the atmosphere consisted of carbon dioxide (CO2 ), Carbon monoxide (CO), water vapour (H2 O), nitrogen (N2 ) and hydrogen present in atmospheric layers like troposphere, stratosphere, mesosphere, thermosphere (Fig. 2.1). The condensation of water vapour into water led to the formation of oceans in which sedimentation occurred and the hydrosphere was created. In the initial and ancient environment, oxygen was not present. Anaerobic is technical word which literally means without air (where air is generally used to mean oxygen and aerobic indicates the presence of oxygen). Evidence of such an anaerobic reducing atmosphere was hidden in early rock formations such as iron and uranium in their reduced states.

Three fundamental processes that are responsible for inducing changes in weather are transfer of heat, energy and mass. The Sun, whose inter-surface temperature is estimated to be around 6000°C emits heat energy in the form of solar radiation which is received at the earth’s surface after it is partly depleted in the atmosphere. Therefore, it is essential to understand the processes that govern the transfer of heat in the earth-atmosphere system.

3.1 Conduction

The transfer of heat from one point to another point within the material medium without the actual movement of the particles in the medium is called conduction i.e. the heat energy transfer is conducted by the particles in the medium from hot end to cold end. If a metal rod is heated at one end, the other end of rod becomes hot gradually due to transfer of heat by conduction. In the earth atmosphere system, conduction of heat is observed at the ground surface only. The amount of heat energy transferred due to conduction (Q) is

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.

The mass of a body is usually defined as the material content of the body whereas the weight of the body is defined as the force with which the body is attracted towards the earth due to gravity. Therefore, the weight of a body is the product of its mass and acceleration due to gravity. The air in the atmosphere, which is a mixture of several gases has certain mass and although not very dense, will acquire some weight due to gravitational force of attraction when the entire column of the atmosphere from the ground level to the top of it is considered. Pressure is defined as the force for unit area. Therefore, the atmospheric pressure is defined as the force exerted by an air column of units area of cross section extending from earth’s surface to the top of atmosphere. As we go up in the atmosphere the height of the air column decreases, the air also become rarer and the atmospheric pressure decreases with increase in height.

Clouds play very important role on weather and climate. The formation of clouds takes place when water condenses in the sky. Clouds are visible accumulation of tiny water droplets and ice crystals in the Earth’s atmosphere. The moisture is always present in the atmosphere though it may not be visible. Clouds form when air becomes cooler until the water vapour present in it condenses to liquid form. The condensation over oceans occurs around solid particles like salt, dust, smoke etc. suspended in the atmosphere. The type of clouds depends upon temperature and wind. The clouds are classified based on physical appearance and the height at which clouds are formed (Fig. 7.1).

Clouds play very important role on weather and climate. The formation of clouds takes place when water condenses in the sky. Clouds are visible accumulation of tiny water droplets and ice crystals in the Earth’s atmosphere. The moisture is always present in the atmosphere though it may not be visible. Clouds form when air becomes cooler until the water vapour present in it condenses to liquid form. The condensation over oceans occurs around solid particles like salt, dust, smoke etc. suspended in the atmosphere. The type of clouds depends upon temperature and wind. The clouds are classified based on physical appearance and the height at which clouds are formed (Fig. 7.1).

The general circulation of the atmosphere explains the formation of pressure belts and wind systems in the earth’s atmosphere. It is known that the earth receives more solar radiation near the equator and gets heated more. Consequently, the air gets heated more and rises vertically upwards. As there is more convection of the air near the equator, the atmospheric pressure will be less. The warm air which moves upwards up to a height about 14 km near the equator gets cooled and move towards the poles.

The upper air gets gradually cooled when it reaches a latitude of 30°N in the northern hemisphere and 30°S in the southern hemisphere. At about 30°latitude the cold air descends to the earth’s surface. Some of the cold air after descending to earth’s surface moves towards the equator. The circulation of air between the equator and 30°N or 30°S latitudes is called Hadley cells (Fig. 8.1).

