Plant-Soil Interactions with Fire

Plant-Soil Interactions With Fire

In this blog I will be discussing plant-soil interactions that are caused by fire. Aldo Leopold is considered to be the godfather of conservation and has left a major impact on the wildlife techniques that we use today. Leopold had five wildlife management techniques. These techniques were an axe, cow, plow, match, and a gun.  Aldo Leopold once said, “Fire has always been part and parcel of the evolutionary background of our present species in many regions.” Prescribed fires are commonly used to promote plant growth and set back succession. Wildfires are fires that are burning out of containment and can have various intensities. While some people view fire as a detrimental thing to the environment, it can be very beneficial. For example, the Great Smoky Mountain wildfire destroyed many homes and businesses but it could result in the betterment of some of the ecosystems that were burned. Many plant species rely on fire for their existence. These plants have many adaptations that help them survive these fires. A few of these adaptations include serotinous cones and thick bark. Fires also clear debris from the soil’s surface allowing for seeds to be in contact with bare mineral soil. Fire can have a major impact on the environment in many ways. If you have never seen an area that has recently been burned, then you are in for a treat. What was once a place that was not anesthetically pleasing and covered in plant litter becomes a magnificent field of green plants emerging from the ground. Fire impacts plants and their soils in the environment through the change of plant communities.

Before starting this blog, I would like to inform my readers that this could quite possibly be my last blog post. It has been a great journey throughout my years, but I have accepted a position at Brewster’s Services Group to further my career in wildlife and fisheries.

A major factor that affects species abundance and diversity is plant-soil feedback (Klironomos, 2002). Some of the factors that promote plant invasion success are higher resource availability and reduced competition (Davis et al. 2000). Fire is a type of disturbance that has been suggested to facilitate plant success by interacting with belowground soil biota (Blumenthal, 2005). Do you see the problem here? While fire as the ability to promote desired species establishment, it also has the potential to create an environment that is beneficial for invasive species. Fire doesn’t just interact with the soil it can also create an environment that is beneficial for invasive species. The intensity of the fire plays a major role in determining how it impacts the ecosystem. Low intensity fires have a minor effect on organic matter and soil structure, however high intensity fires can create temperatures high enough to break down soil aggregates (Prosser & Williams 1998). Fire can also affect physical and chemical soil properties. Fire intensity and frequency have an effect on the amount of alteration of abiotic and biotic factors (Debano et al. 1977). Fire can increase the amount of elements in the soil. Some of the elements that fire increases are K, Mg, Ca, and Na. The amount of phosphorus in the soil following a fire is variable. Fire can also increase the amount of soil exchangeable Ca^2+ and Mg^2+ (Murphy et al. 2005). On the other hand, a more intense fire can cause a significant change of woody vegetation on the ecosystem (Langevelde et al. 2003). In 1966, the use of prescribed burning was eliminated at Tall Timbers Research Station in Tallahassee, Florida. After the first fifteen years of fire exclusion, the changes in wildlife abundance and vegetation were obvious. The amount of groundcover decreased from 85% to 21%, while the canopy cover increased from 43% to 91% (Engstrom et al. 1984).

            Fires can be related to plant invasion. Even-though fires can improve plant invasion success; studies have shown that fire can suppress the spread and establishment of invasive plants (D’Antonio, 2000). Fire can be very beneficial to ecosystems, but it has the potential to dramatically change the soil biota (Gonzalez-Perez et al. 2004). Smith performed a study that showed the abundance of exotic species was much higher in unburned sites than in sites that were burned every year. A study performed by D’Antonio showed that prescribed burning decreased the amount of invasive species in 20% of his trials. He looked at two types of disturbances. A Type 1 disturbance removed only the aboveground flora, while a Type 2 disturbance removed the aboveground and belowground biota. His study showed that Type 1 disturbances facilitated plant invasion and Type 2 disturbances suppressed plant invasion.

Figure 1 shows the relative competitive ability that is required for successful plant invasion under a disturbance that removed the aboveground and belowground biota.

Figure 1.

Relative competitive ability required for successful invasion under type II disturbances. The horizontal axis represents natural mortality d. (a) Different curves represent different values of the intensity δ. As δ increases, the threshold value of relative competitive ability increases, implying a stricter invasion condition. γ is fixed at 0.4. (b) Different curves represent different values of the disturbance probability γ. 

