[Photo: Northern goshawk (Accipiter gentilis). Source: Wikipedia. Photo taken by Norbert Kenntner. CC-by-SA-3.0 Unported license.]
Killing Trees
to
Restore Forests
(and savannahs)
----------------
Burning Issues in Forest Restoration:
Fire-Dependent Ecosystems
[Photo: Understory fire in pine forest. Source: U.S. Forest Service. Image in public domain.]
"It is the most beautiful region I ever remember to have seen in any part of the world. A vast forest of gigantic pines, intersected frequently with open glades, sprinkled all over with mountains, meadows, and wide savannahs, and covered with the richest grasses, was traversed by our party for many days."
-- (Lt. Edward Beale quoted by Bell, 1870)"The time has come for science to busy itself with the earth itself. The first step is to reconstruct a sample of what we had to begin with."
-- Aldo Leopold, 1934----------------
Part 1 - Status of Global Forests
- Interactive Maps: Exploring Global Forests
- Deforestation Around the World
Part 2 - Restoring Ponderosa Pine Forests
- The "Southwest Model"
- Restoration of Low-Elevation Dry
Montane Forest
- Ecology of Dry Montane Forest
Part 3 - Climate Change, Western Forests,
and Fire Risk
Part 4 - Recreating Tree Spatial Patterns
Part 5 - Classics by the Beetles: (We love trees, yeah,
yeah, yeah)
Part 6 - Video: Flying Through Keyholes: Goshawks
in Forests
Part 7 - The Snag in Our Theory...
Part 8 - Are Lizards Toast?
- Lizard Reproduction and Fire in Ponderosa
Pine Forests
Part 9 - Cemeteries and Ecological Restoration:
The Gentner's Fritillary
Part 10 - In The News:
- Cats, Climate Change, and Whale Tales
- Bird Extinctions on Islands in the Bahamas
- Worried About Your Next Science Test?
Don't!!! Why You're Better Than Average
(hopefully...)
Part 11 - Laboratory Assignment: Case Study of
Cavity-Nesting Birds in Pine / Oak Forests
Part 12 - Study Questions, Discussions, and
Research Assignments
Part 13 - More In-Depth (optional)
Study Objectives:
In this unit, we will explore forest restoration with a focus on the ecology of dry montane forests in the western U.S. You know, the millions of acres of forests currently burning and destroying human communities out West...
You will learn how Euro-American settlement rapidly changed the structure and disturbance regimes of the ponderosa pine forests and what the consequences are for the ecological health and function of these iconic forests. You will also learn about the projected changes in western forests resulting from global climate change, and how attempts to restore spatial tree structure and fire influences biological diversity of wildlife in the region. After completing this unit, you should be able to describe all of the primary (major) anthropogenic and ecological elements that shape our ponderosa pine forests and many other fire-dependent forests.
Key Terms / Concepts:
Ponderosa pine restoration; pine savanna; surface fuels; ladder fuels; cattle/sheep grazing; fire suppression effects; shade-tolerant conifers; crown fires; oak savanna; fire-prone ecosystems; fire severity; silviculture; successional habitats; reference conditions; episodic tree recruitment; Northern Rockies; montane forests; Northern Goshawks; sagebrush lizards; Western skink; Mountain Bluebirds; cavity-nesting birds.
Part 1 - Status of Global Forests
Forests and forest resources are of immense and inestimable value to humanity and all life on Earth. While someone somewhere has undoubtedly put a dollar value on forest resources, such calculations are inevitably flawed and deficient, because without forests we would lose a large portion of all species on Earth and catastrophically alter global ecology - which by the way, we are in the process of doing!
"We" means a burgeoning global population of 7.1+ billion people, simply could not remotely maintain our existence in our current condition without forests. Consequently, forests are an integral part of all life on Earth.
Here's a thought for you. We might want to pay some attention to forest conservation and restoration. Just a suggestion....
Because of their practical use for "food, fuel, and fiber" forests have supported humanity from the dawn of our existence and evolution. Forests cover about 30-31% of the world's land surface (Earth Policy Institute 2012). While forests that were once cut or burned now are regrowing in some areas, particularly in the northern hemisphere due to reforestation efforts, overall, there is a continuing decline in global forests, which greatly exacerbates global carbon emissions.
In some areas, major tropical forests (e.g., the Amazon) are being decimated at truly alarming rates, triggering the concern that forest loss could create ecological tipping points in which destroyed ecosystems cannot be restored and which may create uncontrollable, runaway climate conditions.
