Casey Schmidt Mid-Term Dr. Brinkerhoff Advanced Ecology Whether or not a species is rare or common depends on the stage of the community in which it lives, how the species functions within that community, and how effectively it gathers and allocates its energy resources. The niche which the species occupies can determine the carrying capacity of the species. For example, some species are limited by intraspecies competition, or by Gausian competitive exclusion (Hutchinson 1957). This means that though a species’ fundamental niche, or all the space that theoretically meet the conditions that the species needs to survive, may allow them to have a broad range, competition with another species may limit that species to a smaller realized …show more content…
Some species are good at early colonization, taking advantage of the sparse competition to establish themselves in an uninhabited place (Gleason 1926). Dispersal refers to the mechanism through which a species is able to travel and how far. High dispersal will result in a species being able to travel large distances and may result in higher colonization. Population levels for the mites were increased when aids to their dispersal were provided because they were able to reach more resources. R-selected species tend to be more common than K-selected species worldwide. R-selected species are generally smaller and live shorter lifespans, but also produce more offspring more quickly. K-selected species, on the other hand, are larger, but produce less offspring to spend more time rearing them. This is why the rabbit is more common than the elephant, for example, even though they are on the same trophic level. In our ever changing world, some species have become more common because they are able to adapt to climate change, become invasive species, or are able to compete with invasive species. As temperatures rise, generalists and species with effective dispersal will be better able to adapt. Species limited to a small range, a range at high elevations, or limited by ineffective dispersal, will be at risk of becoming more rare or extinct (Saltre et al. …show more content…
Heterogeneity can create specific habitats for different types of species and places where niches do not overlap. Therefore, if a species were to land on the island, they would be more likely to find suitable habitat. Over long spans of time, species can evolve to fit the landscapes better, filling unfilled niches and adapting to better compete for resources. These species can evolve into entirely new species, adding even more to the number. In contrast, small islands (or areas in general) are more likely to either be homogenous or be heterogeneous with habitats too small to support many
In other words, a fundamental niche is where an organism can use all the resources (food, shelter, light, etc.) it needs to survive and reproduce without the interference from other species. This takes ideas from Elton because it states that food is an important part of a niche. However, Hutchinson also introduced the realized niche, the actual niche that an animal is restricted to because of outside forces such as predators and competition (Hutchinson, 1957). This is similar to Grinnell’s idea because the California Thrasher could live outside the chaparral zone because it has a diverse diet, but its realized niche is the chaparral zone because it is restricted there because of predators. Because of this, niches aren’t easy to define in nature because scientists can figure out what the ideal niche would be for an organism but multiple outside forces can make it difficult to determine its realized niche. In recent years, niche theory has not been restricted to ecology and in fact can be applied to cancer research. Studies have found that stem cells differentiate into cancer stem cells causing Cancer in
4) My small island results compared with my large island results came out as like the species number on my small island went down while the changes in species number for my large island went up. I feel that this result could have been predicted by the species-area formula. The reason is because since my big island is a lot bigger than the small island, it can hold up to 2x the animals than the small island could. Another reason is that when the island increases, the extinction rates slow down and try to balance towards a greater biodiversity unlike with the small island where extension rates are going
Nonnative species can also be called alien, exotic, or nonindigenous. Their presence is due to humans dispersing them to other locations beside their native habitat, or by humans creating environmental conditions that allow their growth. When nonnative species begin to take over a new habitat and displace native species, they are then termed an invasive species. Nonnative invasive species are one of the biggest threats to ecosystems in North America (Cox, 1999) because they are able to have an impact on many levels, including ecosystems, communities, and populations (Cushman, Tierney, & Hinds, 2004).
Biodiversity is the variation and amount of species across the globe, or within in a specific geographical habitat. There are three different areas of study within biodiversity; ecological diversity, species diversity and, genetic diversity. Science Book Species diversity is the variety of different organisms and relationships within a specific species, this essay will discuss the declining of species diversity among sea turtles and the implications it has on the worldwide seas. I have chosen to research about the topic because, sea turtles are believed to have been alive during the Jurassic period. However, now all seven sea turtle species are critically endangered or vulnerable, due to human activities such as; commercial fishing, bycatch and, climate change. (WWF, OCEANA, ACTIONBIOSCI)
2. Montane museum hypothesis- Montane regions have higher species richness at intermediate level simply because these elevation was occupied for the longest time which means high time for speciation and accumulation of species (Kozak and Wiens, 2010).
