The answer is d, due to the helms-burton act
Answer:
A) Even-aged stands are more vulnerable to bark beetles accurately describes a benefit or a drawback of managing an even-aged tree plantation .
Explanation:
Even - aged structure is called as the stand that has one distinct size and age . These types of plants are composed of fewer species than any other structures .and even less diverse .
Bark beetles are vulnerable to mature tress , older , even - aged stands that have regrown or been replanted after any disturbance events ,
For example , The wildfire is more younger and more diverse stands.
Water cutes out underground caves
Answer:
B. All of these are drivers
Explanation:
The populations of lot of amphibians, with rare exceptions, are constantly on the decline around the world. The main reason behind this is the human activity, as it has caused lot of changes, pollution, and dangers for the amphibian populations, which has led lot of amphibians to be on the verge of extinction.
The pollution, especially of the waters, has been a major factor for the decline of the amphibian population. Lot of very toxic chemicals have made the water unsuitable for living and poisonous, which systematically killed off the amphibian populations.
The habitat loss, as with any other group of animals, has left the amphibians without places to live. They have been left without their shelters, food sources, mating grounds, and they have started to die out.
The invasive species, especially the predatory ones, have also had big negative impact. The amphibians didn't had any defense mechanism against the introduced predators, so they were easy prey and their numbers rapidly went down.
Explanation:
4.The Great Unconformity of Powell in the Grand Canyon is a regional unconformity that separates the Tonto Group from the underlying, faulted and tilted sedimentary rocks of the Grand Canyon Supergroup and vertically foliated metamorphic and igneous rocks of the Vishnu Basement Rocks.
5. They may form at all types of plate boundaries, but the thickest sedimentary rock accumulations occur at convergent plate boundaries. Metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. 6. One of the best-preserved records of these events is in the bottom of the Grand Canyon—in a package of sedimentary strata known as the Tonto Group.
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