The Effect of Increasing Flooding Magnitude, Research Paper Example
Words: 6410Research Paper
The Effect of Increasing Flooding Magnitude on Trees of Floodplain Forest With Special Consideration to Mississippi River
This paper is based on identifying the impact of the rising magnitude of flood on the floodplain forest tress in regards to the Mississippi River. There is a very crucial role played by the floodplains in the preservation of the Ecosystem. It is because of the floods that the ecosystem has evolved itself to combat against the natural disasters. Most of the plant species have grown resilient with the increase in the floods and due to its impact (Cosgriff et al, 2007). There are different hydrological and anthropogenic factors which are analyzed in this paper that pinpoints the culture changing in the flooding in the floodplains of Mississippi River. The research by Pinter et al. (2006) showed the increasing flooding magnitude on the Floodplain Forests and trees. He has contrasted the results in trends of flood stages. In relation to the Rhine River and Mississippi river system he concludes that the changing patterns of flood in the floodplain of the Mississippi river is the main reason because of the aggressive channel engineering history of the Mississippi River.
The paper will further study the impacts of the increasing flood plains on the trees in relation to Mississippi river. The conclusion in this research shows that flooding is a natural part of the eco system. The change in flooding’s timing, duration, and magnitude will affect the floodplain forests in two ways. First of all, the forest structure will change due to the negative effects of flooding on seed dispersal, seedlings and tree growth. For example, small tree will decrease from forest while the older trees’ size will increase. Another reason is the decline in the diversity of the forest due to human activities and dams constructions. This has resulted in the lack of trees being adapted to cope up with the incline in the floods severity. According to that these floodplains would have much better diversity if the ecological disturbances would be intermediate as oppose to frequent or rare. In order to understand better the impacts of the floodplain forest and magnitude, there is an increased research required on the diversity, average size and the density of the plant. This paper will address the degree of change in the regimes of flood to identify the management approached. The mush better perspective tool used will be done in consideration with the floodplains of Mississippi River.
Flooding plays a very important role in floodplains ecosystem. Due to floods the ecosystem has evolved to defend against this natural disaster. Most species of plant have grown resilient to the effects of floods (Cosgriff et al, 2007). However, plants require access to free water and transfer of O2 and other gases between soil and atmosphere and due to floods this becomes difficult (Drew, 1997). Flooded plants suffer on multiple levels including seed germination, vegetative and reproductive growth and increase in plant mortality (Kozlowski, 1997). Compared to them, trees respond very differently than plants when it comes to flooding. It could be said that difference in tolerance levels within one ecosystem makes the concept of flood tolerance a difficult idea to define (Kabrick et al, 2012). When it comes to trees both biotic and abiotic factors play their part in defining a particular tree’s resilience towards floods. Even age and size are also an important factor which could be used to determine tolerance of a tree. Because of this trees within same specie would react differently when faced with flood.
Other factors to consider are the frequency and duration of the flood (Kozlowski and Pallardy 1997). Frequency and duration of the floods, if they are increased, would cause the trees to deal with floods for longer periods of time and it also hampers their ability to recover. This results in higher mortality rate and slower growth rate (Cosgriff et al, 2007). There can be many reasons for an increase in flooding frequency and duration. Hydrology of most rivers is now different because of the sedimentation that happened in last century and this is the cause of different nutrient cycles and effects on biodiversity (De Jager et al, 2012).
The floodplains of most rivers now have different flooding duration and frequency and, consequently, a different ecosystem. The plant and tree life in these regions face longer flooding pattern and higher frequency of floods which changes their growth pattern and mortality rate. Spanned over the century, this shift in flooding has transformed some of these regions’ ecosystems (De Jager et al, 2012). Considering the Mississippi River, the agricultural growth, urban development, natural riverine flood pulses, the rising water table, and island loss are some of the most important anthropogenic and hydrological factors to consider when presented with the radically transformed ecosystem of Mississippi River’s floodplains (Cosgriff et al, 2007). In the previous century the climate shift continued with increased rate and some extreme weather events resulted in increased frequency of flooding and heavy rainfall (Lau et al, 2010). Sparks et al (1998) suggests that the increase in flood magnitude started in 1880s. Since then the trees in these regions are now dealing with a changed climate and different flooding pattern which stresses them and their defense mechanisms.
