The data presented in Table 3reveals that, Shannon index values of trees was higher on northern aspect as compared to southern aspect under agri-horticulture system. Contrary to this, the Simpson index values of trees were found to be highest on southern aspect. The higher species richness value was recorded in northern aspect. The slightly higher equitability was observed in southern aspect of agri-horticulture systems. Beta diversity was higher on southern aspect while it was lower on northern aspect of agri-horticulture system. Among the shrubs the higher diversity and species richness was ob-served in the southern aspect whereas higher Simpson Index , ebb and flow bench equitability and beta diversity was recorded in northern aspect . The tree diversity and species richness was higher on northern aspect as compared to southern aspect under agri-horticulture system whereas concentration of tree species was found to be higher on southern aspect. In contrarily the shrubs occupied higher diversity and species richness in the present study on the southern aspect under agri-horticulture system .
The diversity parameters of these agroforestry systems are comparable with the diversity indices reported by different workers for other regions in agroforestry and non-agroforestry systems . In an experiment reported the Shannon-Weaver index values from 0.41 to 2.31, concentration of dominance from 0.38 to 1.00 in the Thar desert under natural silvipastoral system which are higher than the present study. The Simpson Index for the home garden of Kerala in South India varied 0.44 to 0.86 which is quite high than the present study. In the present study, the higher diversity values on northern aspects may be due to the higher moisture con-tent and low insolation rates as compared to southern aspects, which receive the Sun rays in later part of the day, when the atmosphere is sufficiently warmed.The higher tree diversity in northern aspect was attributed to the presence of higher number of species , while the higher concentration of dominance in southern aspect, was due to the high relative proportion of few fruit species in these systems. The higher beta diversity in the southern aspect represented the higher niche diversification compared to northern aspect under agri-horticulture system.
The lower number of shrubs was found on north- ern aspect which might be due to higher slope in northern aspect under agri-horticulture systems. The tree canopy cover was higher on the northern aspect, which interrupted the growth and development of shrubs and may be another reason for the lower occurrence of shrubs. Vegetables are grown worldwide in almost 200 countries and make up a major portion of the diet of humans in many parts of the world and play a significant role in human nutrition,4x8ft rolling benches especially as sources of vitamins , minerals, dietary fiber and phytochemicals . They can be also a major source of protein for the poor. Vegetables in the daily diet have been strongly associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer . Low vegetable intake, in unbalanced diets, has been estimated to cause about 31% of ischaemic heart disease and 11% of stroke worldwide. The International Agency for Research on Cancer estimates that the preventable percentage of cancer due to such diets ranges from 5% 12% for all cancers, and 20% 30% for upper gastrointestinal tract cancers.
Some phyto-chemicals of vegetables are strong antioxidants and are thought to reduce the risk of chronic disease by protecting against free-radical damage, by modifying metabolic activation and detoxification of carcinogens, or even influencing processes that alter the course of tumor cells . “Hid-den hunger” or micronutrient and vitamin deficiencies is a pernicious problem around the world that is caused by a lack of vitamins and minerals such as vitamin A, iodine and iron in the human diet. It affects the health of be-tween 2 and 3.5 billion people in the developing world and increases the risk of illness or death from infectious diseases and children do not develop to their full physical or mental potential . In much of South Asia and sub-Saharan Africa, dietary deficiencies of iron and vitamin A are major health problems, resulting in millions of deaths each year. Iron deficiency anemia is one of the world’s most prevalent dietary deficiencies. In a recent report on the world nutrition situation, the United Nations estimated that 4 to 5 billion people are affected by iron deficiency anemia, with the most severe incidence in South Asia and sub-Saharan Africa.