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
Invasive species as a whole have become a nuisance to many habitats and ecosystems around the world. What defines an invasive species is the following. It must be a species that is foreign to the habitat it resides in, have no natural predators which allow it to reproduce in such a rapid manner, and out compete native animals of food and shelter (Rosenthal 2011). These characteristics are what create such high populations of these invasive species in various habitats around the globe.
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).
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
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
In many parts of the world, ecosystems’ temperatures begin to rise and fall to extreme levels making it very difficult for animals and plants to adapt in time to survive. Climate has never been stable here on Earth. Climate is an important environmental influence on ecosystems. Climate changes the impacts of climate change, and affects ecosystems in a variety of ways. For instance, warming could force species to migrate to higher latitudes or higher elevations where temperatures are more conducive to their survival. Similarly, as sea level rises, saltwater intrusion into a freshwater sys...
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...
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).
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.
The warblers and larger mammal species on these islands are being affected by similar abiotic factors, but in differing ways for the biotic factors. Specifically, species richness is being affected by island biogeography and its associated costs (abiotic) as well as biotic aspects such as competition, predation pressure, and resources. First, looking at figure 1 we see a strong correlation between species richness, represented by number of different species/island, and land area on each associated island for both larger mammals (R2=0.94) and warblers (R2=0.84). This shows us that the island geography, particularly how big it is, has strong correlation to the number of different species on each island. Land area is related to a number of abiotic features such as environmental heterogeneity, disturbance frequency, distribution, and immigration (Brown et al., 2007).
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
Climate Change is any substantial change in climate that lasts for an extended period of time. One contributor to current climate change is global warming, which is an increase in Earth’s average temperature. Plants and animal species throughout the world are being affected by rising temperatures. Many plants are flowering earlier now than they once did; animals, such as the yellowbellied marmot, are emerging from hibernation earlier; and many bird and butterfly species are migrating north and breeding earlier in the spring than they did a few decades ago, all because of slight changes in temperature cues. (Shuster)
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.
The earth has experienced many unexpected outcomes over the years. The changes on earth have affected many animals, plants, and ecosystems. Different kinds of species stay involved with the dramatic changes the earth has went through. The past includes climate changes, distinctions, meteorites, and evolution processes. The changes on earth will always impact different species no matter where the species occupies. The changes on earth have led to many species becoming endangered. Endangered species continue to increase and without help, earth’s species will become distinct. Many factors contribute to why animals become endangered such as environmental changes, lack of resources, new species, and the evolution most species encounter throughout