The winds blowing from 30° latitude towards the equator at surface level are called trade winds. These trade winds which move towards the equator in both northern hemisphere and southern hemisphere converge near the equator and the zone of the convergence of these winds is called Inter Tropical Zone of Convergence. As the convergence of air takes place, due to convection of heat as a result of high temperatures leads to vertical lifting of moist air. Therefore, the Equatorial regions receive more rainfall and there are tropical forests in this region.

The division of earth’s climates into worldwide system of contiguous regions, each one of which is defined by relative homogeneity of the climatic elements (Fig. 9.1)

9.1 Koppen’s Classification

Koppen’s climatic classification describes 5 major groups of climate A, B, C, D and E which are sub-divided into a total of 14 individual climate types, along with a special category of Highland (H) climate.

A - Tropical: Average temperature of coldest month is 18°C or more.

B - Dry climate: Potential evapotranspiration exceeds precipitation.

C - Warm temperature: The average temperature of the coldest month (of the middle latitudes) is higher than -3°C but below 18°C.

Drought is a situation when the demand for water is much greater than the availability of water. Drought is a creeping phenomenon and it is experienced only after it has set in. The scarcity of water compared to demand will have greater impact on every activity of human life including failure of crops, food shortages, decline in ground water table, drying tanks, lakes or reservoirs, acute shortage of drinking water for humans and livestock shortage for cattle etc.

Drought will have very serious impact on economy of households as well as that of nation. There are five different types of droughts depending upon the nature of shortage of water

10.1 Meteorological Drought

Meteorological drought occurs when the water received through rainfall during a given period is much less than long period average rainfall of the area. The meteorological drought is associated with either failure of rain or due to long gap between the successive rainfall events. In India, meteorological drought occurs due to failure of south west monsoon or long breaks in south west monsoon rainfall. In Tamil Nadu the drought occurs due to failure of north east monsoon rainfall during months of October to December.

Whenever the daily maximum temperature exceeds more than average values during summer season the heat wave will occur. Similarly, whenever the daily minimum temperature falls below the average values cold wave will occur. The India Meteorological department has developed the criteria to identify the occurrence the heat waves and cold waves.

11.1 Heat Waves

Heat wave is defined as the condition when the daily maximum temperature is 45ºC or more. Based on departure from normal daily maximum temperature of 40ºC onwards the heat waves are defined as follows:

The weather parameters that may occur outside India will also play a dominant role on weather conditions in India. Such weather parameters are called as global weather parameters and were found to play very important role on weather even in most parts of the world. During normal conditions in the Pacific Ocean, trade winds blow west along the equator, taking warm water from South America towards Asia. To replace that warm water, cold water rises from the depths-a process called upwelling. These global parameters are popularly known as El Ni?o, La Ni?a, Southern Oscillation, and ENSO (combination of El Ni?o and Southern Oscillation).

India is one of the unique countries in the world with great diversity in climate. The annual rainfall varies from about 180 mm in North western part of India to almost 11,777 mm at Cherrapunji in Meghalaya. For a considerable amount of time, Cherrapunji had occupied the position of wettest place in India. However, off late, observations revealed that it is Mawsynram which receives the maximum amount of annual rainfall. Hence, Mawsynram with 11,872 mm annual rainfall is the wettest place in India. Both the places-Mawsynram and Cherrapunji-are located within 16 kilometers from each other in the East Khasi Hills district of Meghalaya. The maximum temperature at Churu in western Rajasthan is 50ºC and the lowest minimum temperature at Leh in Ladakh region is as low as -35ºC. In view of such great diversity in the distribution of rainfall and temperature in the country, it is necessary to have clear understanding on regional, seasonal and diurnal variation in different weather parameters (Fig. 13.1).

According to Thornthwaite’s method of climatic classification, six major types of climates exist in India (Fig. 14.1) as stated below:

14.1 Perhumid Regions of India (A)

These regions receive rainfall of more than 2500 mm and consist of Konkan region along Western Ghats, Kerala and most parts of northeast India covering Assam, Meghalaya, Arunachal Pradesh and Tripura etc.

14.2 Humid Regions of India (B)

These regions receive annual rainfall ranging from 2000-2500 mm and are found in areas adjoining perhumid climate.

