BIOL 1020H Lecture Notes - Lecture 10: Nitrification, Arisaema Triphyllum, Denitrification

55 views2 pages

erinmink51

17 Dec 2015

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Supporting studies have been cited to form our hypothesis and prediction for this research. This implies that each particular species have a certain level of sensitivity or tolerance to nitrogen which makes it a determining factor on biodiversity. Another factor that needs to be address in this experiment are the various forms nitrogen can affects diversity of plants species. One of the factors considered is that biological processes are influenced by prevailing climatic conditions along with the physical and chemical properties of a particular soil (lamb, fabian, fernandez, & kaiser, 2014). In our experimental study, it is considered that the prenanthes altissima is more tolerant in low nitrogen compared to. Arisaema triphyllum thus allowing the prenanthes altissima to dominate over the arisaema triphyllum on biodiversity. However, the arisaema triphyllum which is more reliant on nitrogen will have more advantage on the cfh site in terms of biodiversity.

Related Questions

can you please give me a response for this Article(type the anwer)

When a soil dries out, this has a negative impact on the activity of soil bacteria. Using an innovative combination of state-of-the-art analysis and imaging techniques, researchers at UFZ have now discovered that fungi increase the activity of bacteria in dry and nutrient-poor habitats by supplying them with water and nutrients. The ability of fungi to regulate drought stress in soil and thus sustain ecosystem functions is an important insight in the context of climate change.

Many fungi spread through the soil with a fine network of thin filaments known as hyphae. In their search for water and nutrients the hyphae grow in different directions, constantly enlarging the network. Once found, water and nutrients are absorbed and transported through the hyphae, allowing them to be supplied to parts of the fungal network in dry or nutrient-poor areas of the soil. But it isn't only the fungus itself which benefits from the transport of material through the hyphal pipelines: bacteria, too, are kept supplied with the water and nutrients they need to thrive. This has now been demonstrated by a team of UFZ researchers in a study recently published in the journal Nature Communications. "We've suspected for a long time that fungi play an important role in the soil moisture budget," says UFZ environmental biotechnologist Prof. Matthias KÃ¤stner. "Now, using secondary ion mass spectrometry techniques (NanoSIMS and ToF-SIMS) from the ProVIS research platform at UFZ, we've finally obtained experimental evidence."

As part of their investigations, the researchers closely examined the transport of water, substrates and nutrients through the microscopically small hyphae of fungi. They grew the fungi on a culture medium of water, glucose and nitrogen-containing nutrients. The fungal hyphae had to pass through a dry, nutrient-free zone in order to grow through into a new area containing the culture medium. The inhospitable transition zone contained spores of the common soil bacterium Bacillus subtilis. Spores are inactive stages of Bacillus that form when there is insufficient water, food and nutrients available for bacterial growth. The bacteria go into a kind of dormant stage, from which they only awake once the environmental conditions are more favourable for living again.

In the experiment, these conditions were indeed improved by the growth of the fungi: "As the fungal hyphae grew through the dry zone, the bacterial spores germinated and we noticed clear microbial activity," says UFZ environmental microbiologist Dr. Lukas Y. Wick. "The fungi obviously improved the environmental conditions for the bacteria and woke them from their slumber, like Sleeping Beauty." But what exactly happens at a chemical level when fungal hyphae grow in direct proximity to bacterial spores? To answer this question, the researchers 'labelled' the water, glucose and nitrogen-containing nutrients in the culture medium in advance with stable isotopes. If these substances were transferred from the fungus to the bacteria, they could be detected using the isotopic marker and the NanoSIMS method, with nano-scale spatial resolution. "The NanoSIMS method reveals the distribution of elements and isotops and therefore allows us to observe metabolic processes," KÃ¤stner explains. "As it turns out, we did find the stable isotopes of the labelled water, glucose and nitrogen-containing nutrients in the cell mass of the bacteria -- which could only have come from the fungi."

This study has given the UFZ researchers another important insight into fungi and their important function in soils. Fungi serve as pumping stations and pipelines for water, substrates and nutrients and can colonise inhospitable locations, making them habitable for bacteria -- and thus stimulate microbial activity in the soil. In previous work the researchers have already shown that fungal hyphae act as a kind of fungal highway for bacteria, allowing them to move around, and provide a hotspot for bacterial gene transfer. Wick continues: "The results of this latest study demonstrate once again that, through their interaction with bacteria, fungi play a significant, previously underestimated role in the soil ecosystem."