The purpose of this paper is to understand the transformed ecology of the Mississippi River’s floodplain forests through using flood as stress on ecology and flooding tolerance in trees’ defense mechanism. The paper would also attempt to pinpoint the major factors which are contributing in the flood magnitude of Mississippi River. For this purpose the effects of floods on trees with different sizes and ages within the same specie would be shown and it would also be analyzed how the trees’ flooding tolerance is playing its role in Mississippi River’s floodplain forests.
Mississippi river flood change
There are many different anthropogenic and hydrological factors which must be analyzed to pinpoint the changing culture of flooding in the Mississippi River’s floodplains. Pinter et al. (2006) studies these factors in “Trends in flood stages: Contrasting results from the Mississippi and Rhine River systems” and concludes that the changing flood patterns in the Mississippi River’s floodplain is mainly due to the aggressive channel engineering history of the Mississippi River. Although this does not mean that there are no other factors at play here but considering that channel engineering is one of the main ways in which human being engage and manipulate the rivers and it impacts the whole hydrology of the river so it could definitely be a contender for prime suspect in this case.
In the Mississippi River the channels were constricted to increase navigation depth (Pinter et al. 2006). The study conducted by Pinter et al. (2006) compared the hydrology and anthropogenic factors of Mississippi River with Rhine River and the results showed that the navigational infrastructure on Rhine was in much better condition than Mississippi River. The main effect of channel engineering on Mississippi River undermines its ability to pass a flood through it. This lack of efficiency results in number of problems regarding the flooding of the Mississippi River’s floodplains. First of all this increases the duration of flood because Mississippi River cannot efficiently convey the flood flow through itself. Secondly, the frequency of floods also increases due to climate changes which happen because of the increased duration of the floods. Lastly, both of these factors combined with the floodplains give us a new ecological space. Plants and trees braving longer and frequent floods change their adaptability or simply die out. The paper would now elaborate upon each factor in Mississippi River and analyze their inter-connection through local data and data from other rivers in general.
Flooding is considered a major disturbance to trees on many different physiological levels (Figure 1, Glenz et al., 2006). Stomatal closure and decrease in transpiration show that there are different degrees of plant’s physiological responses and that the ability to deal with osmotic stress varies from plant to plant (Achenbach and Brix, 2013). On top of this, the impact of flooding could also be seen in decreased photosynthesis rate in plants (Junior et al, 2012). Flooding causes the roots to die and this death limits the plant’s ability to absorb nutrients. This also changes the root’s metabolism which is increased because of root death. The roots start to breathe faster and soil microbe respiration decreases the rate of oxygen present in the soil. When the rate of oxygen is decreased in the soil then the roots changes their respiration mechanism from aerobic to fermentation as a response. However, the reduction of Adenosine triphosphate acidifies the cytoplasm which leads to slower proton translocation. This decreases the rate at which roots absorb water (Herrera et al, 2008).
The factor which affects plants the most is the reduction of oxygen in the soil. This makes it difficult to exchange gases between roots and soil. Oxygen shortage cause low soil redox potential, and low soil nutrition such as NO? 2, Mn2+, Fe2+, and H2S, and interference between microbial carbon metabolism (DREW, 1997). The limited soil-atmosphere gas exchange lead to lower rate of oxygen, accumulation of toxins like superoxide radical O2- and increase of carbon dioxide within the soil (Glenz et al, 2006).
Another effect of lower oxygen rate is on plants’ physiological and metabolic pathways which lead to lower growth rate and plant mortality (Glenz et al, 2006). The lack of oxygen also damages the root causing low nutrient uptake and leaf growth, increased leaf chlorosis which leads to leaf senescence and abscission (Kozlowski 1997; Glenz et al. 2006). Decrease in oxygen rate could also result in lactic acid accumulation and lactic acid fermentation that decreases cytoplasmic pH (Herrera et al, 2008) and lower pH levels can damage the cells (Roberts et al, 1984. Gibbs and Greenway, 2003). Another factor to note here is that different flooding types can affect the oxygen rate differently. For example standing water floods have lesser amount of oxygen compared to flowing water floods (Kozlowski and Pallardy 1997).
Specie of the tree, the size of the tree and the duration of the flood are considered when gauging the flood tolerance of a tree (Romano, 2010). This tolerance could be lower in some cases and can be limited to few hours while in other cases this tolerance could stretch up to several months (Vartapetian et al, 1997). Floodplain species have morphological and physiological adaptations to live on anaerobic situations such as aerenchyma tissue, adventitious water roots, hypertrophied lenticels (Martin et al., 1993. Romano, 2010). These mechanism allow for higher oxygen absorption rate from tissues in stem and leafs which is then carried on to the roots. However, trees’ response mechanism works in different ways when face with major climatic shifts and this subject is not well understood but some studies suggest that the decrease in oxygen rates in the soil forced the trees to develop other sources for the supply of oxygen (Herrera et al, 2008).