So why do we care about the plant-soil interactions with fire? Some studies have shown that some invasive plants can have a less negative soil feedback than native species (Inderjit et al. 2010). If an area is disturbed by something like fire, then there is a chance that that area can come back in invasive plants. And if an area consists of invasive plants, then it is very difficult to eradicate those plants. It is suggested that plant invasion can be facilitated by weakened negative soil feedback in the new habitat (Turnbull et al. 2010). Physical disturbances, such as fire, are important factors that can affect the success of plants (D’Antonio, 2000). Fire can enhance or suppress the distribution and abundance of plant species (Lockwood et al. 2007). If prescribed fire is used correctly, it has the potential to promote desired plant species instead of invasive species.

My research on plant-soil interactions with fire has given me a better understanding of how fire impacts plants and soils. I have concluded that these interactions can be attributed to three key points. 1) Fire can create conditions that are beneficial to many plant species 2) Fire can create changes in the soil that can help promote invasive species 3) Fire intensity can influence plant-soil interactions.

Fire impacts the environment through the changes in plant communities. Fire can have a major impact on the environment in both positive and negative ways. The use of fire has been used as a management tool for hundreds of years. I have personally used prescribed fires to burn around 2,000 acres, and I have seen how many ecosystems strive after the application of fire. However, wildfires can create a problem for the environment. I have found through my research that the changes in plant communities are related to fire.

Literature Cited

D’Antonio C., Mooney R., Hobbs A. Fire, plant invasions, and global changes (Eds.), Invasive Species in a Changing World, Island Press, Washington, DC (2000), pp. 65–93

J.N. Klironomos Feedback with soil biota contributes to plant rarity and invasiveness in communities Nature, 417 (2002), pp. 67–70

Inderjit, W.H. Van der Putten Impacts of soil microbial communities on exotic plant invasions Trends in Ecology & Evolution, 25 (2010), pp. 512–519

Fukano, F. Tackiki, Y. Soil disturbances can suppress the invasion of alien plants under plant–soil feedback. Ecological Modelling, 260 (2013), pp. 42-49

Debano, L.F., Dunn, P.H. & Conrad, C.E. (1977): Fire's effects on physical and chemical properties of chaparral soils. In: Proceedings of the Symposium on the Environmental Consequence of Fire and Fuel Management Ecosystems. ESDA Forest Service General Technical Report. WO-3, 65- 74.

 

Murphy, J. D., et al. "Wildfire effects on soil nutrients and leaching in a Tahoe Basin watershed." Journal of Environmental Quality 35.2 (2006): 479-489.

 

J. Lockwood, M. Hoopes, M. Marchetti Invasion Ecology Blackwell Publishing Ltd, Oxford (2007)

 

M.A. Davis, J.P. Grime, K. Thompson Fluctuating resources in plant communities: a general theory of invisibility.Journal of Ecology, 88 (2000), pp. 528–534

 

D. Blumenthal Ecology. Interrelated causes of plant invasion Science (New York, N.Y.), 310 (2005), pp. 243–244

 

Prosser, Ian P., and Lisa Williams. "The effect of wildfire on runoff and erosion in native Eucalyptus forest." Hydrological processes 12.2 (1998): 251-265.

 

J.a. González-Pérez, F.J. González-Vila, G. Almendros, H. Knicker The effect of fire on soil organic matter—a review. Environment International, 30 (2004), pp. 855–870

Competition With Fire

Plant-Plant Interactions With Fire

In this blog I will be discussing the interactions between plants and fire. Aldo Leopold is considered to be the godfather of conservation and has left a major impact on the wildlife techniques that we use today. Leopold had five wildlife management techniques. These techniques were an axe, cow, plow, match, and a gun.  Aldo Leopold once said, “Fire has always been part and parcel of the evolutionary background of our present species in many regions.” Prescribed fires are commonly used to promote plant growth and set back succession. Wildfires are fires that are burning out of containment and can have various intensities. While some people view fire as a detrimental thing to the environment, it can be very beneficial. For example, the Great Smoky Mountain wildfire destroyed many homes and businesses but it could result in the betterment of some of the ecosystems that were burned. Many plant species rely on fire for their existence. These plants have many adaptations that help them survive these fires. A few of these adaptations include serotinous cones and thick bark. Fires also clear debris from the soil’s surface allowing for seeds to be in contact with bare mineral soil. Fire can have a major impact on the environment in many ways. If you have never seen an area that has recently been burned, then you are in for a treat. What was once a place that was not anesthetically pleasing and covered in plant litter becomes a magnificent field of green plants emerging from the ground. Fire impacts plant-plant interactions by allowing more sunlight to reach the ground and by decreasing competition.