From the beginning of 18th century, the human activities started increasing gradually. Industrialization, increased use of petroleum products, deforestation, mining and increased use of chemicals have contributed to the pollution of natural resource base. The proportion of gases such as carbon dioxide, nitrous oxide, methane etc started increasing in the atmosphere and more heat is getting trapped in the atmosphere leading to rise in atmospheric temperatures (Fig. 15.1).

The changes in atmosphere temperatures have led to changes in weather patterns. This changes in weather pattern triggered extreme situations like heat wave, cold wave, severe cyclonic activity, strong winds and hail storms, f loods and droughts of greater intensity creating new records.

In meteorology, we often use some of the physical parameters to explain the physical processes taking place in the atmosphere. These parameters must have already appeared in the earlier chapters. However, these are given in this chapter to enable the readers to get acquainted once again.

16.1 Momentum

Momentum is defined as the product of mass and its velocity. In S.I. system units mass is expressed in kilograms and velocity in meters per second.

Momentum = Mass x Velocity

Units for momentum (S.I. system) = kg. m/sec

In C.G.S. System, mass is expressed in grams and velocity in cm/sec.

Units for momentum (C.G.S System) = gm.cm/sec

1.1. Introduction

Wildlife management often requires interventions to safely handle and transport animals. Chemical restraint, also known as immobilization or tranquilization, is a technique widely used to facilitate these processes (Hernandez, 2014). It involves the administration of drugs to temporarily immobilize wild animals, allowing for various procedures such as veterinary medical examinations, tagging, relocation, or rehabilitation. This chapter provides an overview of the principles, methods, drugs, and considerations involved in the chemical restraint of wild animals.

It has been often stated that the most important techniques required by the zoo veterinarian are those used in the capture and restraint of the patient. These techniques have developed into a highly technical science (Clarke et al., 2014). In the early days of zoos, the only practical method was to manually catch and hold the patient. Modern techniques, however, permit a veterinarian to shoot a CO2 powered gun, which discharges a projectile syringe at an animal resulting in complete immobilization of the animal (Jacques et al., 2009). This is accomplished without any physical contact between the patient and his captors.

2.1. Classification of Fish

Fish are incredibly diverse aquatic vertebrates. There are over 32,000 de scribed species of bony fish, over 1,100 species of cartilaginous fish, and over 100 hagfish and lampreys. Fish can be broadly classified into three groups:

2.1.1. Superclass Agnatha (Jawless fish): These are the most primitive fish, lacking jaws and paired fins. They have existed for over 500 million years. Examples include lampreys and hagfish.

2.1.2. Class Chondrichthyes (Cartilaginous fish): These fish have skeletons made of cartilage instead of bone. They have jaws and paired fins. Examples include sharks, skates, and rays.

2.1.3. Superclass Osteichthyes (Bony fish): This is the largest and most diverse group of fish. They have skeletons made of bone and have jaws and paired fins. Examples include tuna, salmon, goldfish, and many more.

3.1. Introduction

Various procedures performed on reptiles often necessitate chemical restraint or general anesthesia. Even routine tasks like physical examination and transportation can pose challenges, particularly with large or uncooperative reptilian patients. For safety reasons, venomous species are typically evaluated under chemical restraint. The respiratory anatomy and physiology of reptiles differ significantly from those of more familiar mammals, influencing their response to commonly used anesthetic agents. Historically, anesthetics recommended for reptiles had notable metabolic effects, but inhalant anesthesia has become more popular in recent times. Nonetheless, in species capable of anaerobic metabolism, induction with these agents may not be feasible (Girling 2013).

4.1. Classification

The class Aves, also known as birds, is a group of warm-blooded vertebrates characterized by feathers, toothless beaked jaws, laying hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds are found worldwide and come in a variety of sizes, from the tiny humming bird to the massive ostrich.

The classification of Aves can be broken down into two major subgroups: Palaeognathae and Neognathae.

4.1.1. Palaeognathae: Also known as ratites, these are flightless birds with f lat sterna (breastbones) that lack keels, which are important for flight muscle attachment. Examples of palaeognathae include ostriches, emus, rheas, and kiwis.