One of the first responses generated from the flooded plant’s defense mechanism is the closing of stomatal. The time it takes for the plant to achieve stomatal closure and the how much stomatal closure happened are the main determinants of the flood tolerance degree present in a species (Pezeshki 1993).Yet, Kozlowski (1984) reports that in the situation of adventitious roots growth some tolerant species, could re-open stomata under flooding.
Flooding has both negative and positive effects on seed and seed dispersal. Flooded area contains water dispersal species. Flooded areas contain species which uses water dispersal of seeds and 40 different species were found using dispersal via water in cypress swamps (Middleton, 1995). The seed dispersal time window of some species was associated with the normal flooding season which is during the month of April, May and June (Romano, 2010). McQuilkin (1977) reports that Quercuspalustris(pin oak) acorns dispersion usually happens in spring flooding. However, some species have longer dispersal periods of 7 and 8 months such as A. negundo (ash-leaved Maple) and F. pennsylvanica (green ash or red ash) (Schopmeyer, 1974). For this reason, timing is a major factor that determines the success of a seed in germination (Middleton, 1995). Seed dispersal and germination timing for tree species at the upper Mississippi floodplain forest can be seen in Table 1 (Romano, 2010). The succession of floodplain forest is affected by timing of seed dispersal and seedling requirements (Romano, 2010).
Succession is an ecological process in which the biotic community structure is transformed over long periods of time into a stable and diverse community. This happens after a biotic community is disturbed through natural or human activities. Here in floodplains the increased frequency of floods and the longer periods of floods affect the succession in the forests (Sahney, Benton and Falcon-Lang, 2010).
In contrast to this, flooding may affect seed germination because of the requirements of the seed life history characters. Most of seeds of the trees need the absence of flood to germinate. The decrease of oxygen rate due to flooding would, consequently, affect the seed germination. Oxygen is required for many physiological processes involved in seed germination (Kozlowski and Pallardy, 1997). Another thing to consider here is that flooding also contributes in lower survival rates of seeds. This happens because the seeds have a precise time-of-emergence but the flood can temper this time-of-emergence thus lowering seeds’ survival rate (Middleton, 1995). Thus changes in flooding patterns could lead to changes in seed distribution and flood dispersal mechanisms. Another thing that happens due to this transformed ecological response to new flooding pattern is the decrease in seed production rate in flooding periods (Middleton, 1995).
There exists a balance between generation of life and the termination of life in earth’s ecosystem to create more and more diverse living communities. The seed represents the generation of life while the flood is responsible for the mortality rates in plants and trees. While the seed dispersal did not increase nor the seed became more resilient to flooding, the floods increased in their duration and frequency. This broke the previous balance that existed within the floodplain forests and the floods. It can be seen here that seeds are affected on every level of their physiology. From time-of-emergence to dispersal and to germination many physical and chemical influences on the seeds are changed because of the different pattern of flooding. This show how on the most fundamental levels of seeds, an ecosystem and the biotic community in it is affected by the floods.
Seedlings and young trees are more affected by floods compared to adult trees. Cosgriff et al. (2007) suggested that there is a contrast relationship between mortality rate and diameter of the trees which is why seedlings and young trees are more prone to death due to floods and seedlings are also covered in water completely in a flood which severely limits their survival options. Kabrick et al (2012) worked in an outdoor laboratory to study three different treatments that mustered the effects of timing and the movement of flood on six hardwood species seedlings that occur in the floodplain forest. These species included Populusdeltoides (eastern cottonwood), Quercuspalustris (pin oak), Quercus bicolor(swamp white oak), Quercusmacrocarpa (bur oak), Juglansnigra (black walnut) and Caryaillinoinensis (pecan).
The result suggested flood treatments strongly reduced survival (P\0.01), stem growth (P = 0.05), and basal diameter growth (P = 0.02). Compared to this the standing water treatment have much higher dieback or mortality rate due to lower Oxygen levels in the soil, lower pH and a lower dissolved oxygen concentration. In the species level response study black walnut were found to have the highest mortality rate and reductions in their diameter growth when faced with floods. White oak and pin oak seedlings, on the other hand, have the highest survival rate while white oak also possessed a higher growth rate.
