Winter squash is an excellent source of vitamin A, vitamin C, alpha-carotene and beta-carotene. It is also a very good source of thiamin, vitamin B6, potassium, magnesium, and manganese, and a good source of iron.
Spiders are, for the most part, such generalist feeders that they kill many useful insects as well as many pest species, however because pest species are by their nature more numerous than beneficial species they are still effective. They are of great value to the environment.
Lichens play a very significant role in our biological world. For one, they act as air pollution indicators. Although a lichen is able to withstand harsh conditions, such as freezing, thawing, high light and heat intensities, when an area is polluted, lichens will become scarce and eventually stop growing. Lichens also help regulate the composition of gases in the earth's atmosphere. Each creature acts as a sponge to catch and store excess gases, one of which is carbon dioxide. In essence, lichens help filter the air we breathe. Some lichen also have the ability to return valuable nitrogen to the soil. These are three significant roles lichens have been found to play; however, as research continues, more are sure to be uncovered.