1/13/2024 0 Comments Blue planet biomes grasslandsThe largest national forest in the US, the Tongass, preserves important old growth forest of this type and is considered the crown jewel of the national forest system. Perhumid Temperate Rainforest receives significant precipitation every month of the year, with an annual total of more than 100 inches. The Chugash National Forest, just east of Anchorage, conserves part of the boreal rainforest and is an important stopover place for migrating shorebirds. The low species-richness is believed due to the young age of this forest, only colonized by trees since the relatively recent retreat of Pleistocene glaciers. Western hemlock and Sitka spruce are dominant and may grow up to 100 ft tall. Wetlands, including muskeg and meadows, increase habitat diversity. It grows amidst alpine glaciers on the shores of Prince William Sound. Boreal rainforest is the northernmost expression of the biome in northwest North America. Major changes in species composition occurs along the 23° latitudinal extent of the rainforest, and ecologists recognize four major forest types:Ĭourtesy Diego Delso I. contorta), Yellow cypress ( Chamaecyparis nootkatensis), and in the south, coast redwood (Sequoia sempervirens). Common species are western hemlock ( Tsuga heterophylla), western red cedar ( Thuja plicata), Douglas fir ( Pseudotsuga menziesii), silver fir ( Abies amabilis), shore pine ( Pinus contorta subsp. Tall, spire-shaped trees, often draped with epiphytic lichens, grow in dense stands. This coniferous forest is the largest extent of temperate rainforest on the planet. They sustain marine mammals as well as birds, bears, and even wolves. Interestingly, Pacific salmon are the keystone species in these coastal forests. High atmospheric moisture also slows rates of decomposition and leads to thick organic layers on the forest floor and peat bogs in northern parts of the biome. Frequent fog and near-constant cloudiness keep humidity high and forest fires a relatively rare occurrence. Precipitation occurs throughout the year, becoming more seasonal farther south where a mediterranean regime (i.e.,winter precipitation) influences rainfall patterns. Steppe grasslands lack trees except along the banks of rivers and streams.The regional climate is maritime with no extended periods of great warmth or cold. The grasses found in the steppe are much shorter than those of temperate and tropical grasslands. Steppe grasslands: Steppe grasslands border on semi-arid deserts.Tropical grasslands are found in Africa, India, Australia, Nepal, and South America. Their soil is very porous and drains rapidly. Savannahs are dominated by grasses but also have some scattered trees. They have warmer, wetter climates than temperate grasslands and experience more pronounced seasonal droughts. Tropical grasslands: Tropical grasslands are located near the equator.The soil of temperate grasslands has a nutrient-rich upper layer, but fires that prevent trees and shrubs from growing often accompany seasonal droughts. Temperate grasslands include tall-grass prairies which are wet and humid, and dry, short-grass prairies that experience hot summers and cold winters. Temperate grasslands: Temperate grasslands are dominated by grasses, lacking trees and large shrubs.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |