I.

    Community HabitatDefinition:1.    A community can be defined as several interacting populationsthat inhabit a common environment and are interdependent with each other. Eachpopulation has characteristics like natality, mor­tality, age structure, growthdynamics, and so on, but when several populations share a common habitat andits resources, they interact among themselves and develop into a bioticcommunity or simply, a community.2.

    A habitat is the place where plants and animalsnormally live. It is, simply, the place where you can find communities. Differencesof community and habitat:              Thekind of community you find is mostly defined by the type of habitat it islocated at, and communities are often named after their habitats. A habitathowever, can hold different types of communities. Example is the rainforest.The rainforest is the habitat where the rain forest community, a population ofdifferent plants and animals, live. But a rainforest can also contain an insectcommunity composed of different interacting insect populations, or a streamcommunity, located in a stream in a rainforest where different insects andamphibian population interact with each other within the stream and forming acommunity. II.

   Biodiversity              Biodiversity is the variety of livingorganisms, their number, and their variability or the simply diversity of lifeon earth. This includes all the species, the diversity between species and withinspecies, and the diversity of different environments present in the biosphere. Theconcept also covers how this changes from one location to another and over time.Importanceof Biodiversity:              Biodiversity is very important inthe maintenance and improvement of the ecosystem.

Each specie, no matter howbig or small has a role to play in the ecosystem, and the interactions thattakes place within and between ecosystems make up the life on Earth. Althoughthe ecosystem is governed by cycles like the water cycle or the nutrient cycle,there is a constant change happening, especially in organisms. As eachorganisms reproduce, they make offspring that although identical to theparents, are still unique in their own way. The environment changes too, andthe organisms have to adapt to survive. These organisms depend on each other tosurvive, and the more diverse a place is the more services an organism can giveto support others as well as more sources to support itself.

              One example of the importance of biodiversityis when a species is diverse, it also means it contains a wide range or avariety of genetic material. It is known that in-breeding usually results ingenetic defects in animals, including humans. When a specie is few in number,there is a lack of variety of genetic material as well, leading to offspringthat are born without the means to survive and this could eventually lead toextinction. An extinction of a specie could lead to imbalance in an ecosystemthat would take years to recover from.               The same principle can be appliedto crops.

Crops that are asexually propagated or are cloned from a single motherplant usually have shorter life-spans and are more susceptible to disease. Thelack of diversity removes an organism’s ability to adjust to change and adaptto its environment.               If taken in the context of humanbenefits alone, biodiversity means a wide range of resources to use. A diverseplant populations, for example, could potentially contain medicinal value thathumans could use. If rice, for example, is a diverse plant species. If rice onlycomes in one variety, then it could only be grown in a particular strict set ofconditions and would only contain a single set of properties.

It would havebeen very difficult to grow and it wouldn’t have been the staple food for mostof Asia.  LivingPlanet Index              The living planet index is theindicator of the state of the world’s biodiversity, measuring the trends inpopulation of vertebrates in marine, freshwater, and terrestrial species. Thetrend shows that since 1970-200, there is a decline in the biodiversity. Thisis largely caused by human intervention in the ecosystem.

We disturb it in away that doesn’t give it time to recover. The decline is because of pollution,climate change, the destruction of habitats, excessive tree logging, etc.III.  Trophic Function           Trophic Function, or Functional Response,represents the consumption of prey assuming a given number of predators. Functionalresponses describe the relationship between an individual’s rate of consumptionand food density. They have generally been divided into three types: Type I,Type II, and Type III           Simply put, Functional Response is howa prey or predator behave when one or the other is abundant or scarce. Type I                    Type I is the increased consumption offood by an organism. It is the constant intake of food modelled aspredator-prey relationship where the consumption of food does not interferewith searching for food.

This means the prey and the predator increases linearly.The predator does not need to find food because it is always present, and theprey is abundant enough that there is no threat to its decline by predatorconsumption. The amount of prey is proportional to the amount of predator, andthere is no hunting involved.          The type I functional response can bedescribed by a linear equation of the form y = ax + b, where a is the slope of theline and b is the intercept, as seen in Figure 3.  TypeII           In the type II functional response,the rate of prey consumption by a predator rises as prey density increases, buteventually levels off at a plateau (or asymptote) at which the rate ofconsumption remains constant regardless of increases in prey density.          It is the decrease of feeding activityof a predator because there is a constant supply of prey and the predator doesnot have to spend time hunting for prey.

This could mean that the number ofprey is higher than the number of predator, making it easier for the predatorto hunt for it’s prey and is thus satiated. Figure 4 illustrates Type IIfuntional response when plotted into a graph. TypeIII           Type III functional response issimilar to type II in that at high levels of prey density, saturation occurs.          In type III, there is a prey switchingof predators. The population of a certain prey is low and to survive they wouldhide, making them harder to find. The predator will then have look foralternative prey. This could mean that the number of predator is more than theprey population, and they find it harder to find prey because of cometition.

Intype III the predator takes a considerable amount of time hunting, either fortheir main prey or for other prey. When plotted in a graph, type III wouldappear like the example in Figure 5. IV. Competitive Interactions within Communities              Competition is occurs when alimited resource is needed by two or more species. When two or more niches overlap,chances are a certain resource becomes difficult to obtain. That’s whencompetition happens.

The more niches that overlap, the more chances that acompetition happens.              Competitions are necessary becausein a way, it is the nature’s way to balance itself out. It is also a good wayto weed out the weaker or the inferior specie, making way to stronger and moreadaptable species.Typesof Competition:1.

    Interspecific Competition – a form of competition inwhich individuals of different species compete for the same resources in anecosystemExamples: 2 predators with the same prey; weeds and cropscompeting for soil, water and sunlight;2.    Intraspecific Competition – a form of competition betweenorganisms of the same speciesExamples: A pack of wolves eating the same carcass; wildrange chickens compete for food3.    Exploitative Competition – a form of competition when allindividuals have the equal access to the resource, but differ in how fast orhow efficiently they can exploit itExample: Birds on the forest competing on fruit availablein trees;4.    Interference Competition – a form of competition whencertain individuals are able to restrict or prevent access of others to theresources and so control the use of it.Example:animals marking their territory and attacking anyone who enters it; two maleanimals fight for a mate V.  Interaction Among Biotic Communities           Organisms interact with each other inorder to benefit and survive. Different interactions are as follows:1.    Predator-Prey – Interaction can benefit both species.

Preyobtains food and the reduced numbers in prey means more resources for those individuals(prey) that are left2.    Consumer-Producer – the consumer benefits3.    Commensalism – an interaction of two species where in onespecies benefits while the other is not affected4.    Mutualism – aninteraction of two species wherein both benefits from each other5.    Parasitism – aninteraction between two species wherein one species benefits and the other isharmed VI.

 Conclusion           In a community and/or ecosystem,different interactions takes place and different factors affect theseinteractions that ultimately affect the balance in an ecosystem. A habitatholds and is composed of communities that interact with one another. The differentinteractions in the community depend on one another and is centered in thesurvival of the organisms. The more diverse a community is, more interactionstakes place and the more resources can be found, both for the organisms and thehumans. Lastly, humans create a huge difference in the interactions of thesecommunities as a human can manipulate its surroundings and would cause a lot ofdamage if left unchecked. By understanding how the interactions in a communitywork, we could use it for our benefit with, hopefully, minimal damage to thecommunity.