Some seedlings in particular species could show higher survival rate compared to the older plants within the same species. Craine et al, (2006) reported that mortality rate in three month-old pitch pine seedlings is lower than 15-month-old seedlings or 5-year old saplings in root-flooded situation. This shows that the tolerance to flooding could decrease with age in some species.
The same study by Craine et al, (2006) shows that the seedling which survived a flood before have higher resistance to next flooding. Pre-flooding seedlings reached the 50% mortality rate after 16th week of flooding, while seedlings which were never flooded before died within 10 weeks. Pre-flooding seedlings only showed higher survival in very shallow water. The three month-old pitch pines survival rate of two weeks flooding was 90% and survival rate of four week old seedlings was 5% (Craine et al, 2006).
Here it can be seen that flooding interacts with seedlings on many different levels and there is balance that co-exist between them but due to changes in flooding patterns of Mississippi River’s floodplains, the balance is lost. The magnitude of the flood and its growing intensity and frequency is something which the seedlings are not adaptive enough to persevere. The effects on seedlings are drastic and with every flooding more and more are dying which again effects not only the total population of the forest but also the biodiversity that exists within it. Every tree and plant in the floodplains is there because of their developed mechanism to handle floods. But the flood frequency and duration is increasing constantly now and most these plants have inadequate defense mechanisms. They don’t have proper systems in place to increase their chance of survivability in the event of flooding. This results in new types of chemical processes and, in some conditions, the disappearance of some chemical processes from the ecosystem of the floodplains. The life in the floodplains is deeply affected by the increase in flood magnitude.
Even though flooding is natural part of floodplains ecosystem but still changes in flooding pattern could increase the mortality rates in trees while limiting their growth rates. Additionally, the occurrence of flood in growing season could also contribute in the same results (Cosgriff et al, 2007). For example, Pérez-Ramos et al. (2009) reported that oak growth increased after eliminating surface flooding, which suggests flooding is stressful even to flood tolerant species (Herrera et al., 2008).Large-scale flooding increased the mortality rate, even in well flood adaptive forests. In 1993 flood at floodplain forest, all forest communities suffered from high mortality rate. 60% of mixed forests, 41% of maple-ash and 42% of oak suffered from high mortality rate in that event (Cosgriff et al, 2007).
Most woody plants suffer from reduction of shoot growth, root formation, root branching, root decay and root growth under soil flood (Kozlowski, 1997).The mechanism of shoot growth activates by overcoming leaf development and leaves growth affecting early leaf senescence and abscission (Kozlowski, 1997). According to Polomski et al (1998) observations, the main root dieback by flooding increased the development of younger roots. The decrease of shoot and root growth is caused by the physiological and metabolic pathways inhibition or confusion. Oxygen plays an important part here because the lack of it results in lower absorption of oxygen and water and macronutrient uptake (e.g. nitrogen, phosphorus, potassium) by the root system. It has also been shown that flooding conditions cause a drop in nitrogen fixation (Kozlowski, 1997). Therefore, the increasing of atmospheric evapotranspiration demand (AED) cause trees with root hypoxia suffer from losing in water transpiration (Lukac et al, 2010), and restricted hydraulic conductivity of roots (Sellin 2001).
Here it can be seen that floods can have a varied and drastic effects on tree growth. A tree’s response to flooding is dependent on several factors including species, genotype, age, quality of floodwater, flooding time and duration (Kozlowski, 1997). Flooding in growing season could drastically effect growth stages of flood intolerant trees and compared to this flooding in dormant seasons has little to no effect on the trees (Kozlowski, 1997). The main reason for this damage is oxygen limitation which is an essential part of flooding and this oxygen limitation leaves little or no oxygen for the active roots (Kabrick et al, 2012). Floods that span over the land for longer periods could easily kill most of the trees in a floodplain forest while the floods which are only present for shorter period of time, introduces stress on the ecosystem. This stress would cause some trees to die while limiting growth of other trees (Junior et al, 2012).
Photosynthesis decreases in flooded plants due to the stomatal shutdown, which leads to a reduction in productivity and leaf growth. Translocation of photosynthetic goods from leaves to roots will decrease in flood conditions (Gravatt and Kirby, 1998). Other plant responds to flood by increasing the growth of their stem’s diameter (Kozlowski, 1997). McKevlin et al. (1995) reports increase in height, diameter and biomass growth rates in flooded Nyssa Aquaticseedlings which increase the efficiency of plant nutrient absorption.
