Core Paper – Iii Ecology and Plant Geography
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1st BSC BOTANY 18BBO24C - CORE PAPER – III ECOLOGY AND PLANT GEOGRAPHY UNIT – V Plant geography and forestry: Principles of plant geography – Phytogeographical regions in India. Distribution types – continuous, discontinuous and endemic. Continental drift. Vegetation mapping, GIS and its application in forestry. Vegetation types - Rain forest, Deciduous forest, Mangrove forest and Scrub jungle. Minor forest produce. Agroforestry and Social forestry. Phytogeography Topics: • Principles • History • Description of earth • Theory of tolerance • Endemism • Brief description of major terrestrial biomes (sp. Tropical, temperate and tundra) • Phytogeographical divisions of India • Vegetation of Delhi Phytogeography or plant geography deals with the geographical distribution of plants on earth. Phytogeography is defined by Good (1964) as ‘that branch of botany that deals with the spatial relationships of plants both in the present and the past’. Plant ecology + phytogeography= geobotany In systematics plants are grouped into taxa. In ecology…………………….into communities etc In phytogeography………..into phytochoria. • Phytochoria are natural floristic areas that broadly correspond to climatic types, and are based on the total number of species with the same concentric distribution pattern. • A phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phytochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap. The region of overlap is called a vegetation tension zone. • Earliest definition was given by Schouw (1823) he divided the earths surface into 25 kingdoms represented by geographical areas named after their most characteristic plants. • Eg Kingdom of Saxifrages and mosses (Alpine Arctic) • Eg Kingdom of Umbelliferae and Cruciferae (Eurasia); it was further divided into provinces. • Turrill (1959) used the term ‘realm’ instead of Kingdom. • Good divided the earth into 6 Kingdoms and 37 regions. Good (1947) floristic kingdoms HISTORTY: • Study is quite old. • Even Theophrastus gave information regarding plants in Mediterranean region. • Linnaeus and de Candolle described geographical distribution of many plants. • However the first structural approach (as a separate subject) was made by Humboldt (1817). • He is credited to be the father of phytogeography: he studied the relationship between plants and environment, both latitudinally and altitudinally. • Important contribution by Sir JD hooker too. Studied plants from different parts of the world. AIMS: • To find out and record the distribution of plants in geographical regions of the world on the basis of latitudinal and longitudinal positions. • To determine the units into which the Earth can be divided on the basis of the similarity of ranges of taxa. • To name and classify these units into phytochoria. • To determine the causes which result in these ranges. Physical geography of the earth: Layers: • Crust • Mantle (upper and lower) • Core (outer and inner) • Core (3500kms) is the densest. It is mainly metallic iron with some nickel and other elements. • Core is surrounded by mantle (2900kms). • Crust is topmost (50kms). Divided into continental (granite rock) and oceanic crust (Basalt rock) • Granite rock (light)- Silica + aluminum (sial) • Basalt rock/felsic rock (dark)- Silica + Magnesium • Granite rock is less dense than basalt hence continental platforms float over the oceanic crust. • Lithosphere includes crust and top portion of mantle. • The line of separation between crust and mantle is called MOHO or mohorovicic discontinuity (after the seismologist Andrija Mohorovicic) CONTINENTAL DRIFT THEORY Natural Vegetation and Wild life What is Natural Vegetation • Natural Vegetation are plants that would grow in an area in the absence of human influence • Different types of natural vegetation grow in different climates and soil conditions What is biome? • Very large area on land having distinct type of vegetation and animal life because of similar climatic condition Eco systEm • A BIOLOGICAL COMMUNITY OF INTERACTING LIVING THINGS AND THEIR ENVIRONMENT • IT INCLUDE • 1)BIOLOGICAL COMMUNITY • 2) PHYSICAL ENVIRONMENT FAcoRs AFFEctING NAtURAL VEGEtAIoN • RELIEF • LAND • SOIL • CLIMATE • TEMPERATURE • PRECIPITATION • SUNLIGHT • LATITUDE AND ALTITUDE NAtURAL VEGEtAtIoNs IN INDIA • Grow where temperature and rainfall are plentiful to support a tree cover. • Forests are classified into üTropical evergreen forests/ Rain forest üTropical deciduous forests/Monsoon forest üTropical Thorn forest and Scrubs üMountane forest üMangrove forest NATURAL VEGETATION IN INDIA Tropical evergreen forests • Occur in the regions near the equator. Also called tropical rain forests. • Hard