Many plant species have different light tolerance. Some species may be shade intolerant while others may be shade tolerant. It is up to the management objectives to determine what species composition that they want. If an early successional/shade intolerant ecosystem is desired, then prescribed fire can be a very useful tool to achieve those conditions. According to the Oxford Dictionary, competition refers to the “negative effects caused by the presence of neighbors, usually by reducing the availability of resources.” Plants generally need water, light, phosphorus, and nitrogen to survive. If plants don’t have these resources or other plants are using up most of those resources, then those plants will most likely die off. One of the most important factors that control plant communities is competition (Bond et al. 1997).  Fire helps reduce plant competition by eliminating the majority of the mid-story and understory of the ecosystem, which creates an increase in light penetrating to the forest floor. A more intense fire can cause a significant change of woody vegetation on the ecosystem (Langevelde et al. 2003). In 1966, the use of prescribed burning was eliminated at Tall Timbers Research Station in Tallahassee, Florida. After the first fifteen years of fire exclusion, the changes in wildlife abundance and vegetation were obvious. The amount of groundcover decreased from 85% to 21%, while the canopy cover increased from 43% to 91% (Engstrom et al. 1984).  Fire can indirectly reduce the potential of future mortality through decreasing competitive and self-shading pressure (Zimmermann et al. 2010). Fire can also decrease plant cover, biomass and density of grass layers (Drewa et al. 2001). Fire is used in many savannas and grasslands to stimulate plant growth and control woody plant densities (McPherson, 1995).

So why do we care about plant-plant interactions with fire? Plants need resources such as water, light, phosphorus, and nitrogen to survive. Fire can be used to remove plants and open up space on the ground. This open space can then be colonized by plants of the same or different species (Begon et al. 1990). Fire can stimulate many plant species creating enhanced seed germination, flowering, and seedling recruitment (Bond et al. 1997). Fire can help certain ecosystems strive in many ways. Not only does fire have the ability to increase herbivory, it can influence plant survival and growth (Crawley, 1983). Many plant species depend on fire for reproduction, and without the presence of fire many of these plants could become extinct. A few of these plant species include longleaf pines, wiregrass, and giant sequoias. It is very important to understand that many plant and animal species depend on fire. If an ecosystem has less competition, then many fire dependent plants can colonize the area. Fire has the ability to set back succession and promote plant growth. Fire can be used in a variety of ways such as agriculture, woodlands, and fields. Fire has also been used as a management tool to restore native grasslands. Fire is a very useful tool that can be used to reduce plant competition and boost plant growth. The species composition that emerges after a fire can also benefit wildlife.

A study performed by Zimmermann et al. showed that increased standing dead biomass was associated with increased tuft mortality through the presence of fire (Figure 1). Fire reduced the standing dead biomass and created a less competitive environment.

Figure 1.

Predicted tuft mortality depending on neighbor abundance quantified by the living basal area of neighbors (NA_LBA), standing dead biomass (SDB) and fire.

My research on plant-plant interactions with fire has given me a better understanding of how fire impacts plants. I have concluded that these interactions can be attributed to three key points. 1) Fire can remove debris and litter from the ground that allows for plants to establish. 2) Fire intensity is crucial for determining desired species composition. 3) Fire can help reduce competition by killing some plants and allowing sunlight to reach the ground. Fire impacts the environment through the changes in plant communities and reducing plant competition. Fire can have a major impact on the environment in both positive and negative ways. The use of fire has been used as a management tool for hundreds of years. I have personally used prescribed fires to burn around 2,000 acres, and I have seen how many ecosystems strive after the application of fire. However, wildfires can create a problem for the environment. I have found through my research that the changes in plant communities and competition are related to fire.

Literature Cited

Engstrom, R.T., R. L. Crawford and W. W. Baker. 1984. Breeding bird populations in relation to changing forest structure following fire exclusion: A 15-year study. Wilson Bull. 96: 437-450.

Van Langevelde, Frank, et al. "Effects of fire and herbivory on the stability of savanna ecosystems." Ecology 84.2 (2003): 337-350.

