Ecology

Various land biomes encountered by a traveler (from the equator to arctic polar ice cap continued... 

-Coniferous forests (aka boreal forests) found North of the deciduous forests. This is the taiga biome. 
-triangular shaped; trees of boreal forest are evergreens (cone bearing/needle leaved trees consisting of spruce, fir and tamarack). 
-Winters of taiga are extremely cold and during the summer the subsoil thaws and vegetation flourishes. 
-Tundra is the most continuous biome and is found in a circle around the north pole. 
-Tundra is characterized by a mixture of lichens, mosses, grasses, sedges, and perennial herbs (able to withstand often freezes) 
-Permanent layer of frozen soil lies a few inches to feet below the surface 
-Mammals of the tundra: birds, reindeer, lemmings, caribou, arctic wolves, foxes, hares, polar bears (in short, number of different species is limited) 
-The biomes of the desert regions and the sclerophylous bushlands are irregularly scattered around the world but have distinct form 
-The bushlands are characterized by gnarled/twisted and thorny/rough plants. 
-Leaves tend to be dark, hairy, leathery, or thickly cutinized. 
-Climate is mostly a hot dry summer and relatively cool moist winter 
-Deserts have the most extreme temperature fluctuations. Day= intense sunlight/high temperature Night = heat rapidly lost and becomes bitterly cold 
-Most desert animals active at night (also have physiological/behavioral adaptations for life in such an environment) 

Why isn't a biome map of the earth a true representation of the vegetation formations found on land? 
-Easy to find boundries between land formations (desert/mountain/sea etcc) but there really are no distinct boundries on the ground. 
-Real vegetation types usually grade one into another so that it is impossible to tell where one formation ends and another begins 
-Map makers draw boundries using what seems to be the middle of the transitions and then is parceled out by clocks of formations of plants 

Why do ecologists not attempt to divide the ocean into biome types like those on land? How do they instead distinguish between different parts of the ocean? 
-Ocean is too vast (ocean/seas cover 71% of the earth), uniform, and holds a comparatively rapid mixing of the organisms in it. 
-Ocean characterized by a range of habitats which are interconnected 
-Less complex in structure/productivity 
-Continental shelf- depth of 200 m or so dramatically drops to about 3000 m + (ocean floor) 
-Neritic zone: waters over continental shelf 
-Water beyond edge of continental shelf= ocean basiin 
-Floor of ocean basin is the abyssmal plain is marked by sea mounts, ridges, and trenches 
-Oceanic zone into 4 zones: upper=euphotic (sunlight for photosynthesis), next is bathyal, below that is the abyssmal zone (waters over ocean floor) last trenches/valleys of the ocean floor form the tidal zone 
-Total darkness=aphotic zone 
-Neritic zone has greatest variation in temp, salinity, light intensity, and turbulence plus most diverse amount of plant/animal life 
-Edge of the ocean= intertidal/littoral zone. 
-Next is subtidal zone