Introduction Interactions in between plant species are of great importance and often result in fierce competition within the community. Over the past decades, increasing in human activity and movement allowed certain species to migrate beyond their origins and vastly expand in population, plants being one of the most complicated organisms on earth were highly involved in such activity. This enabled invasions by alien plants which poses serious threats and may inflict negative impacts to native species of plants in an certain ecosystem. Due to this nature, it may be concluded that there are certain traits and characteristics in these plants that allowed for the dominance to occur. It is crucial to be able to identify these traits to prevent …show more content…
alien plants migrating and impacting other local ecosystems. Many naturalized invasive plants were intentionally introduced due to their usefulness, although some may have been unintentional. Nevertheless, these species share a several highly distinctive traits that are well-defined, to endow success in competition when brought to exotic environments. These traits often include photosynthetic rate, high specific leaf area (SLA), high relative growth rate, long fruiting period and high efficiency in manipulating available resources. A study conducted by (xxxxx) which drew comparison between Robinia pseudoacacia (exotic) and Quercus acutissima (native) demonstrated these typical characteristics. R. pseudoacacia has a fast initial growth spurt that leads it to acquire resources faster than Q. acutissima and eventually overtopping the latter for light competition. It also allocates more resources for photosynthetic machineries inside leaves instead of thickening the structure to provide extra defense which enabled R. pseudoacacia to reach maximum possible photosynthetic rates and biomass production. (xxxxx) gave evidence to demonstrate a general perspective of this case, exotic plants had a much more significant relative growth rate as well as specific leaf areas than their coexist natives. These two traits are said to be of great importance for exotic plants to thrive in new ecosystems and may help to identify invasiveness of plants prior to importation. Exotic species often allocate most of the resources to modify their own structure to confer to successive competition. Much like invasive plants sacrificing defensive capabilities to maximize energy exchange, according to (xxxxx), invasive Ailanthus altissimaI in Switzerland has a relatively low radial growth rate compared to its coexisting natives, however, it was able to distribute a large quantity of its biomass on the stem above ground to reach the overstory and compete for radiant energy. The biomass allocation strategy was rather evident in (xxxxx) where R. pseudoacacia was able to form a extensive root system that contains both deep roots and a widely spread horizontal network of roots. Coupled with its exceptionally high biomass production, it may acquire the maximum rooting space as well as infiltrating into the natives' rooting system to derive additional resources that would consequently suppress the latter's growth rate and further development. In addition, invasive plants are said to have the potential to alter ecosystem cycling processes through their litter products.
(Steven D)'s study on Hawaiian rainforest ecosystem reflected invasive plants' ability to stimulate the nutrient cycling within soils to establish a positive feedback from its surroundings and thereby gaining the advantage over native species. As said before, invasive plants have typical characteristics of high growth rate and photosynthesis. The Hawaiian invader plants were found to have a very high SLA and generally utilizes limited resources to construct their leaves resulting in a much thinner foliage made easily accessible for decomposers. The high rate of growth subsequently corresponds to elevated level of nitrogen and phosphorus consumption in invader leaves to support energy exchange. This has significantly altered soil systems in the nutrient-poor Hawaiian ecosystems. The result of this study which contained the most widespread plant invaders in Hawaii identified their capabilities to produce a much heightened amount of nutrient-rich litter that decomposes many times faster than the native species. Most Hawaiian invasive plants are angiosperms which utilizes this method to create rapid nutrient turnovers and dominate the understory that displaces the native …show more content…
ferns. This isn't the only example where the invaders alters its migrated environment to gain some advantage. Study by (xxxx) identified the highly aggressive Alliaria petiolata capable of producing secondary compounds in which the introduced ecosystem are not familiar with. These particular compounds assist the invader to inhibit growth of native competitors by reducing the abundance of the mycorrhizal fungi and subsequently interfering with mycorrhizal mutalisms in the understory of local forests. Some invasive plants have distinct traits that allowed not only for the dominance but also a highly dispersed impact range.
According to (xxxxxx)'s study, bear-grass was introduced into Fushun, Liaoning Province due Northeast China during the 1980-1990 period, the plant itself produces large amount of caryopsis with burs and spikes on the surface which enables them to cling onto a variety of mediums ranging from skin of animals to tires of vehicles. With this particular trait, bear-grass has now spreaded into Hebei Province, Beijing and made drastic impact on Inner Mongolia grasslands. The study also had a major focus on risk assessment of invasive plant species in different types of ecosystems which has identified the successive establishment of multiple exotic plant species in farmlands and wastelands. It predicted that the dominance was due to extensive farming significantly changed the soil and vegetation which made suitable for introduced exotic plants, although the study also mentioned the continuous plowing pressure hindered the further development of alien perennial plants and only invasive annual plant species were able to thrive. Although no clear evidence was given in this study to explain this phenomenon in wastelands, low competitive capability of native species, lack of invader-specific pathogens and herbivores were likely to be the factors made wastelands vulnerable to mass
invasion. On the contrast, grasslands had a significantly lower invader species highlighted in the study which were due to grasslands having a highly diverse native perennial plant species and above-average population density and richness that are likely to hamper invasion progression by introduced species.
Next, the kukui tree’s physical features have all contributed, in some way, to its adaptation here in Hawaii. The kukui tree is such a resilient and adaptive species because it can be commonly found in various parts of Hawaii. It is able to grow in a variety of conditions such as different types of soils, a pH of 5-8, being able...