Here it is visible how new floods patterns have engaged with the ecosystem. In some cases this harshly affected the ecosystem and resulted in irreparable damage to tree life in the floodplains of Mississippi River. In other cases the plants and trees responded to this new condition of increased floods and their durations. They increased their growth rates and growth patterns to increase their biomass, height and diameter. Here this engagement between new flood pattern and ecosystem could be seen clearly. New patterns of flooding means transformation on a regional scale and one side of the transformation means increased mortality rate and reduce growth rate while other side of the transformation is evolved defense mechanism in some trees and plant species.
Variation in flood duration and magnitude:
Upper Mississippi River forest is suffering from increasing durations of floods. The number of flooding days is recorded and it was found that in the past 30 years the flood duration has increased significantly enough to affect the ecosystem of this forest (De Jager et al, 2012).Because of higher water surface it was recorded that flood intolerant tree species were lost in the Mississippi forest such as Quercusspp and the understory trees generation was also reduced (De Jager et al, 2012) (Romano, 2010).
Magnitude of the flooding is one of the main factors contributing in species arrangement and spices survival (Ishida et al. 2007). The increase in intensity, duration and frequency of flooding increase the understory cover because of the increase of light due to gaps and the decrease of water and nutrients competition (Cosgriff et al, 2007). Moore et al (2011) suggested the intensity of flood will lower the landscape level and the local diversity. This happens because of the lack of adaptability in species which were present in the region in more frequent flooding times. Landscape level and local diversity decreases with less frequent yet more intense flooding events. Therefore, it can be said that species diversity is at its peak in intermediate zones between the frequency of flooding and the intensity. This supports the Intermediate Disturbance Hypothesis (Wilkinson, 1999).
The Intermediate Disturbance Hypothesis (IDH) is a concept which connects species diversity with ecological disturbances (Wilkinson, 1999). According to Intermediate Disturbance Hypothesis, the species diversity is on the peak when the ecological disturbances are balanced. It means that if the ecological disturbances would occur frequently or occur rarely then species diversity would not be maximized but if the ecological disturbances are intermediate then the species diversity would be at its peak in the given region.
De Jager et al, (2012) suggested that the diversity of tree species increases if the flooding occurs for less than 40% of the growing season.At the same time the increase in flood time from 0% to ~25% affects the understory diversity and from 0% to ~40% the over story diversity. Increase in the mortality rate of small trees lead to change in tree densities and average tree size (Niklas et al. 2003). The broader disturbances affects forest community in the same way like a biochemical processes would affect it (De Jager et al, 2012).
Knox (2006) explores the pattern of flooding in Mississippi River from a different perspective. He explores the human side of this natural disaster and what anthropogenic activities contributed in the rise of flood’s magnitude. For past 200 years people developed more and more room for agriculture and removed the forests. This destroyed many elements which, previously, kept the magnitude of floods in check. Even though people have stopped doing that but the disturbance introduced in the flood pattern have become self-sufficient and it seems that it would continue to reshape the biodiversity of the region until it would run its natural course.
The effect of high magnitude and low magnitude flooding can also be seen in Australia documented by Pettit et al. (2001). The study showed how high magnitude floods reshaped the ecosystem and affected the biodiversity. In this case the biodiversity was increased and the tree communities formed clusters. Whereas, the low magnitude flooded forest showed stable growth pattern and stable biodiversity without much variation. This gives a very good comparison space where two almost same forests are exposed to two different flooding magnitudes. The results suggest that a forest with high magnitude flooding could have serious adaptability problems. The study also states that the flood patterns in this region were also changed because of the development of grazing grounds for livestock and agriculture. This provides framework to understand a change in natural environment through human activity. Any human activity however small and continued for few centuries would make serious connection with local and global climatic shifts. The floodplains of Mississippi River and other floodplains of different rivers are dealing with the industrial and metropolitan shift in human society and the result is that the ecosystem of many areas is at risk now. Not only a better river management system is needed but also a deep understanding of human/ecology connection is required to fully understand and deal with the increasing problem of high magnitude flooding.
If all of this is understood in the context of IDH (Wilkinson, 1999) then all the pieces of the puzzle falls in place. As discussed in the beginning of the paper, the extensive channel engineering and channel constriction on the Mississippi River becomes a strong and seemingly permanent cause of increase in flooding frequency, intensity and duration due to the compromised navigation infrastructure in Mississippi River. This introduces a change in the ecological system of floodplains because they now have to deal with floods which are longer and invade the floodplains more frequently. The Trees cannot adapt to this change for two reasons. First of all, there is no breathing room for trees to develop adaptability therefore more and more trees are dying. Secondly, the chemical and biological processes that are happening in this ecological system of Mississippi River’s floodplains are starkly different than the same processes happening 30 years ago (De Jager et al, 2012). Intermediate Disturbance Hypothesis assumes that regions with frequent or rare ecological disturbances have compromised diversity and the paper’s investigation into the matter revealed that IDH makes the most sense to explain the ecological shift in the floodplains of Mississippi River and what caused it.