P.B. Drewa, K.M. Havstad Effects of fire, grazing, and the presence of shrubs on Chihuahuan desert grasslands Journal of Arid Environments, 48 (2001), pp. 429–443

G.R. McPherson The role of fire in the desert grasslands M.P. McClaran, T.R. van Devender (Eds.), The Desert Grassland, The University of Arizona Press, Tucson (1995), pp. 130–151

 Zimmermann J., Higgins S., Grimm V. Grass mortality in semi-arid savanna: The role of fire, competition and self-shading. Perspectives in Plant Ecology, Evolution and Systematics. 12.1 (2010), pp. 1-8.

W.J. Bond Fire R. Cowling, D. Richardson, S. Pierce (Eds.), Vegetation of Southern Africa, Cambridge University Press, Cambridge (1997), pp. 421–446

Begon, M., J. L. Harper, and C. R. Townsend. "Ecology: Individuals." Populations and (1990).

Crawley, Michael J. Herbivory. The dynamics of animal--plant interactions. Blackwell Scientific Publications, 1983.

Plant-biotic Interactions with Fire

Plant-Biotic Interactions With Fire

In this blog I will be discussing the interactions between plants and fire. Aldo Leopold is considered to be the godfather of conservation and has left a major impact on the wildlife techniques that we use today. Leopold had five wildlife management techniques. These techniques were an axe, cow, plow, match, and a gun.  Aldo Leopold once said, “Fire has always been part and parcel of the evolutionary background of our present species in many regions.” Prescribed fires are commonly used to promote plant growth and set back succession. Wildfires are fires that are burning out of containment and can have various intensities. While some people view fire as a detrimental thing to the environment, it can be very beneficial. For example, the Great Smoky Mountain wildfire destroyed many homes and businesses but it could result in the betterment of some of the ecosystems that were burned. Many plant species rely on fire for their existence. These plants have many adaptations that help them survive these fires. A few of these adaptations include serotinous cones and thick bark. Fires also clear debris from the soil’s surface allowing for seeds to be in contact with bare mineral soil. Fire can have a major impact on the environment in many ways. If you have never seen an area that has recently been burned, then you are in for a treat. What was once a place that was not anesthetically pleasing and covered in plant litter becomes a magnificent field of green plants emerging from the ground. Fire impacts the biotic factors in the environment through the change of plant consumption and reduced competition.

The presence of fire is very important for herbivory. The great Aldo Leopold went on to say, “fire may well be the single most important factor in determining what animal and vegetable life will thrive in many areas.” Fire can help improve both the nutritional and quantity of food available to herbivores. This increase in food abundance can aid in the increase of carrying capacities, growth rates, and reproduction for many herbivores (Mellars, 1976).  The use of fire and grazing plays a vital role in both the maintenance and establishment of savannas and grasslands (Milchunas et al. 1988).  When fire occurs in an ecosystem, herbivores typically select recently burned areas (Vinton et al. 1993). Fire isn’t just used for forests and grasslands, but for agriculture as well. The severity of herbivore grazing is correlated to the intensity of the fire. If there is a large amount of grazing on an area there tends to be less fuel load for the fire, which will cause a less severe impact on the ecosystem. On the other hand, a more intense fire can cause a significant change of woody vegetation on the ecosystem (Langevelde et al. 2003). In 1966, the use of prescribed burning was eliminated at Tall Timbers Research Station in Tallahassee, Florida. After the first fifteen years of fire exclusion, the changes in wildlife abundance and vegetation were obvious. The amount of groundcover decreased from 85% to 21%, while the canopy cover increased from 43% to 91% (Engstrom et al. 1984).

So why do we care about the plant-biotic interactions with fire? Animals need food to survive. In North America, two very important influences on the function and structure of grasslands are herbivore grazing and fire (Vinton et al. 1993). Ecosystems that have experienced a fire generally have a robust amount of vegetation in the understory. This in increase in plant abundance in the understory allows for animals to eat them more easily. An increase in plant consumption by animals can allow for them to have a higher carrying capacity, increased growth rates, and more successful reproduction. The increased amount of beneficial plant material located on the forest floor can also be attributed to the lack of plant competition that is caused by fire. Herbivore numbers and fire are two ways that landowners can meet their desired objectives (Levich et al. 2009). Sometimes land managers need to cut down valuable trees in order to increase sunlight to the forest floor. This is one of the management tools that is used that most of the public does not like. Most hunters want to hunt around oak trees and they think that cutting some of those trees down is a stupid idea, but what about the other eight or nine months that those trees aren’t producing mast? Fire helps reduce plant competition by eliminating the majority of the mid-story and understory of the ecosystem, which creates an increase in light penetrating to the forest floor. So if you were a deer, would you rather have acorns to eat three or four months out of the year or would you rather have a robust amount of grasses, forbs, and seedlings to eat? Fire doesn’t just increase the amount of forage, it also provides specific habitat that some animals need to survive.