In this chapter, Darwin addresses the relationship between geographic isolation as well as migration in the formation of species. He notes that resemblance between organisms in different parts of the world with similar conditions has nothing to do with the climatic conditions where the organisms live. He explains that species separated by huge land or water area are very different because there is no possibility of migration and as such natural selection acts on each species based on the environment they’re in. Species that are not separated by huge barriers develop some sort of affinity and the possibility of migration and species introduction reshapes the process of natural selection. Darwin also mentions that the process of species development
A different scenario takes place when an alien species is transported to a new area. Although direct competition with similar species is still a problem, the new kid in the block may have no natural pests and diseases. Thus, large stands of monocultures can occur. It is generally accepted that one plant species will support 10 species of animals. If one species takes over 99% of a given habitat dozens if not hundreds of species are lost from that area and some populations are stressed enough that extinction is possible.
A niche is a position or role taken by a kind of organism within its community. Such a position may be occupied by different organisms in different localities. Over time, animals have evolved through natural selection to their physical structures, physiology, and behavior to survive. These changes have helped determine the niche in which an animal is placed. It is impossible for two different species to have the same niche. The determinacy of a niche consists of three components: dispersal of ability—how well individuals or their offspring can move from place to place—tolerance to different environmental conditions, and interactions with other niches. An organism with high dispersal ability may not be affected as much by spatial structure.
If this means a species needs more space for living or a particular topography than the probability is greater on larger islands. As for disturbance frequency, on smaller islands, it is more likely that disturbances such as human-environmental interactions will occur with more intensity and more frequently subsequently harming the populations of both groups. For example, if humans start cutting down trees on island 5 vs. island 7, there is a greater chance that tree was home to a warbler on island 5. Immigration will inevitably affect both groups of species where we see more immigration linked to superior genetic makeup and improved survival of organisms. For this case there is no correlation with distance from the mainland and richness, so that is not the sole source of
On the first level, when foreign, but previously non-invasive species is first introduced to a new area, the new species may play a role in a community that was previously unfulfilled; it may fill a vacant niche in the ecosystem. Originally this new species may be seen as a useful contributor to its new surroundings because it has only (temporarily) increased biodiversity in the area (Meinesz, 2003).
Darwin’s observations from the islands made him want to come up with some explanation to why this occurred. He began to do research of each the species that had lived on these islands and observe all of the characteristics that had. He noticed that the islands h...
There are many reasons for differing diversity and abundances of species between two countries, and I believe I have touched on the most important aspects of them all. It looks as though Spain’s proximity to the equator is the driving force behind its high species numbers, but as all organisms are different and prefer various habitats and environments, that there are also a lot of problems with comparing and analysing data. In this time of climate change, all that we know about species diversity could change and so studies such as this are very important in understanding how global temperature change and melting ice caps affect the organisms that live on this planet.
A pair of equal sized birds of prey might overhunt an area and compete for food. However the Ecological theory shows validity in the idea that a territory is not overhunted because a small male will eat small prey while the large female hunts larger prey. However, it does not adequately explain why it is the female who would eat the larger prey or the bigger portion and be the bigger mate. It also does not explain why some species have smaller RSD than others such as the Screech Owl for
Other animals include marine life, mammals, insects, birds, and many more. Combined, ecosystems were established throughout the world for the survival of many animals. Survival for animals on earth has been challenging over the billions of years. Areas where animals associate themselves, ecosystems and survival patterns begin to establish throughout various species. In time, some species become endangered which can lead to extinction. Being identified as an endangered species involves the likelihood of becoming extinct. The probability of a plant or animal becoming extinct determines whether the plant or animal should remain endangered. Endangered species generate around the world in various regions and climates. Unfortunately, endangered species often involve low numbers of population for a specific species. The numbers help present the growth rate of different species in specific areas. Keeping track of the numerous amounts of plants and animals in the world continues to challenge scientists, but the challenge helps establish a species population. While the endangered species around the world continues to increase, the importance of preventing species from becoming endangered requires a great amount of research. Knowing the different ways to positively prevent endangering species and the
Earth is a beautiful planet formed by human beings, plants and animals. While human beings are thriving in the world today, animals and plants are not doing so well. People today have knowledge of the many different species, but some of the species are now endangered in certain countries where there is no protection for animals. Endangered species are groups of organisms which are at risk of becoming extinct for one or more reasons. There are many reasons why a particular specie may become endangered. Although these factors can be analyzed and grouped, there are certain causes that appear repeatedly. The main causes of species decline are overexploitation of animals, loss of natural habitat, and global warming. Today there are approximately 1300 endangered or threatened species in the United States.