According to Rappaport (1989) and Cairns (1977), there are 3 ecosystem health requirements and they are as follows;
- The habitats supports the ecosystem and are viable from the plant populations and native animal synonymous to those before any disturbance present.
- The pre-existing condition in relation to the eco-system after the disturbance whether it is human induced or natural.
- The system of Ecology is itself able to sustain.
In linkages with the health of environment of the floodplain of Mississippi River, the studies shows that the activities of human like logging of the forests of the floodplain gives the steamboats fuel and eliminates snags for enhanced navigation which impacts negatively the natural processes viability which are happening on the plains of flood (Cairns, 1977; Rappaport, 1989). The ecosystem as such doesn’t support the viable plant and native animal’s populations or the habitat synonymous to the disturbance present before. So, it is not able to transform back to its condition pre-existed once the ecosystem is being disturbed. This is the reason why the ecosystem is not able to sustain itself properly (Cairns, 1977; Rappaport, 1989).
In the research conducted by Lubinski Kenneth (1998), he figured out that the large floods that are significant helps maintain the ecological health of the river. Moreover, he also noted that the absence of these infrequent and large floods tends to debilitate the health of the ecosystem river. The ecology of Mississippi river has suffered because of the development of controls of human and their activities like levees and dams which are intended for the channelizing of the river of Mississippi to the agricultural and urban areas used by humans.
The human interventions impact like manipulation channel is also supported by the Wildlife Study and U.S fish department (2006) that has confirmed the Illinois Rivers and Mississippi river flows. This has been changed by the installation and building of thousands of wing dams, 37 dams and 8,000 levees miles (2006). This research help other parts noted in the paper that shows the multilayer floods per day frequency. The magnitude is exaggerated for this flooding which has impacted negatively the viability of the life of plant in this region (USFWS, 2006). To further help this study, it has been shown that the Mississippi River flooding is higher than 9 feet and this was the reason of the pre-disturbance. Due to this reason the natural environment has been degraded.
In another research conducted by Klass, Hoover & Knutson (1996), there has been a focus on the considerable loss of habitat of floodplain which is viable as indicated in the thinning number specifies of the bird songs. The change prevalence has been caused because of the anthropogenic disturbances which has disturbed the lower and the upper forest societies which are crucial for the ecosystem health. The narrow corridors creation through the creation of channel has resulted in the scattered forest prevalence fragments which has cause the forest diversity degradation. This is noted by the song bird’s significant declining in the population (Knutson,et al., 1996).
The flooding regime determination is needed to help the floodplain trees in the Mississippi river. This is because these floodplain forests are crucial for the effective conservation under the alteration of the human ubiquitous activities in the flows of rivers. In comparison to the impact of flood plains on the trees in Mississippi river the wood abundance is necessary for the decline in the invasive species with flooding. Such kings of prone to flood surfaces are determined jointly by the hydrograph characteristics and the topography of the region. This results in the incline of the floodplain habitat availability with the watershed area increasing and declining at the gradient of stream. The main stem downstream provided reached with the most habitat of the floodplain which is associated largely with the features of low energy like the point bars and back swap. These are dominated by the maple silver. In order to figure out the suitable site in the large tributaries and the basin’s upper part, these often are linked with the islands and bars in channel and the domination of the frequency which is the cause of the flood disturbance impacting the dependent species and the trees in Mississippi river. The results of the research implied that the flows of restoration by the dam operations’ modification can benefit the floodplain trees on the Mississippi river which needs to conflict with the regional setting with the protection of flood. These outputs underscore how flow, specifies traits and geomorphology interact with the characteristics patterns of the vegetation of floodplain. These interactions forms the basis of the river restoration and conservation effective system.
This study concludes that even though flooding is a natural part of the ecosystem, the change in flooding’s timing, duration, and magnitude will affect the floodplain forests in two ways. First of all, the forest structure will change due to the negative effects of flooding on seed dispersal, seedlings and tree growth. For example, small tree will decrease from forest while the older trees’ size will increase. Secondly, the forest diversity will decrease because of the lack of adaptation in trees to cope with the increased severity of the floods.
