Forestry represents a sizable portion of man’s environment. It covers approximately 1/3 of the entire surface of the Earth and about the same of the continental United States of America. Unless man seriously disturbs or alters this cover, or there are serious catastrophic events, Forest continues to live on in an indefinite basis in a given area of land. The contribution of forests towards the economic stability of nature benefits many forms of life, and that includes man. Ecology is also known as the science of the interrelationships between organisms in and to their complete environment. Forestry ecology is concerned mainly with the forest as a biological community. It deals with the interrelationships between the various trees and other living organisms comprising the community and with the interrelationships between these existing organisms and the physical environment in which they continue to exist. In other words, the study of the forest ecosystem is forest ecology.
The type of forest that we are talking about is going to be based on what are the predominant trees which are growing in a given site and that is used to classify a plant community. The ecological system or the ecosystem, it is the habitat than a forest survives in and the forest community. Technically speaking, an ecosystem is a biological term applied to a part of nature, such as the forest, which includes both nonliving material and living organisms as part of the ecosystem. An ecosystem could well be likened to an aquarium in which the water, containing a number of dissolved minerals, constitutes the physical environment. Sunlight enters the tank allowing the green plants to grow. The plans give out oxygen. The fish in turn feed on plants. Fish excrement helps feed the green plants. This environment survives entirely on its own for a time. A forest is similar but on a much larger scale.
Lobsters are invertebrates, which belong to the Crustacean class of the Phylum Arthropoda. There are two different families of lobsters existing in the United States. They are the American lobster and the spiny lobster. American lobsters are clawed lobsters which are classified under the taxonomic family Nephropidae, or large marine crustaceans. Spiny lobsters are without claws, but with a pair of horns that can be seen above the eyes. You can find five pairs of jointed legs in a lobster. They come in a variety of colors, sizes, and forms. Their sizes range from 1-12 inches. The basic parts of a lobster include abdomen, antennules, antennae, crusher claw, pincher claw, carapace, cephalothorax, pereiopods, eye, maxillipeds, telson, uropods, and mandible.
Abdomen is the tail section of the lobster which is composed of seven segments. Antennae are sensory organs, which functions as a chemoreceptor. Antennules help to perceive distant odors. The external shell of the cephalothorax is called carapace. Cephalothorax, one of the main parts of a lobster, is covered by the carapace. It is made up of the head and the thorax. The larger claws are called as the crusher claws. These are very useful for crushing prey. Ripper or pincher claws are the smaller claws. A lobster has a pair of compound eyes providing sense of sight. The functions of the mandibles and maxillipeds are to grip and shred its food. Pereiopods are two sets of walking legs suitable for burrowing. Central tail fin is called telson and outer pairs of tail fins are known as uropods.
Lobsters live in burrows in the muddy areas at the bottom of the ocean. Smaller ones are called as lobsterettes. Similar to all arthropods, lobsters must molt in order to grow, leaving them vulnerable during this time. Most lobsters are carnivores and feed on clams, carrion, mussels, snails, worms, sea urchin, and other lobsters. Like the grasshopper, the nervous system of a lobster is very primitive. Approximately 100,000 neurons are present in a lobster. Usually, the color of its blood is grayish. The large blood vessels circulate its blood from the heart which is located behind the stomach. Lobsters take in oxygen from the water through the gills, found in the lobsters’ thorax section.