Hares were introduced into a grassland ecosystem. They don’t have any natural predators there, and they can eat native plants for food. What are the outcomes of this situation?
Match the inheritance patterns with the scenarios that exemplify them.
codominance
multiple alleles
incomplete dominance
A pink roses are formed when red roses are mated with white roses.
arrowRight
Genes with the alleles IA, IB, and i are responsible
for expression of A, B, and O blood types.
arrowRight
A red flower and a white flower produce
an offspring with equal proportions of red
and white coloration.
Answers
Answer:
Explanation:
There is a variety of definitions for grasslands:
"...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation."[1]
"...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000)[1]
"A region with sufficient average annual precipitation (25-75 cm) to support grass..." (Stiling, 1999)[1]
Semi-natural grasslands are a very common subcategory of the grasslands biome.[4] These can be defined as:
Grassland existing as a result of human activity (mowing or livestock grazing), where environmental conditions and the species pool are maintained by natural processes.[5]
They can also be described as the following:
"Semi-natural grasslands are one of the world's most biodiverse habitats on a small spatial scales."[6]
"Semi-natural grasslands belong to the most species rich ecosystems in the world."[7]
"...have been formed over the course of centuries through extensive grazing and mowing."[6]
"...without the use of pesticides or fertilisers in modern time."[8]
There are many different types of semi-natural grasslands, e.g. hay meadows.[8]
Evolutionary history
The graminoids are among the most versatile life forms. They became widespread toward the end of the Cretaceous period, and coprolites of fossilized dinosaur feces have been found containing phytoliths of a variety of grasses that include grasses that are related to modern rice and bamboo.
The appearance of mountains in the western United States during the Miocene and Pliocene epochs, a period of some 25 million years, created a continental climate favourable to the evolution of grasslands.[9]
Around 5 million years ago during the Late Miocene in the New World and the Pliocene in the Old World, the first true grasslands occurred. Existing forest biomes declined, and grasslands became much more widespread. It is known that grasslands have existed in Europe throughout the Pleistocene (the last 1.8 million years).[8] Following the Pleistocene ice ages (with their glacials and interglacials), grasslands expanded in the hotter, drier climates, and began to become the dominant land feature worldwide.[9] Since the grasslands have existed for over 1.8 million years, there is high variability. For example steppe-tundra dominated in Northern and Central Europe whereas a higher amount of xerothermic grasslands occurred in the Mediterranean area.[8] Within temperate Europe, the range of types is quite wide and also became unique due to the exchange of species and genetic material between different biomes.
The semi-natural grasslands probably first appeared with the human starting farming. So for the use of agriculture, forests got cleared in Europe. Ancient meadows and pastures were the parts that were suitable for cultivation. The semi-natural grasslands were formed from these areas.[8] The removal of the plants by the grazing animals and later the mowing farmers led to co-existence of other plant species around. In the following, the biodiversity of the plants evolve. Also, the species that already lived there adapted to the new conditions.[8]
Most of the grassland areas have been turned to arable fields and disappeared again.
Nowadays, semi-natural grasslands are rather located in areas that are unsuitable for agricultural farming.[8]
Ecology
Biodiversity
Grasslands dominated by unsown wild-plant communities ("unimproved grasslands") can be called either natural or "semi-natural" habitat. Although their plant communities are natural, their maintenance depends upon anthropogenic activities such as grazing and cutting regimes. The semi-natural grasslands contain many species of wild plants, including grasses, sedges, rushes, and herbs; 25 plant-species per 100 square centimeters can be found.[8] A European record that was found on a meadow in Estonia described 76 species of plants in one square meter.[8] Chalk downlands in England can support over 40 species per square meter.
In many parts of the world, few examples have escaped agricultural improvement (fertilizing, weed killing, plowing, or re-seeding). For example, original North American prairie grasslands or lowland wildflower meadows in the UK are now rare and their associated wild flora equally threatened. Associated with the wild-plant diversity of the "unimproved" grasslands is usually a rich invertebrate fauna; there are also many species of birds that are grassland "specialists", such as the snipe and the little bustard.[10] Owing to semi-natural grasslands being referred to as one of the most-species rich ecosystems in the world and essential habitat for many specialists, also including pollinators,[7] there are many approaches to conservation activities lately.