Systematic remote sensing estimates of forest land use change indicate that annual global forest losses were greater in 2000-2005 than in 1990-2000 (FAO & JRC 2012). Global forest area decreased by nearly 2 percent between 1990 to 2005 with the greatest losses occurring in tropical areas, particularly in South America and Africa. Given the large contribution of deforestation to carbon emissions and global climate change, how do we restore forests for the many diverse reasons fundamental to a sustainable environment?
Interactive Maps: Exploring Global Forests
To examine the extent and general status of global forests from 2000-2012, visit the interactive map, Global Forest Change, published by the University of Maryland.
You may use the menu choices in the right hand side bar of the above web site to explore different facets of forest cover and change in forest cover in the world at different times.
Deforestation Around the World
[Photo: Deforestation for oil palm plantations in Sumatra, Indonesia. Source: Wikipedia. CC-by-SA-2.0 license.]
Let's begin our studies of forest restoration by looking at a good overall summary of the subject of deforestation. While it may take 10-15 minutes for you to carefully read this overview of deforestation, it is a worthwhile beginning for our studies and provides a concise description of factors important to understanding the ecology and need for restoration of global forests.
Part 2 - Restoring Ponderosa Pine Forests
[Photo: Ponderosa pine (Pinus ponderosa) identification. Source: Wikipedia. CC-by-SA-3.0-Unported license.]
[Photo: Range map of ponderosa pine subspecies in the western United States. Source: Wikipedia. Image in public domain. Author: Robert Z. Callaham. Pinus ponderosa: A Taxonomic Review With Five Subspecies in the United States. Pacific Southwest Research Station. Research Paper PSW-RP-264.]
[Photo: Ponderosa pine on Fritz Frey Ranch, West Fork Valley Creek, 8 miles west of Arlee, Montana. Source: Forest History Society. CC-by-NC-2.0 license.]
Let's begin our more detailed studies of forest restoration right in our own backyard, the western United States. To begin, we'll examine the basic factors influencing the low elevation, dry forests characterized by the iconic ponderosa pine (Pinus ponderosa) or "p-pine" as you'll commonly hear it described.
The "Southwestern Model" of Restoring Ponderosa Pine Forests
Some of the most widely cited materials describing the history and current ecology of ponderosa pine forests originates from the well-studied southwestern United States in areas of New Mexico and Arizona. One of several widely-cited papers describes how ponderosa pine forests have been greatly restructured and degraded by Euro-American land use:
Allen, C.D. et al. 2002. Ecological restoration of southwestern ponderosa pine ecosystems: a broad perspective. Ecological Applications 12(5):1418-1433.
source: WSU e-Journals in Search [IT]
Note: Use the 2nd source listed in the WSU library for online access.Targeted Reading Assignment (the following specific sections only): Abstract; Introduction; Background; then skip ahead to - The importance of heterogeneity in time and space (p. 1421); Use of the natural range-of-variability concept for restoration (p. 1422); Biodiversity considerations (p. 1423); then skip ahead and just look at the individual numbered items (1-16) in italics under Principles for Ecological Restoration (i.e., you do not have to read this whole section, just look at the numbered items in italics to see what is involved; then finish with the section: Ecological Perspectives on Several Forest Restoration Approaches (p.1428-1429).
After reading these selected portions of this article, you should be able to understand and describe the historical conditions of ponderosa pine forests prior to Euro-American settlement and how these have changed drastically due to logging, intensive early grazing, and fire suppression.
It should be fairly clear to you how ecological factors such as fire intervals, episodic tree recruitment events, removal of competing understory vegetation by heavy grazing, and altered natural fire regimes resulted in current forest conditions. You should also understand the current forest restoration issues, which include changing global climate, the risk of catastrophic stand-replacing fires, risks to people and communities now living in forested areas, and the "conundrum" of how and whether we can return controlled, low-intensity fire to these forests while still allowing them to act as a carbon sink to help reduce global emissions.
Can we have our cake (products from restored forests) and eat it too (i.e., not contribute to global carbon emissions)?
Truthfully, we don't know completely, but western forests may be carbon sinks initially because of increased growth, but then potentially become carbon emitters later under high warming scenarios as climate change increases.
Next, let's look at how the ecology of ponderosa pine forests in the northern Rockies and other regions differs from this "southwestern model".
