A. increased demand for natural resources; need to create environmental laws to protect natural resources for human consumption; need to develop air quality control systems for big business; need to ensure proper disposal of human waste
The Pteridopyhta, phylum of seedless vascular plants has about 1000 known living species, including those in the genera Lycopodium and Selaginella; the gametophyte of some of these species cannot photosynthesize, and instead uses mycorrhizae to obtain nutrients.
Explanation:
The pteridophytes, most advanced group of plant among the cryptogams i.e. seedless plants.
They are first land plants that have developed a well defined vascular system.
Ferns, horsetails etc are common members of this phylum.
Answer: Soil moisture and fertility
Cheat grass is likely to decrease the soil moisture of the region, thus rendering the soil infertile and unfit for other plants growth.
Explanation:
Cheatgrass is an exotic weed native to Europe, West Asia and Northern Africa. Cheatgrasses outcompeted native vegetation as a result of large number of livestocks like cattle and sheep into sagebrush region. The livestocks overgrazed on native vegetation, which resulted to a void filled rapidly by Cheatgrass.
Cheatgrass grows on pastures, hills, and ranges. Wildfires promote more Cheatgrass but destroy native plants vegetation. Cheatgrass can survive drought due to deep root system they possess. The deep root system make the plant to grow and flourish with even small amount of water. Its deep root system reduce soil moisture and deplete soil fertility, preventing the growth of other plants. Also, Cheatgrass is self germinating and require les soil to grow. All these attributes that favor Cheatgrass have threatened native plants such as sagebrush plants and woodlands.
Organisms compete for the resources they need to survive- air, water, food, and space. In areas where these are sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem boasts high species richness (diversity).