For better understanding of the effects of increase in flooding magnitude on floodplain forest, more research is needed on plant density, diversity and average size. Also, we need to know the degree of change in the flooding regimes, to help determine management approaches. IDH provides a much better perspective tool to understand what is happening in the Mississippi River’s floodplains. According to that these floodplains would have much better diversity if the ecological disturbances would be intermediate as oppose to frequent or rare. As the paper established that the condition in Mississippi River is not an intermediate condition but a shift in its pattern hence the ecological disturbance, flooding in this case, is becoming more frequent and destroying the biodiversity in the floodplains.
Achenbach, Luciana, and Hans Brix. ‘Can Differences In Salinity Tolerance Explain The Distribution Of Four Genetically Distinct Lineages Of PhragmitesAustralis In The Mississippi River Delta?’.Hydrobiologia 737.1 (2013): 5-23. Web.
Cairns, J. Jr. “Quantification of biological integrity.” 1977. Pages 171–187 in R. K. Ballentine and L. J. Guarria, editors. Integrity of Water, Report Number 0055–001–010680–1, U.S. Environmental Protection Agency, Office of Water and Hazardous Materials, Washington, D.C.
Cosgriff R.J.,. Nelson J.C, Yin Y., 2007, Floodplain Forest Response to Large-Scale Flood Disturbance,Transactions of the Illinois State Academy of Science, Vol. 100, #1, pp. 47-70
Craine, S.I. &Orians, C.M. 2006, “Effects of Flooding on Pitch Pine (Pinusrigida Mill.) Growth andSurvivorship”, Journal of the Torrey Botanical Society, vol. 133, no. 2, pp. 289-296.
De Jager, N.R., Thomsen, M. Yin, Y. 2012, “Threshold effects of flood duration on the vegetation andsoils of the Upper Mississippi River floodplain, USA”, Forest Ecology and Management, vol. 270, pp. 135-146.
Drew M.C., 1997, Oxygen Deficiencyand Root Metabolism: Injury and Acclimation UnderHypoxia and Anoxia, Annu. Rev. Plant Physiol. Plant Mol. Biol. 1997. 48:223–250
Gibbs J and Greenway H. (2003) Mechanisms of anoxia tolerance in plants. I. Growth, survival and anaerobic catabolism. Functional Plant Biology 301–47.
Glenz, C., Schlaepfer, R., Iorgulescu, I. &Kienast, F. 2006, “Flooding tolerance of Central European tree and shrub species”, Forest Ecology and Management, vol. 235, no. 1, pp. 1-13.
Gravatt, D.A., Kirby, C.J., 1998. Patterns of photosynthesis and starch allocation in seedlings of four bottomland hardwood tree species subjected to flooding. Tree Physiol. 18, 411–417.
Herrera, Ana et al. ‘Changes with Seasonal Flooding in Sap Flow of the Tropical Flood-Tolerant Tree Species, Campsi and ra Laurifolia’. Trees 22.4 (2008): 551-558. Web.
Ishida, Shinya et al. ‘Effects of Flooding and Artificial Burning Disturbances on Plant Species Composition in a Downstream Riverside Floodplain’. Ecological Research 23.4 (2007): 745-755. Web.
Junior d S, U.M., de CarvalhoGonçalves, J.F. &Fearnside, P.M. 2013, “Measuring the impact of flooding on Amazonian trees: photosynthetic response models for ten species flooded by hydroelectric dams”, Trees, vol. 27, no. 1, pp. 193-210.
Kabrick, J.M., Dey, D.C., Van Sambeek, J.W., Coggeshall, M.V. & Jacobs, D.F. 2012, “Quantifying flooding effects on hardwood seedling survival and growth for bottomland restoration”, New Forests, vol. 43, no. 5, pp. 695-710.
Knox, James C. ‘Floodplain Sedimentation in the Upper Mississippi Valley: Natural versus Human Accelerated’. Geomorphology 79.3-4 (2006): 286-310. Web.
Knutson, M.G., Hoover, J.P., and Klass, E.E. The importance of floodplain forests in the Conservation and management of geotropically migratory birds in the Midwest. 1996. USDA Forest Service Publication.
Kozlowski TT (1984) Plant responses to flooding of soil. Bioscience 34:162-167
Kozlowski, T. T. ‘Responses of Woody Plants to Flooding and Salinity’. Tree Physiology 17.7 (1997): 490-490. Web.