If a soil is contaminated with pollutants, for example, bacteria can break them down. But if the soil is too dry, the degradation processes will come to a standstill. "If the drought period lasts for a limited time, fungi have a stabilising effect and can keep soil processes going. This could be important specifically with regard to the impacts of climate change, if the ratio of dry to moist areas of soil dramatically increases," says KÃ¤stner. In future investigations, the researchers therefore intend to look even more closely at soil as a true ecosystem. "We want to carry out soil experiments under different environmental conditions and find out what influence fungal growth has on the breakdown of pollutants," says Wick. He adds: "It's important to have a better understanding of the role of fungi in the soil ecosystem. Only when we know how soil works can we respond to changes, for example those caused by climate change, with informed decisions."

What is a method that some ecologists have proposed to protectspecies from extinction in the face of global climate change?

natural attenuation
assisted migration
bioremediation
mitigation
adaptive management

Why is it usually not possible to restore a community to itspre-altered state?

It is not always possible to determine the kinds of speciesthat populated a community.
Invasive species compromise restoration.
Climate change complicates restoration.
Evolutionary trajectories cannot be predicted.
All answers are correct.

How is ecological restoration different from restorationecology?

It considers cultural and societal concerns.
It does not rely on ecological principles.
It cannot be predicted.
It does not involve manipulation of the environment.
All answers are correct.

What is the goal of assisted migration?

to help species respond to climate change
to help species learn new seasonal migration routes
to help migrating species avoid human-made structures
to help native species tolerate restoration efforts
All answers are correct.

Which of the following might serve to enhance habitat in arestoration project?

a dead log in a stream
a concrete water control structure in an estuary
removal of a dam
an artificial nesting box
All answers are correct.

Biologists want to restore a region that experienced stripmining. How will bacteria assist in the restoration?

They will restore the biotic parts of a community.
They will enhance adaptive management.
They will remove harmful metals.
They will improve revegetation.
They will remove the source of the disturbance.

A barge has leaked a small amount of oil in the middle of LakeMichigan. What might be the best solution to clean it up?

Add molasses to stimulate bacterial action.
Leave it alone.
Introduce engineered bacteria.
Add microorganisms not normally found in the lake.
Launch a comprehensive restoration effort.

Before deciding on an appropriate restoration strategy for aparticular degraded ecosystem, which information would be LEASTimportant to have?

the goals of the restoration, in terms of biodiversity andecosystem functioning
the degree to which the ecosystem has been degraded whencompared to a reference ecosystem
the types of species that were present before thedegradation
the social, political and economic constraints on therestoration
None of the answers are correct.

A biologist works to restore habitat during a restorationproject. Which of the following might serve to enhance thehabitat?

a dead log in a stream
a concrete water control structure in an estuary
removal of a dam
an artificial nesting box
All answers are correct.
10.
Restoration ecologists want to restore a landscape to itsoriginal state before humans arrived and altered it, but they donot know what species of plants lived there historically. What isthe best alternative?
Import plants from other ecosystems at the same latitude.
Bioremediate the soil.
Use plants growing nearby.
Use assisted migration.
Let nature take its course.

11.

Biologists begin collecting native seeds in a seed bank in aregion that experienced considerable alteration. Describe thebenefits of taking this action for the future.

It is important to collect samples of native seeds for culturalpurposes.
Biologists can use the seeds to restore other regions atsimilar latitudes.
If the region is heavily altered, it may take time and multiplesteps to restore the region. Collecting the seeds while they areavailable ensures that the biologists can use them later in therestoration process.
The see bank will promote the assisted migration of plants fromhabitats made unsuitable by climate change.
All answers are correct.

12.

Although disturbance is often thought of as a detriment tonatural ecosystem functioning, one type of disturbance, fire, isoften used to restore ecological communities. In what way(s) canfire restore ecological communities?

Fire is an effective way to "clean the slate" of the ecosystemby burning plants and sterilizing the soil so that appropriatemitigation and bioremediation plans can be implemented.
In ecosystems where fire is a natural periodic event, fire cankill many non-native plant species while leaving native speciesless influenced.
Fire can suppress the growth of competitive dominant plants,such as shrubs and trees, increasing the diversity of certainecosystems.
All answers are correct.
None of the answers are correct.