Rodents and lagomorphs are two distinct groups of mammals, often mistaken for each other due to some shared physical characteristics. However, they belong to different taxonomic orders and possess several key differences

5.1. Rodents

They belong to the order Rodentia and the example species include rats, mice, squirrels, hamsters, guinea pigs, beavers, and porcupines. Order Rodentia is the largest and most diversified mammalian group, differing widely in size, behavior, feeding habits, anatomy, and physiology. Based on the anatomy and functional differences of masseter muscles, it is divided into 3 suborders viz., Caviomorpha, Myomorpha, and Sciuromorpha. Caviomorpha is also called hystrichomorpha and includes guinea pigs, chinchillas and degu. The suborder Myomorpha includes mice, rats, hamsters and gerbils. These animals have the strongest ability to gnaw among animals in all 3 suborders. Sciuridae is a family that includes small or medium size rodents. This family consists of tree squirrels, ground or medium size squirrels, and large size squirrels also known as marmots or prairie dogs (Cynomys ludovicianus). Smaller and less bushy tailed squirrels are known as chipmunks (Tamias striatus) and flying squirrels (Glaucomys volans).

Carnivora is an order of placental mammals that have specialized in primarily eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the fifth largest order of mammals, comprising at least 279 species. They come in a very large array of different body plans with a wide diversity of shapes and sizes. The common characteristics of carnivores are given below:

• They are meat eaters.

• There is the presence of canine teeth.

• The intestinal tract is short and is adapted to rapid digestion as well as the assimilation of meat.

• All species have anal glands. Some species, like the striped skunk (Mephitis mephitis), may eject the contents of the anal gland as a defensive maneuver.

• Os penis is present in males.

• There is a lack of a clavicle which helps in the freedom of movement of the forelimb.

• Ulna is well developed.

• Toes end in claws.

7.1. Introduction

Chemical restraint of insectivores is a technique used by veterinarians and wildlife biologists to immobilize small mammals that primarily eat insects, such as shrews, moles, and hedgehogs. It is essential for performing examinations, administering medications, and conducting research on these animals.

There are several factors to consider when chemically restraining insectivores:

• Species: Different species of insectivores may have varying degrees of sensitivity to different drugs.

• Age and health: Younger and healthier animals generally tolerate chemical restraint better than older or sick animals.

• Temperature: Insectivores are sensitive to temperature regulation, so it’s crucial to maintain a stable body temperature during restraint.

8.1. Classification

The ruminants belong to the Order Artiodactyla. The families in order of Artiodactyla include Camelidae, Tragulidae, Cervidae, Giraffidae, Antliocapridae, and Bovidae.

The family Camelidae includesGuanaco (Lama guanicoe), Llama (Lama glama), Alpaca or South American camelid mammal (Lama pacos), Dromedary camel (Camelus dromedarius), and Bactrian or two-humped camels (Camelus bactrianus).

The family Tragulidae includes Chevrotains originate from Africa (Hyumo schusaquaticus) and Chevrotains that originate from Asia (Tragulus species).

The family CervidaeincludesWhite tailed deer(Odococlius virginianus), Follow deer (Dama dama), Roe-deer (Capreolus capreolus), Axis deer (Axis axis), Reindeer (Rangiter tarandus), Musk deer (Moschus species) and Chinese water deer (Hydropotes species).

9.1. Classification: Order Perissodactyla

The order Perissodactyla, also known as odd-toed ungulates, is a group of herbivorous mammals characterized by having one or three toes on each foot. They are distinguished from even-toed ungulates (Artiodactyla) by this anatomical feature. Even-toed ungulates, such as pigs, cows, and deer, have an even number of toes (two or four) on each foot. Some of the well-known members of this order include horses, zebras, asses, tapirs, and rhinoceroses.

The name “Perissodactyla” comes from the Greek words “perissos,” meaning “odd,” and “daktylos,” meaning “finger or toe,” referring to their unique foot structure. Unlike even-toed ungulates (Artiodactyla), which bear weight on their third and fourth toes, perissodactyls primarily bear weight on their third toe.