wood trees like rosewood, ebony, mahogany, etc are common. • Forests remain evergreen. Tropical deciduous forests ØAlso called monsoon forests ØTrees shed their leaves altogether in dry season to conserve water ØTrees found are hardwood trees like sal, teak, neem and shisham ØAnimals are tigers, lions, elephants, langoors and monkeys Tropical thorn forest and scrubs ØIts found in the areas getting less than 70cm of rainfall ØFound in Rajastan. Gujarath, MP etc ØAcacia, date palm, cactus, different shrubs and grasses are found here Montane forest ØFound in hilly and mountain region ØVegetation varies according to the increase in altitude ØFound in Himalayan region Mangrove forest ØFound in coastal areas where mud and silt get accumulated It is found in the Delta region ØSundarban forest STEPS TAKEN TO PROTECT FLORA AND FAUNA ØIndian wild life act passed ØBiosphere reserves were established ØPeriodic census ØSpecial projects like project tiger ØHunting of wild animals is banned Wild life sanctuaries National parks BIOSPHERE RESERVES Formative assessment ØWhat is eco system? ØVegetation in most part of India is not natural. Give reason ØName the most wide spread vegetation in India ØName the 4 bio-reserves which have been included in the World network of Bio reserves ØName the state in which Simlipal bio reserve located ØName the different types of vegetation in India ØDistinguish between evergreen forest and deciduous forest ØGive a brief account of mountain vegetation ØWhat are the measures taken by the government to protest flora and fauna in India? ØHow does relief and rainfall influence the distribution of natural vegetation in India? Geographic Information Systems (GIS) and the Conservation and Use of Plant Genetic Resources Summary of http://www.diva- gis.org/docs/gis_pgr_conservation.pdf DIVA-GIS is a free mapping program, (GIS), that can be used for many different purposes. It is particularly useful for mapping and analyzing biodiversity data, such as the distribution of species, or other 'point-distributions'. Geographic Information Systems • Said in a simple way: ‘a tool for managing information of any kind according to where it is located’ • Main elements: • Data input, verification and editing • Importing digital datasets • Data storage, retrieval and management • Stored as data: vector and raster • Data manipulation and analysis • Bring diverse datasets together, make them compatible and combine and analyze them • Output • Selecting areas or layers for output on a screen Ecogeographic surveying Source of of information of such survey can be: • Herbarium specimens • Germplasm accessions passport data • Experts • Literature • Field notes • Maps Ecogeographic surveying – main objectives Identifications of geographic areas which are: • Likely to contain specific desired traits (adaptations), taxa or habitats of interest • Highly diverse (whether environmentally, taxonomically or genetically) • Complementary to each other • Currently missing or under-represented in conservation efforts • Threatened with genetic erosion Output: An example: Distribution of Oryza longistaminata In southern Africa. Images, aerial photographs, satellite imagery, and radar images combined with other sources of data High diversity areas • Usually begins with dividing the target area into a number of smaller zones e.g. climate zone • Different geometric, political, socio-economic spatial units have been used • More examples: presence/absence of species, measures of diversity based on morphological characters or molecular markers (to calculate the morphological diversity of Capsicum spp) Complementary areas • Analyses of diversity • E.g. compare two areas to see if they have the same diversity of taxa or morphotypes • Can allow the diversity measure to be weighted for the distinctness of taxonomic units (thus calculate diversity values, e.g. taxa closely related or not) Under-conserved areas • Identify individual species, species-rich areas and vegetation types that are not represented or underrepresented • To identify ecogeographical gaps in existing ex situ germplasm collection Threatened areas • To predict genetic erosion by documenting and modeling changes of forests, wetlands, different land use types and cropping • Indicators of desertification, soil erosion, increasing outmigration, and appearance of new fields of agriculture into increasingly marginal areas • Can use result to early warning of crop failure and famine in regions of the world Analyses • To map different areas from different datasets • A case study from four separate analyses, from which the results are combined to produce a single map of priority areas for conservation interventions (se next slide) High priority areas for conservation