Key Concepts and Terms: Unit 7
You are much more informed about ecological concepts, but there is (always) more to learn. In particular, you need to be able to do the following:
Remember that you can refer back to all the chapters on plant and animal diversity in your Woodlot Biodiversity field guide.
You are much more informed about ecological concepts, but there is (always) more to learn. In particular, you need to be able to do the following:
- Explain some of the causes and consequences of forest diversity.
- Define the Intermediate Disturbance Hypothesis (IDH) and discuss how it might influence forest biodiversity.
- Examine the concepts of ecosystem function and services.
- Discuss modern ecosystem management tools such as adaptive management.
Remember that you can refer back to all the chapters on plant and animal diversity in your Woodlot Biodiversity field guide.
Intermediate Disturbance Hypothesis (Connell, JH. 1978 Diversity in tropical rain forests and coral reefs. Science 199:1302 -1310): The Intermediate Disturbance Hypothesis (IDH) predicts that the highest species richness will occur at an intermediate level of intensity or frequency of natural disturbance. This is because low levels of disturbance do not create many habitats to support a variety of species, whereas high levels of disturbance will eliminate many habitats that support species diversity. Communities are constantly changing in response to varying levels of disturbance. For example, when a single tree falls in a woodlot it creates a “gap” that has higher levels of light, which support a new community of species. These species are optimally suited to high light conditions in which they can establish themselves and out-compete other shade tolerant species. Large, infrequent, disturbances are often catastrophic and include disturbances such as floods, forest fire, hurricanes and volcanic activity. A woodlot may be transformed by a severe fire into an open field dominated by herbs and grasses. A less severe fire may transform a maple woodlot into one that is dominated by ash and popular seedlings. Natural disturbances are very important in shaping landscapes and influencing ecosystem processes. The figure below is Figure 1 from Connell 1978).
Last week we introduced the concepts of "ecosystems" and "ecosystem processes". This week we add two related concepts:
Ecosystem Function: Ecosystem function includes the exchange of energy and nutrients among plants, animals and thier environment. For example in the woodlot there is a great deal of carbon in the form of branches and leaf litter that is decomposing and producing biomass. There is a host of organisms including insects, bacteria and fungi that literally keep the logs and branches from piling up on the woodlot floor. Explore the campus natural area GigaPans for evidence of fungi on logs and sticks.
For example, here is some fungus on decaying log on the floor of the Goose Walk woods in the Arboretum. In the Dairy Bush there is a small stand of choke cherry that has an infection of pathogenic fungus (black knot fungus; Apiosporina morbosa). You can see this fungal infection here or trace it backwards in time using the Dairy Bush TimeMachine. You can read more about the black knot fungus here.
Ecosystem Service: Ecosystem Services refers to the processes within ecosystems that provide fundamental resources such as water, clean air or even the decomposition of waste products. Woodlots provide many services such as carbon recycling (e.g., carbon dioxide in the air converted into biomass in wood and leaves), animal waste filtering from adjacent farms and filtering of watersheds.
Adaptive Management: Adaptive management utilizes ecosystem management as a tool to alter the functioning of an ecosystem. This approach is designed to test hypotheses about the functioning of the ecosystem and often starts with identifying uncertainties, and then establishing the methodologies to test hypotheses concerning those uncertainties. This approach allows ecosystem managers to use hypothesis testing as a tool to learn about the ecosystems while managing for certain predicted outcomes. For example a woodlot manger may want to change a conifer-dominated woodlot into one that is dominated by hardwoods. This approach might include a management strategy built on hypotheses concerning the propagation and growth requirement of specific hardwood species in response to manipulating light from the existing conifer canopy. There are several steps typically utilized in an iterative approach to the adaptive management cycle that are outline in the figure below. Below is a key figure explaining “Adaptive Management” from Bell et al. (2008).
For further information about adaptive management, read the paper by Bell et al. 2008 as an example of implementing a forest research strategy based on an adaptive management approach. (Bell, F.W., J.A. Baker, G. Bruemmer, J. Pineau and A. Stinson. 2008a. The Canadian Ecology Centre – Forestry Research Partner- ship: Implementing a research strategy based on an active adaptive management approach. For. Chron. 84(5): 666–677)
Ecosystem Function: Ecosystem function includes the exchange of energy and nutrients among plants, animals and thier environment. For example in the woodlot there is a great deal of carbon in the form of branches and leaf litter that is decomposing and producing biomass. There is a host of organisms including insects, bacteria and fungi that literally keep the logs and branches from piling up on the woodlot floor. Explore the campus natural area GigaPans for evidence of fungi on logs and sticks.
For example, here is some fungus on decaying log on the floor of the Goose Walk woods in the Arboretum. In the Dairy Bush there is a small stand of choke cherry that has an infection of pathogenic fungus (black knot fungus; Apiosporina morbosa). You can see this fungal infection here or trace it backwards in time using the Dairy Bush TimeMachine. You can read more about the black knot fungus here.
Ecosystem Service: Ecosystem Services refers to the processes within ecosystems that provide fundamental resources such as water, clean air or even the decomposition of waste products. Woodlots provide many services such as carbon recycling (e.g., carbon dioxide in the air converted into biomass in wood and leaves), animal waste filtering from adjacent farms and filtering of watersheds.
Adaptive Management: Adaptive management utilizes ecosystem management as a tool to alter the functioning of an ecosystem. This approach is designed to test hypotheses about the functioning of the ecosystem and often starts with identifying uncertainties, and then establishing the methodologies to test hypotheses concerning those uncertainties. This approach allows ecosystem managers to use hypothesis testing as a tool to learn about the ecosystems while managing for certain predicted outcomes. For example a woodlot manger may want to change a conifer-dominated woodlot into one that is dominated by hardwoods. This approach might include a management strategy built on hypotheses concerning the propagation and growth requirement of specific hardwood species in response to manipulating light from the existing conifer canopy. There are several steps typically utilized in an iterative approach to the adaptive management cycle that are outline in the figure below. Below is a key figure explaining “Adaptive Management” from Bell et al. (2008).
For further information about adaptive management, read the paper by Bell et al. 2008 as an example of implementing a forest research strategy based on an adaptive management approach. (Bell, F.W., J.A. Baker, G. Bruemmer, J. Pineau and A. Stinson. 2008a. The Canadian Ecology Centre – Forestry Research Partner- ship: Implementing a research strategy based on an active adaptive management approach. For. Chron. 84(5): 666–677)