           

Animals need food, water, cover, and shelter to help then strive in an ecosystem. The presence of fire has the ability to create early successional habitat that some species desire. There are many species that depend on fire. A few of these species are white-tailed deer, wild turkey, northern bobwhite, red-cockaded woodpecker, and many other birds (Brennan et al. 1998). The Northern Bobwhite Quail is a perfect example of a species that depends on fire. Leopold stated that the northern bobwhite “was undoubtedly evolved in an environment that was always subject to occasional burning” Quail are also known as the “fire bird” and need fire to help create the necessary habitat that they need. Quail require fire every one to two years to help restore their habitat (Graves, personal communication).

It is very important to understand that many wildlife species need fire to be successful. The use of fire has decreased over the years, and as a result, so have the wildlife species that depend on them (Table 1). It is because of the lack of fire that many species are in decline, threatened, and even endangered (Table 1). The following table was produced from the findings that Brennan et al. 1998 found in their study of fire-dependent wildlife species without the presence of fire. 

Table 1. Terrestrial vertebrates from southern pine forests and savannas that have affinities for habitats maintained by frequent fire.

                            Species                                                   Current Status

Gopher tortoise	Threatened
Greater prairie-chicken	Endangered
Northern bobwhite	Declining
Red-cockaded woodpecker	Endangered
Bachman’s sparrow	Declining
Sherman’s fox squirrel	Declining
Eastern indigo snake	Threatened
Florida grasshopper sparrow	Endangered

 “Endangered and threatened status according to U.S. Fish and Wildlife Service listed vertebrate species index, January 31, 1998. Declining status determined from various sources.

My research on plant-biotic interactions with fire has given me a better understanding of how fire impacts plants and animals. I have concluded that these interactions can be attributed to three key points. 1) Many ecosystems and wildlife species depend on fire. 2) The use of fire has decreased, and as a result, many fire-dependent species are struggling. 3) Herbivores can influence the intensity of the fire by reducing the fuel load.

Fire impacts the environment through the changes in plant consumption and reduced plant competition. Fire can have a major impact on the environment in both positive and negative ways. The use of fire has been used as a management tool for hundreds of years. I have personally used prescribed fires to burn around 2,000 acres, and I have seen how many ecosystems strive after the application of fire. However, wildfires can create a problem for the environment. I have found through my research that the changes in plant consumption and competition are related to fire.

Literature Cited

Mellars, Paul. "Fire ecology, animal populations and man: a study of some ecological relationships in prehistory." Proceedings of the Prehistoric Society. Vol. 42. Cambridge University Press, 1976.

Milchunas, D. G. , O. E. Sala , and W. K. Lauenroth . 1988. A generalized model of the effects of grazing by large herbivores on grassland community structure. Am. Nat. 132:87–106.

Vinton, M. A. , D. C. Hartnett , E. J. Finck , and J. M. Briggs . 1993. Interactive effects of fire, bison (Bison bison) grazing and plant community composition in tallgrass prairie. Am. Midl. Nat. 129:10–18.

Van Langevelde, Frank, et al. "Effects of fire and herbivory on the stability of savanna ecosystems." Ecology 84.2 (2003): 337-350.

Levick, Shaun R., et al. "The relative influence of fire and herbivory on savanna three-dimensional vegetation structure." Biological Conservation 142.8 (2009): 1693-1700.

Brennan, L.A.; Engstrom, R.T.; Palmer, W.E. 1998. Whither wildlife without fire?. Transactions of the 63rd North American Wildlife and Natural Resources conference; 1998 March 20-25; Orlando, FL. Washington, DC: Wildlife Management Institute: 402-414.

Graves, Chris. Personal Communication. 2016.

Engstrom, R.T., R. L. Crawford and W. W. Baker. 1984. Breeding bird populations in relation to changing forest structure following fire exclusion: A 15-year study. Wilson Bull. 96: 437-450.