10.1. Classification of Primates

The classification of primates is a complex topic that has been revised over time as our understanding of these fascinating creatures has evolved. Here’s a breakdown of the current classification system:

10.1.1. Order: Primates

Primates are an order of mammals that includes lemurs, lorises, tarsiers, monkeys, apes, and humans. They are characterized by a number of shared features, including:

• Opposable thumbs: This allows primates to grasp objects and manipulate their environment.

• Forward-facing eyes: This provides primates with depth perception, which is important for arboreal locomotion and foraging.

• Enlarged brains: Primates have relatively large brains for their body size, which is associated with their intelligence and complex social behaviors.

• Reduced sense of smell:Compared to other mammals, primates have a weaker sense of smell. This is thought to be due to their reliance on vision for foraging and social interaction.

Agroforestry is a very old practice, dating back many years. Tropical farmers have long been growing food crops, timber, and livestock in addition to taking advantage of the variety of products that may be obtained from natural wood lots. Indian culture is deeply rooted in its appreciation of trees and forests. The forests gave birth to the greatest aspects of Indian culture. The sages who developed Hindu philosophy resided in forests, living in perfect harmony with the natural world. In fact, trees have been discussed in our ancient literature so much that people were planting trees on their own in addition to crops for agriculture. Maharishi Kashyap’s book ‘Krishishukti’ divides land into multiple categories and designates regions that are suitable for tree planting. Particular sites for planting trees include all wet and dry regions as well as the vicinity of homes, wells, and tanks. However, foresters and farmers, who have historically worked within very strict disciplinary boundaries and focused on producing their favoured commodities - crops, livestock, and trees - used to disregard such integrated production systems that incorporate many disciplines.

A scientific evaluation of the physical characteristics of the land, the properties of the soil, and the management techniques is called land capacity categorization. Understanding potentiality, capacity, and appropriateness for the best possible use of land is the primary goal of land capability categorization. Measuring land capacity provides an objective assessment for land preservation in certain ecological scenarios.

On the one hand, land capacity aids in determining if a piece of land is efficient for a certain use, and on the other, it aids in preventing inappropriate use of the land, which poses a risk of erosion and degrades the quality of the land. Therefore, in order to maximise production, each piece of land’s potential should be assessed taking into account both its pedo-geomorphic characteristics and any constraints resulting from environmental threats. Additionally, under the necessary management practices, capacity categorization allows farmers to use the land appropriately for sustainable output.

It is vital to categorise agroforestry and its many systems in accordance with certain contemporary standards in order to have a thorough grasp of them and to enable future progress. Since each agroforestry system refers to a different set of agroforestry practices involving agriculture (crops), forestry (trees), and pasture (animals), the various uses of land are combined either temporally or spatially. Each agroforestry system has its own unique arrangement of various components, such as crops, animals, perennial trees, etc., and degree of interaction between the components. In terms of structure, composition, age intensity, technology, inputs, etc., one system varies from the other.

Creating a useful framework for the synthesis and analysis of data on current systems as well as the creation of new, promising ones should be the primary goal of classification. For this reason, every categorization system needs to have the accompanying the following standards.

Farmers have been growing trees for different purposes for thousands of years. Tree species that are grown to provide more than one significant function are called multipurpose trees. These functions may be productive such as producing fuelwood, timber, fibre, fodder, food, medicine, etc. and/or protective such as soil conservation, shade, shelterbelt, microclimate amelioration, land sustainability, biodiversity preservation, etc. All trees are multipurpose; some, however, are more multipurpose than others. Tree species can be multipurpose in two ways.

1. A single tree can provide more than one function. For example, Gliricidia sepium is grown as living fences that provide fuel, fodder and green manure for agricultural crops - all at the same time.

2. Trees of the same species, when managed differently, can provide different functions. For example, Leucaena leucocephala is managed so that some trees will mainly yield wood while others mainly produce leaf fodder.

The idea of social forestry is not new in India. It may be found in Lord Buddha’s teachings from around 2500 years ago. According to Buddha’s teachings, a devout Buddhist should plant one tree and nurture it for five years so that it matures into a complete tree. By doing this, a person should plant around f ive trees over his lifetime. It is also believed that the Great Emperor Ashoka planted fruit trees and shade trees by the roadsides for the benefit of passing travellers.

