Introduction
Allelopathy is when one plant causes a deleterious effect on another plant through the escape of allelopathic chemicals. Allelopathy can be used for protection from infections of fungal or bacterial organism, and/or can be a form of competition. Moreover, this form of competition could be used for succession or resource management. In this laboratory experiment, wheat (Triticum sp.) seeds were exposed to extracts from four plant species to determine whether or not these species processes inhibitors of growth. The extracts were from goldenrod (Solidago sp.), aspen (Populus tremuloides), black cherry (Prunus serotina), and aster (Aster novae-angliae). The quaking aspen is a deciduous tree native to North America. Aspens have shallow root systems, the ability to survive long term flooding, and formation of clones connected through root systems (USDA Forest Service “Species: Populus tremuloides”). Black cherry are widely distributed throughout the Eastern United States, can grow on wide variety of soils except for very wet and very dry soils, can grow on strongly acidic soils, can consist of multiple seedlings that germinate within the vicinity of the parent tree, are intolerant of shade, are considered intolerable of competition, and regeneration can have interference from certain herbaceous plants through allelopathic chemicals. For instance, Solidago rugosa release chemicals from leaves or roots that inhibit cherry succession. It has been suggested that black cherry may interfere with other tree species regeneration, such as red maple (Marquis “Black Cherry”). New England Asters grow in moist environment and have a wide distribution in North America (Nesom “New England Aster: Symphyotrichum navaeangliae”). Goldenrods ...
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...eld observation and laboratory experiment to determine whether or not allelopathy was the factor contributing toward succession in abandoned agriculture land. The researchers conducted laboratory bioassays and compared the results to the field. Looking at leaf extracts, long term successional data, germination rates in the lab, and field observations to conclude that goldenrod succession was not due to allelopathic effects. Furthermore, the inhibitor chemicals have more of an impact in control settings and not in the field, which was within their native range. Their theory was that soil organisms metabolized the allelochemicals in such a rapid manner that the concentrations decreased and effects minimized. On another note, allelopathy has been shown in other studies to have contributed toward invasiveness for Solidago Canadensis in Europe (Pisula & Meiners 2010).
Plant hormones are certain chemicals present in plants that control plant growth and development by affecting the division, differentiation, and elongation of cells. (Campbell, 2008) Each hormone has multiple effects depending on its site of action, its concentrations, and the developing stage of the plant. (Campbell, 2008) Auxin is a plant hormone that is synthesized within the apical meristems and young leaves of a growing plant. Auxin stimulates stem elongation when it is present is low concentrations. It promotes the formations of lateral and adventitious roots, regulates development of fruit, enhances apical dominance, functions in gravitropism and phototropism, promotes vascular differentiation, and retards leaf abscission. Gibberellic acid is one of several plant hormones that govern a plant’s growth. Gibberellins allow for stem elongation in plants. Plants without enough of this hormone tend to grow short or stunted. This chemical is high in the element potassium, which is one the main components of plant fertilizer and very important for plant growth on its own. The...
Timmons, J. B., Alldredge, B., Rogers, W. E., & Cathey, J. C. (2012). Feral hogs negatively affect native plant communities. Informally published manuscript, Texas AgriLife Extension Service, Texas A&M , College Station, TX, Retrieved from http://feralhogs.tamu.edu/files/2010/04/feral-hogs-native-plants.pdf
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
Batten disease or Neuronal Ceroid Lipofuscinoses (NCL) is nervous system disorder that is inherited. There is a few different age categories related to such disease but it usually manifests itself in childhood. Although Batten disease is the juvenile form of NCL, most doctors use the same term to describe all forms of NCL. Batten disease or NCL may be recognized by parents or doctors that notice a child begin to develop vision problems or seizures. In some cases the early signs are subtle, taking the form of personality and behavior changes, delayed speech, slow learning, clumsiness or stumbling.
Graves’ disease is considered an auto immune disorder. It is also a hyperthyroid disorder that leads to the over activity of the thyroid gland. Graves’ disease is a condition that occurs when the immune system mistakenly attacks healthy tissue. Many people suffer from symptoms. This paper will talk about the causes of the disease, research that has been conducted and how it can be treated.
During the nineteenth century a variety of alternative medical traditions became popular in the United States. There was a shift in how people began to view their physical, mental, and emotional health. A type of alternative medicine that quickly became popular in the United States and Europe was the tradition of hygeiotherapy. This form of treatment included hydropathy a type of water-cure treatment and combined that with exercise, dietary reform, sexual restraint, and any behaviors that were viewed as unhealthy.
The communities of various native plants have been significantly minimized as a result of ...
Rheumatoid Arthritis is when the joints are chronically inflamed, which happens because it is an autoimmune disease which means that the immune system attacks the body tissues. Although Rheumatoid Arthritis mainly affects the joints, it can also affect other organs.
Schumann, Gail L., and Cleora J. D'Arcy. Hungry Planet: Stories of Plant Diseases. St. Paul: American Phytopathological Society, 2012. Print.
“The word 'leukemia' is a very frightening word. In many instances, it's a killer and it's something that you have to deal with in a very serious and determined way if you're going to beat it” - Kareem Abdul-Jabbar. Many people, including tons of children, fight leukemia every day trying to beat this vicious cancer. Without knowing how leukemia is exactly caused, it puts a damper on how to avoid it.
Do you know what lymphoma is? More than one million people in the world have the cancer, and yet only half of the population knows what it is. A type of lymphoma called Non-Hodgkin lymphoma is one of the most common types of cancer in the United States, accounting for more than 4% of all cancer cases. Of all Americans, 2.1% will be diagnosed with this cancer in their lifetime, and yet as common as it is many still do not know of or understand lymphoma.
Janick. J. (2011). Center for New Crops & Plant Products - Department of Horticulture and
Plant defences are those mechanisms employed by plants in response to herbivory and parasitism. According to Hanley et al. (2007), “the tissues of virtually all terrestrial, freshwater, and marine plants have qualities that to some degree reduce herbivory, including low nitrogen concentration, low moisture content, toxins or digestibility-reducing compounds”. The type of chemical defence may be species specific (Scott 2008). The defences that plants possess may be in the form of chemical production or in the form of physical defences such as thorns or spikes and even through reinforced, rigid leaves. “The compounds that are produced in response to herbivory can either have a direct effect on the attacker itself (e.g. toxins or digestibility reducers), or serve as indirect defenses by attracting the natural enemies of the herbivores” (Bezemer & van Dam 2005). This essay will focus on chemical plant defences and in particular the effects of terpenes, phenolics, nitrogen-based defences as well as allelopathy in plants.
One of the most common mysteries in the world is the development of autoimmune diseases. An autoimmune disease is when the immune system, which usually keeps your body healthy thinks that your healthy cells are antigens and attacks them. This is irony right? It is against properties of evolution for an immune system to attack itself causing sickness and possibly death if untreated. There are about 80 different types of autoimmune diseases, which usually have periods of little to no symptoms and worsening symptoms. What particularly creates confusion in the world is the autoimmune disease, inflammatory bowel disease, which affects almost about five million people worldwide.
"Home | American Society of Agronomy." Home | American Society of Agronomy. N.p., n.d. Web. 25 Mar. 2014. .