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.
Each plant species has a unique pattern of resource allocation that is genetically determined but not fixed. Plants can adjust there allocation pattern when they experience different environments and the presence of other species. Phenotypic plasticity goes hand in hand with resource allocation as well. When a plant has to adjust itʻs resource allocation, sometimes it uses itʻs resources to help the plant grow different characteristic so that the plant can have a greater chance of living in the environment. For example, if a plant from an environment that does not experience wind on the regular basis enters a new environment that has a lot of wind the plant may change itʻs resource allocation and spend more of itʻs resources growing deeper
Should exotic snakes or other large reptiles be allowed as pets in Florida? Right now these escaped/released feral reptiles create an estimated $120 billion in environmental damage each year according to David Steen on Slates Animal Blog.
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
Invasive species are organisms that harm a new environment that they are not native to. Many invasive species like Eurasian milfoil are easily able to reproduce and can do so fast. Due to this, the limited space in a body of water or area of land is quickly taken over by the invasive species so other native plants face the risk of death or even extinction. Overall, these invasive species can do great harm to an ecosystem or an economy, causing problems that are destructive to numerous organisms.
A serious problem that affects Hawaii today is the decline of natural forests due to the importing of invasive species and widespread deforestation. Majority of Hawaii’s natural forest have depleted and what is left is either being used for housing and farming, or preserved by the state. Little has been done to combat this besides the 1% of State funding that’s being used to run preservation systems.
For a species to survive and flourish within a given environment, it not only needs to replace itself but also all the other species around it exclusively. Hence, if one species completely replaces another species, the result is a single dominant species, a monoculture (source 2). According to Gause’s law, every species in a given environment occupies different niches for survival. Therefore, two separate species competing for similar resources cannot fundamentally coexist (source Gause). This is known as the competitive exclusion principle. When comparing animal niche’s to that of different autotrophic plants, one can rather easily differentiate adequate ecological niches for the animal species merely based on food-requirements (P.J. Grubb). On the contrary, many autotrophic plants contradict the competitive exclusion principle by sharing similar ecological niches such as sunlight, carbon dioxide, water, and alike mineral nutrients (p.j. grubb).
Through millions of years of evolution, well-balanced habitats have co-evolved to provide for the wide variety of species and their needs. Trees have adapted to weeds, weeds have adapted to the predation from herbivores, and so on up the food chain. Similar scenarios are seen throughout the world. Through the process of natural selection, specific species or broad species families will go extinct. However, these occurrences have largely been due to the natural flow and evolution of time. It wasn’t until recently that dominant species, such as humans, have taken the course of nature into their own hands.
Niskern, Diana. Invasive species. Washington, D.C. (101 Independence Ave., S.E.): Science Reference Section, Science, Technology, and Business Division, Library of Congress, 2004.
The Yasuni National Park possesses very diverse rainforest which significantly impact how the ecosystem functions; yet the the processes of disturbance and succession greatly affect them ("Yasuni National Park, Ecuador", "Ecuador Yasuni ITT Trust Fund" ). Just one hectare of the park contains more species of trees and bushes than all of North America ("Foreseeable Impacts of Oil Industry Activity in Yasuní")! There are a staggering 1762 species of trees and shrubs that have been identified in Yasuni, and approximately 400 of them are inherent to the region (“Foreseeable”). Hundreds of the plants in the previously untouchable zones have not even been classified or studied in depth (“Foreseeable”). The park is also paradise to a multitude of animal...
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.
The “disturbed preserves” are areas in which there has been human alteration of the landscape, whether it be infrastructural installations or beaten trails, that has then been left alone. These areas are recovering forests that normally transition from primary growth to secondary, but are made vulnerable through these artificial developments that alter the dynamics of the landscape in which the native species would emerge. Consequently, these sites, which are protected via the Lullwater Management Plan regardless, have grown into monoculture communities that consist usually of only one or two invasive species. The most aggressive invasive within Lullwater is Ligustrum sinense (Chinese Privet), which is a semi-evergreen shrub of great phenotypic plasticity, allowing it to invade and thrive in a wide range of habitats. Figure 2 is a dam and culvert constructed in 2003, which
Invasive species, (also known as invasive alien species or simply alien species) are defined as any organism (plant, animal, pathogen, or other living thing) that is alien (non-native) to an ecosystem, which can cause adverse economical, ecological, or health effects to native species and/or humans. The roots of these problems all stem from the massive negative ecological impact these organisms are having on the environment (CBD, 2009). For all animal extinctions where the cause is known since the 1600’s, invasive alien species have been a contributing factor 40% of the time (CBD, 2006); the second most contributing factor to extinctions after loss of habitat (GC, 2013). By eliminating native species through competition for resources, predation, and transmittal of disease, invasive species continue to reduce biodiversity in almost all ecosystems around the world (CBD, 2009). In the future, this problem may worsen, and if no action is taken, could lead to a cascading ecological problem so large that whole communities or even ecosystems could collapse.
Invasive species are species non-native to the ecosystem and its introduction causes or is likely to cause economic harm, environmental harm, or harm to human health. Most invasive species can be animals, plants, or other organisms. Invasive species are more likely to be introduced to a new ecosystem by humans. There are three specific invasive species that are causing huge harm in the United States: Asian carp, quagga and zebra mussels, and earthworms. Invasive species can be native in one place and can be pests in other places.