The rural economy in India has been largely supported by forests. In the past, the local people kept an ecological balance while managing their woods to provide food, fuel, fibre, fodder, timber and herbal remedies. However, India’s forests have rapidly disappeared due to biotic pressure from expanding human and animal populations, a lack of technical skills, insufficient investments, and ownership changes. In addition to biotic pressure, other factors that led to the depletion of forest resources includes inadequate scientific and technical inputs; staff lacking the necessary skills and training to assume their expected new roles; poor investment in forest development; and damage from mining, irrigation projects, industries, roads; and shifting cultivation. As a result, in the early 1970s, new ideas in forestry development were introduced. Therefore, a variety of activities were incorporated in social forestry initiatives, including planting trees on agricultural bunds and roadsides, creating woodlots on shared lands, and integrating local people in the gathering, processing, and management of forest products.

Management approaches to soil, including problems of soil degradation and low soil fertility, have recently undergone major changes. The earlier concept was to concentrate on achieving high levels of production from the more fertile areas, leaving the marginal lands for extensive use only. Steeply sloping and highly drought-prone areas were mostly left without any cultivation as production from these areas was hardly cost effective. Soil constraints were to be overcome by inputs like improved crop varieties, fertilizers, chemical control of pests and diseases, and the use of irrigation.

The approach of use of newly developed high yielding crop varieties, improved agronomic management practices, use of chemical fertilizers, efficient water management and timely plant protection measures has been successful in achieving large increases in crop productivity in recent years. On the other hand, continuous application of fertilizers at higher rates leads to environmental problems. Yield responses to fertilizers have declined because of soil physical degradation and micronutrient deficiencies. Above all, large numbers of poor farmers simply can neither afford high levels of fertilizers and other purchased inputs, nor do they have the capital to take on the risk involved in their use. Increasing the area under irrigation has also run into severe constraints in the form of limits to available freshwater resources.

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.

All agroforestry systems are characterized by three basic sets of attributes; productivity, sustainability, and adoptability (Nair, 2008).

Productivity: The majority of agroforestry systems, if not all of them, strive to maintain or raise both land productivity and output (of desired commodities). In several aspects, agroforestry may raise production. These include higher yields of related crops, less input use in the cropping system, enhanced labour efficiency, and higher production of tree products.

Sustainability: Agroforestry can achieve and indefinitely maintain conservation and fertility goals by conserving the production potential of the resource base, mainly through the beneficial effects of woody perennials on soils.

Adoptability: Improved or new agroforestry technologies that are introduced into new areas should fit the social as well as environmental characteristics of the land use system for which it is designed and should also confirm to local farming system.

Agroforestry is a land use system that involves two or more plant species at least one of which must be a woody perennial. When perennial woody and herbaceous components are grown together on the same piece of land their performance would largely depend on their ability to share various growth resources in a given environmental situation. Due to difference in growth pattern and resource requirement of the components in agroforestry situation, a close interactive relation is obvious. Thus, careful management practices for the components are required to establish a successful agroforestry system. The characteristics of the trees and crops, and their interactions, can be modified with good management practices in order to take advantage of the positive characteristics and minimize the effects of the negative ones. Effective and efficient agroforestry management may be divided into two groups; tree management and agricultural crop management.

Ecology of a place is influenced by a number of biotic and abiotic factors. An agroecological zone is broadly homogeneous in climatic and edaphic factors, but not necessarily contiguous, where a specific crop exhibits roughly the same biological expression. On the other hand, the characteristics of an agroecological zone influence the crops and cropping patterns of the zone. Thus, there are considerable variations in the types and management practices of agroforestry systems being followed in different agroecological zones.

AGROFORESTRY FOR HUMID AND SUBHUMID TROPICS

Humid and subhumid tropical regions have much variation in biological, social and economic parameters. The characteristics of humid tropics include high mean annual rainfall of more than 1500 mm, dry season of less than four months in a year and mean annual temperature of more than 22°C. Rainfall usually exceeds the evapotranspiration. However, demographic pressure has caused excessive deforestation and overgrazing which developed soil related problems like low soil fertility, low organic matter, high acidity and high rainfall erosivity. The agroforestry practices designed for this region should aim for improved fallows, soil fertility improvement and conservation, food production, etc. Thus, the common agroforestry systems in this zone are taungya, homegardens, alley cropping, plantation-crop combination, windbreaks, silvipastoral systems and various intercropping systems. Shifting cultivation is a common practice in tropics which should be discouraged as it causes environmental degradation and ecological imbalance, soil erosion and soil nutrient loss.

