The Importance of Restoring Plant Communities

Ecological restoration of plant communities is meant to restore lost biodiversity, primarily through recovering the original plant communities rather than increasing the number of species.  The number of species associated with degraded environments would in turn also have to be decreased.  Restoration efforts of plant communities include less expensive methods through modifying abiotic factors, such as soil and water.  More expensive methods involve biotic modifications that include reseeding or replanting native species from local sources, and removing invasive species through mechanical means or herbicides. 

Protecting the environment is the government’s responsibility.  The omnibus C-38 bill passed by the Harper government negatively affected various aspects of environmental protection.  The Canadian Environmental Assessment Act was replaced with a new act limited to fish and aquatic species, and the Species at Risk Act for birds.  The Canadian Environmental Assessment Agency was also affected, having only 45 days after receiving an application to decide if an assessment is required.  Environmental assessments are not required; instead the minister is given the power to decide.  Another act negatively affected was the Canadian Environmental Protection Act.  Current 1 year limit permits for disposing waste at sea can be renewed up to 4 times, and the 3 and 5 year limits protecting species from industrial waste will have no limits. 

There are many important reasons for ecosystems restoration including helping threatened or endangered species, lessening the effects of climate change, restoring natural resources, or simply to mitigate the extinction of experience for humans.  In order for this to happen however, new acts which increase the reach of restoration efforts have to be passed.  This is the responsibility of the new generation of scientists and politicians. 

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Negative Effects of Agriculture on the Environment

Agriculture is a vital part of our current way of life, however current agricultural practices have had numerous negative effects on the environment and surrounding habitats.  Forests have to be cleared in order to provide space for agriculture.  This destroys the forest ecosystems and also contributes to climate change due to forests acting as carbon sinks.  Other agricultural processes release greenhouse gases including carbon dioxide as well.

The removal of trees can cause water to evaporate faster due to the lack of shade, and in addition to the other pollutants, negatively affect the water quality.  The lower water quality then affects the rest of the ecosystem that relies on the water, as well as humans.  Uneven irrigation can result in under irrigation of soil some areas which causes increased salinity, killing the plants.  Over irrigation can cause more nutrient and chemical runoff, which also affects water quality.   Water can also erode the topsoil, causing a decline in the soil quality.  Other factors which negatively affect the soil quality include chemicals from pesticides and improper waste disposal.

In order to reduce the impacts on the surrounding environment, sustainable agricultural practices need to be implemented.  Soil is the most important aspect in ensuring crop growth.  Methods to preserve soil quality include installing windbreaks to reduce wind erosion, low-till or no-till farming to avoid water evaporation and retain nutrients, and composting also helps to reintroduce nutrients back into the soil.  Another method includes reducing the use of chemical fertilizers and growing a number of different crops in the same field so that the legumes can naturally restore nutrients in the soil each season.  This also helps with monocultures of crops, which are susceptible to diseases.  Measures need to be put into place to ensure there can be enough food produced as human populations increase and the need for available farmland increases as well. 

Kudzu: An Invasive Species With Useful Properties

Kudzu, also known as Japanese arrowroot, is an invasive plant species originating from East and Southeast Asia.  In its native environment kudzu is a useful plant, it helps the ecosystem by resisting erosion and increasing nutrient content in the soil.  Kudzu can also be used for animal feed, its long vines used to weave baskets, and the plant fibers used for making paper.  Kudzu is edible, in parts of East Asia the roots are ground up and used as starch to make mochi, and the flowers are also used to make jelly.  Kudzu has also been used in traditional medicine, producing tea from the roots that contains isoflavones. 

However, since the intentional introduction of Kudzu to the US for the purposes to stop soil erosion in the 1930s, the plant has become an invasive species.  Kudzu vines spread rapidly and covers the area around them, killing other plants by blocking their access to the Sun.  Since then, the plant has been found in most areas in the South Eastern US and has been found on the Canadian shores of Lake Erie in 2009.  Kudzu has also been found in Australia, New Zealand, Italy, and Switzerland.  

In order to clear Kudzu completely, the root crown of the plant has to be removed otherwise the plant can regrow.  This can be done by hand or mechanically, or by using chemical herbicides.  An experimental fungal herbicide also appears to be effective in removing Kudzu without harming other plants.  Although burning is not advised, repeated consistent harvesting to replete the nutrients is also effective.  Kudzu is invasive in the wild, but in its natural habitat the plant provides many useful functions for the ecosystem and for human uses. 

The Effects of Climate Change on the Tundra

Climate change has caused numerous observable impacts on the environment.  The increased temperatures have had the greatest effect on areas that are generally cold, such as the tundra biome.  In Antarctica, the rate of the loss of ice mass from 1992 to 2006 has increased by 59% in West Antarctica, and increased by 140% in the Antarctic Peninsula (Rignot et al., 2008).  General impacts in tundra biomes include the decrease in height and size of deciduous shrubs and graminoids, a decrease in moss and lichen cover, and decreased species diversity.  This was caused by a 1-3°C increase in air temperatures, and the effects could be observed after only two years.

These changes in temperatures cannot be attributed to the Earth’s natural climate fluctuations alone.  Climate change has been primary caused by humans releasing large amounts of carbon dioxide into the atmosphere which trap more heat from the Sun, raising temperatures through a process called the greenhouse effect.  Other anthropomorphic impacts that have also contributed to climate change include pollution, urban expansion into natural areas, poor management practices, and rapid increases in human populations. 

If temperatures continue to rise, irreversible damage will be done to various ecosystems around the world.  Many species will be forced to relocate to more suitable conditions or face the risk of extinction, and biomes such as the tundra will lose more of their biodiversity.

Something I Remembered from Plant Bio

Pollen grains are produced by seed bearing plants:  angiosperms and gymnosperms.  They are microgametophytes that contain the genetic material of male plants from the sporophyte generation.  The pollen grains are encased in two layers; the extine is the outer later and is composed of sporopollenin, a complex polymer, and the inner layer called the intine.  The walls of the pollen grain protect it from drying out and are able to resist chemical degradation so the pollen can successfully be transported to the stigma of female plants.  Pollination can be mediated by animal pollinators which include bees, ants, butterflies, beetles, hummingbirds, and other small vertebrates; pollination can also be conducted by abiotic factors such as wind or water.

Pollen identification allows the reconstruction of past plant abundances from pollen fossils due to their resilience.  In addition, identification of pollen on their animal pollinators could help ecologists determine the distribution and dispersal ability of the plant species.  Furthermore, identifying pollen would be helpful to those with pollen allergies.  Pollen can be indentified in labs by using safranin to dye the pollen, followed with microscopy. 

            The pollen lab in BIOL2010 was interesting but very tedious.  It was very difficult to see the pores and furrows on the outer layer of the pollen grains under the microscope.  It would often be hard to distinguish the features described on the guide, and identification would eventually devolve into a guessing game rather than a scientific method.  The material on the pollen lab ended up not being on the lab exam, so in the end the whole thing felt somewhat useless.  It ended up being memorable, however.