Kozlowski, T.T., Pallardy, S.G., 1997. Growth Control in Woody Plants. Academic Press, San Diego
Lau, C.L., Smythe, L.D., Craig, S.B. & Weinstein, P. 2010, “Climate change, flooding, urbanisation andleptospirosis: fuelling the fire?”, Transactions of the Royal Society of Tropical Medicine and Hygiene, vol. 104, no. 10, pp. 631-638.
Lubinski, Kenneth. “Floodplain River Ecology and the Concept of River Ecological Health.” Ecological Status and Trends of the UMRS, 1998 U.S. Fish and Wildlife Service. “Chapter 3: Affected Environment.” Upper Mississippi River Refuge Final Environmental Impact Statement / Comprehensive Conservation Plan. 2006. Web.
Lukac, Martin, MargusPensa, and Gabriel Schiller. ‘Tree Species’ Tolerance To Water Stress, Salinity And Fire’. Forest Management and the Water Cycle (2010): 247-261. Web. 9 Apr. 2015.
Martin, W. H., S. G. Boyce & A. C. Echternacht, 1993. Biodiversity of the Southeastern United States: Lowland Terrestrial Assemblages. John Wiley & Sons, New York
McKevlin, M.R., D.D. Hook and W.H. McKee, Jr. 1995. Growth and nutrient use efficiency of water tupelo seedlings in flooded and well-drained soils. Tree Physiol. 15:753—758
McQuilkin, Robert A., and Ralph A. Musbach. ‘Pin Oak Acorn Production on Green Tree Reservoirs in Southeastern Missouri’. The Journal of Wildlife Management 41.2 (1977): 218. Web.
Middleton, B., 1995, the role of flooding in seed dispersal: Restoration of cypress swamps along the Cache River, IL, Department of Plant Biology. Southern Illinois University at Carbondale
Moore, J.E., Franklin, S.B. &Grubaugh, J.W. 2011, “Herbaceous plant community responses tofluctuations in hydrology: Using Mississippi River islands as models for plant community assembly1”, The Journal of the Torrey Botanical Society, vol. 138, no. 2, pp. 177-191.
Niklas, Karl J., Jeremy J. Midgley, and Richard H. Rand. ‘Tree Size Frequency Distributions, Plant Density, Age and Community Disturbance’. Ecology Letters 6.5 (2003): 405-411. Web.
Pettit, N.E., and R.H. Froend. ‘Variability in Flood Disturbance and the Impact On Riparian Tree Recruitment In Two Contrasting River Systems’. Wetlands Ecology and Management 9.1 (2001): 13-25. Web. 9 Apr. 2015.
Pezeshki SR (1993) Differences in patterns of photosynthetic responses to hypoxia in flood-tolerant andflood-sensitive tree species.Photosyn 28:423–430
Pinter, Nicholas et al. ‘Trends in Flood Stages: Contrasting Results from the Mississippi and Rhine River Systems’. Journal of Hydrology 331.3-4 (2006): 554-566. Web.
Polomski, J., Kuhn, N., 1998. Wurzelsysteme.Haupt, Bern
Rappaport, O. J. “What constitutes ecosystem health?” Perspectives in Biology and Medicine. 1989. 33:120–132.
Roberts JKM, Callis J, Jardetzky O, Walbot V, Freeling M. (1984b) Further evidence that cytoplasmicacidosis is a determinant of flooding intolerance in plants. Plant Physiology 77492–494.
Romano, S.P. 2010, “Our current understanding of the Upper Mississippi River System floodplainforest”, Hydrobiologia, vol. 640, no. 1, pp. 115-124.
Sahney, S., M. J. Benton, and H. J. Falcon-Lang. ‘Rainforest Collapse Triggered Carboniferous Tetrapod Diversification InEuramerica’. Geology 38.12 (2010): 1079-1082. Web.
Sellin A (2001) Hydraulic and stomatal adjustment of Norway spruce trees to environmental stress. TreePhysiol 21:879–888
Sparks, R.E., Nelson, J.C. & Yin, Y. 1998, “Naturalization of the Flood Regime in Regulated Rivers”,Bioscience, vol. 48, no. 9, pp. 706-720.
Vartaptian ,B.B, Jacksonn, M.B. (1997) Plant adapations to anaerobic stress. Annals of botany 79, n3-20
Wilkinson, David M. ‘The Disturbing History of Intermediate Disturbance’. Oikos 84.1 (1999): 145. Web.
Time is precious
don’t waste it!