A watershed is a geohydrological unit or all the land and water area bounded by a divide which contributes runoff to a common point. Watershed is considered to be synonymous with ‘catchment basin’ and ‘drainage basin’. In watershed management approach, development is not only confined to agricultural lands but also covers the area, starting from the highest point of the land to the outlet of the natural stream. Watershed management becomes increasingly important as a way to improve livelihood of people while conserving and regenerating their natural resources.

Watershed management is the process of creating and implementing plans, programmes and projects to sustain and enhance watershed functions that affect the plant, animal and human communities within a watershed boundary. It implies the judicious use of all the resources,i.e., land, water and vegetation in an area to prevent soil erosion, improve water availability and increase food, fodder, fuel and timber on sustained basis.

In agroforestry systems the various components like tree, crop and pasture exist in different proportions and orientations. It is difficult to find out which agroforestry system is the best suited for a given land situation. Similarly, it is to be decided which technologies are required for refinement and improvement of the existing agroforestry practices. But without sufficient knowledge of the existing system in a particular land situation, it is very difficult to set the research priorities for modification and development of this system.

Diagnosis and Design (D & D) is a systematic and objective methodology developed by International Centre for Research in Agroforestry (ICRAF) to initiate, monitor and evaluate agroforestry programmes. D & D is based on the philosophy that knowledge of the existing situation (diagnosis) is essential to plan and evaluate (design) meaningful and effective programmes in agroforestry research for development. The methodology plays a strategic role in all the phases of the agroforestry research process. D & D in agroforestry is unique and it has been specially developed for the following purposes (Raintree, 1987)

Trees have been used in cropping systems since the beginning of agriculture. Throughout the world, at one period or another in its history, it has been the practice to cultivate tree species and agricultural crops in intimate combination. In the tropics, human beings underwent a transition from hunting/gathering to the use of domesticated plants and livestock. As a part of the process, they cut down trees, cleared the debris by burning and sowed crops in the ash enriched soil. It was the ‘slash-and-burn’ agriculture, a primary forerunner of the present-day agroforestry and a practice that might have originated in the Neolithic period, around 7000 BC.

There are innumerable examples of traditional land-use practices involving combined production of trees and agricultural species on the same piece of land in many parts of the world. Trees were an integral part of these farming systems and they were deliberately retained on farmlands to support agriculture. These practices are now known as agroforestry. However, the ultimate objective of these practices was not tree production but food production.

Human societies over the ages have depleted natural resources in different ways and degraded their local environments. Indiscriminate cutting down of trees and accelerating the construction works lead to global warming and climate change. Climate scientists believe that human-induced deforestation is responsible for 18-25% of climate change. Accumulation of greenhouse gases in the lower atmosphere is the main cause of global climate change. The concentration of these gases in the earth’s atmosphere is increasing, mainly due to deforestation and the combustion of fossil fuels which release carbon dioxide.

The earth receives heat energy constantly from the sun through radiation. Some of the heat is absorbed and some is reflected. Carbon dioxide works like an invisible blanket that wraps around the earth and traps the heat inside, similar to the function of a greenhouse. A greenhouse is a structure that is used in colder climates to grow plants. Even when outside temperatures drop below freezing point, greenhouses are still warm enough inside to grow plants. Greenhouses are made of glass, which allows solar radiation to enter. The heat is trapped inside the greenhouse, allowing plants to grow all the year round. Increasing concentrations of carbon dioxide in the earth’s atmosphere insulate it like a greenhouse, leading to a gradual warming of the earth’s atmosphere. Carbon dioxide is the major greenhouse gas, but there are others as well, including methane and nitrous oxide.

Multipurpose trees and shrubs are defined as all woody perennials that are purposefully grown to provide more than one significant contribution to the production and/or service functions of a land-use system that they occupy. In agroforestry systems, different species of trees and shrubs can be planted with many types of crops in a variety of patterns. Thus, it is required to know about the methods of propagation and nursery raising, planting and other silvicultural management practices along with the diverse uses of multipurpose trees and shrubs of tropical and subtropical areas before their selection for forestry and agroforestry activities. It is important to select the most suitable tree species since it is not easy to replace them once they have been planted.

MANGIUM (Acacia mangium)

Acacia mangium is a single-stemmed evergreen tree that grows to 25-35 m in height and up to 60 cm in diameter. The bole is usually straight, often fluted near the base, free of branches for up to half its height. Mangium is native to Australia, Indonesia and Papua New Guinea. However, it tolerates varied site conditions and has adaptability to different planting objectives. Mangium shows most vigorous growth on well-drained, fertile soils in high rainfall areas in the humid tropics. It is valued for its rapid growth and has been planted throughout the humid tropics and is a major plantation species in the Asia Pacific. Provenances from Papua New Guinea consistently show better growth in height and diameter.

Plant hormone ethylene is involved in a number of physiological activities within the plant system, ranging from seed germination to fruit development. Ethylene acts as a key player in accelerating fruit ripening by regulating the activities of different enzymes, and is responsible for shortening the shelf life and associated post-harvest losses during the storage of fruit crops. However, all fruit crops have different ethylene production capacities and vary in their response to ethylene. Hence, effective management of post-harvest ethylene is imperative for addressing the global challenge of reducing fruit losses after harvesting. In recent periods, numerous technologies and compounds have been developed for the suppression of ethylene and for enhancing in-situ oxidation of ethylene or inhibiting its production at a receptor level. Among these emerging techniques, the use of sachets, fumigating agents, catalysis and composite films embedded with nanoparticles has been found to be trending, but the use of some of compounds has been limited due to health risks or consumer unacceptance. However, most of these technologies are very costly and are not affordable for marginal farmers and developing nations. In order to address these issues, long term breeding approaches for shelf-life improvement, targeting the tfs, ERFs have been involved. This manuscript fills the knowledge gap by encompassing all the recent progress made in enhancing the shelf life of fruits by managing ethylene during storage.

Fruit ripening is a phenomena during which horticulture produce undergoes a series of complex physical and biochemical changes initiated through a series of hormones (Ethylene, auxin, abscisic acid (ABA), gibberellins, jasmonic acid, etc.) to attain maximum physiological maturity and favourable organoleptic properties. These changes lead to alterations in colour, texture, aroma, flavour and nutrient composition. In a nut shell, ripening involves increase in pulp to peel ratio, solubilisation of pectic substances, degradation of complex carbohydrates, organic acids and chlorophyll, accumulation sugars, flavour volatiles, polyphenolic compounds and pigments (carotenoids, xanthophylls and anthocynanins). The extent of these changes guide harvesting, readiness for processing and consumption decisions, with physic-chemical alterations serving as indicators of optimum ripeness. Respiration rate, ethylene and ABA are key regulators of fruit ripening in climacteric and non-climacteric fruits, respectively. In climacteric fruits, ABA interacts with ethylene, influencing the synthesis of ethylene itself. Although there is ample documentation on the involvement of hormones in fruit development and ripening, our understanding of the functions of various hormones throughout growth, maturation, and specific ripening processes remains incomplete.

Calcium, anti-oxidants and certain enzymes are reported to play vital role in extending the shelf-life of harvested produce of many horticultural crops especially fruits. They help in maintenance of cell wall structure. Being an important constituent of cell wall, in the form of calcium pectate, it helps in maintenance of cell wall structure. Antioxidants are highly beneficial in extending the shelf-life of fruits besides maintaining the quality. Similarly, some enzymes play a key role in preserving the fruit quality and prolonging its market life. As some fruits are catergorized under ‘Low volume high value fruits’, it is essential to extend their shel-flife for reducing the post-harvest losses of fruits and also to reap better remuneration. Thus, it becomes indispensable to review the role of Ca, anti-oxidants and enzymes which are beneficial in keeping the harvested produce afresh for a relatively longer period.