8.2 Lichens and Mycorrhizae | Endomycorrhizae and Ectomycorrhizae Fsc biology class 11 скачать в хорошем качестве

8.2 Lichens and Mycorrhizae | Endomycorrhizae and Ectomycorrhizae Fsc biology class 11

#Lichens #lichen #mycorrhizae #endomycorrhizae #Ectomycorrhizae #fscbiology #irtisamsbiology Have you ever seen a lichen and knew that it was a lichen? Not many people know what lichens are, and who would? They seem as though they are from another planet! Lichens are bizarre organisms and no two are alike. Lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an alga. The dominant partner is the fungus, which gives the lichen the majority of its characteristics, from its thallus shape to its fruiting bodies. The alga can be either a green alga or a blue-green alga, otherwise known as cyanobacteria. Many lichens will have both types of algae. Lichens are important for several reasons. One of the most obvious is that they are beautiful to look at. How enchanting would the Pacific Northwest be without the long drapes of Alectoria sarmentosa (witch’s hair) hanging from the branches of the old Douglas firs and Sitka spruce? How colorful would the rocks and cliffs be in the Rocky Mountains without the reds, yellows, and greens of the crust lichens? Without these living creatures hanging off of trees or clinging to rocks, our natural areas would look pretty boring and a little more lifeless. Mycorrhizae are a symbiotic association between plant roots and fungi. Their major role is to enhance nutrient and water uptake by the host plant by exploiting a larger volume of soil than roots alone can do. Mycorrhizae come in a number of forms, dependent upon both host plant and fungal taxonomy. The distribution of these forms in ecosystems is related to host plants distribution and the climatic and soil conditions. The ability of mycorrhizae to improve host plant nutrient and water acquisition and to help in defense of root pathogens and root grazing can alter the host plant performance. By differentially altering the performance of individual species within the community, mycorrhizae can influence plant community composition, enhance competition, and create synergism through the sharing of resources between species. Mycorrhizal fungi and their fruiting structures are important sources of food for both invertebrate and vertebrate animals. Mycorrhizae are being used in agriculture, forestry, and restoration to improve yield and to overcome some of the pollutants associated with plantings on disturbed sites. The ability of mycorrhizal fungi to accumulate heavy metals and radionuclides make them possible candidates for restoration and remediation of polluted environments. Change in our environment from pollutants, climate change, and loss of habitat have altered the relative abundance of mycorrhizal fungi to saprotrophs resulting in the need for enhanced efforts in fungal conservation.