Restoration of Low-Elevation Dry Montane Forests
[Photo: Ponderosa pine in the Sierra Nevada lower montane forest in Yosemite Valley. Source: Wikipedia. Photo by Jodie Wilson. CC-by-2.0 Generic license.]
"...the dry forests of the Northern Rockies differ from those of the Southwest in several ecologically significant ways, raising questions about the appropriateness of applying the southwestern model to these forests. In the Northern Rockies, a wetter, cooler climate leads to less frequent fires, even in pure stands of ponderosa pine. The admixture of Douglas-fir and western larch creates different conditions for burning, and the complex terrain of steep mountain slopes results in fires that burn fiercely in some places and hardly at all in others. The resulting “mixed-severity fire regime” historically yielded a complex mosaic of patches of large, old trees and young, recovering forest." --(Crist et al. 2009)
[Graphic: "Map of the different regimes of natural burning in natural ecosystems of the United States. Colors denote both the frequency of wildfires and their style of burning. Before European colonization, wildfires occurred most frequently in the tan, yellow, blue, pink, and light green areas." Source: Wikipedia. Author: Jim Menakis, from the source: Brown, James K.; Smith, Jane Kapler. 2000. Wildland fire in ecosystems: effects of fire on flora". (http://www.treesearch.fs.fed.us/pubs/4554) Gen. Tech. Rep. RMRS-GTR-42-vol. 2 40,56-68. Dept. of Agriculture, Forest Service, Rocky Mountain Research Station. In public domain.]
In contrast to the frequent, low-severity ground fires occurring in southwestern ponderosa pine forests, the dry montane forests in the Northern Rockies may more often experience a mixed-severity, mid- to late summer fire regime. Greater variation in the types of fires means that in the Northern Rockies and elsewhere a mosaic of burns often were created ranging from areas experiencing high-intensity fires with some crown fires to lower and moderate-intensity fires, but still including patches of unburned trees.
Ecology of Dry Montane Forest
Let's look at the ecology of ponderosa pine forests in these more northern areas, beginning with an excellent two-page description of the typical forest composition, structure, and distribution on the landscape (see: Download Restoring-Low-Elevation-Dry-Forests-Rocky-Mountains).
Assignment: Just read pages 4 and 5 of this report, and note Table 1 on page 5, indicating common understory species in the dry montane forest.
Part 3 - Climate Change, Western Forests, and Fire Risk
[Photo: Fall tree colors in the Rocky Mountains. Photo by Andrew Kratz. Source: US Dept. of Agriculture. CC-by-2.0 Generic license.]
We can describe and predict the likely effects of climate change on western forests in two sentences from a report by the Pacific Northwest Research Station:
"Climate warming may first show up in forests as increased growth, which occurs as warmer temperatures, increased carbon dioxide and more precipitation encourage higher rates of photosynthesis.
The second way that climate change may show up in forests is through changes in disturbance regimes - the long term patterns of fire, drought, insects, and diseases that are basic to forest development." -- Western Forest, Fire Risk, and Climate Change (2004)
These two sentences are the punch lines for climate change and fire risk in western forests as we head into the deeply troubling future world of global climate change. If you remember the few simple details of these two sentences, you will understand the essence of projected climate change impacts in the Pacific Northwest and many areas of western forests.
But let's look at the projections for climate change in slightly greater detail to reinforce these conclusions in our minds and see how these projections may be useful to fire and forest managers.
The following Science Update of the Pacific Northwest Research Station nicely encapsulates and graphically depicts a number of future changes that we may expect in forests, savannas, shrub-steppe ecosystems in North America (see download page: Issue 6 (2004) Western Forest, Fire Risk, and Climate Change).
"In the Western United States, the conundrum would be how to balance carbon storage with reducing fuels and fire risk.
We can try to enforce the ecological status quo, which will be increasingly difficult. We can sit back and let change happen. Or, we can manage for climate change."
Assignment: For now, just download this pdf report and read the front page summary and the "Key Findings" box in green on the second page.
In particular, in the Key Findings box, pay attention to factors such as the spread of juniper into grasslands, expansion of woody vegetation, increased rainfall, but with dry summers, and the issue of fires and long-term carbon storage in natural ecosystems (to mitigate climate change).
Later, we'll direct your attention to some other specific places in this publication in our study questions listed at the end of this unit.
Part 4 - Recreating Tree Spatial Patterns
As we have briefly seen from the introductory material covering the ecology of western forests, one of the major approaches to forest restoration is to use mechanical thinning (i.e., cutting) to return dense forests through a series of steps to a stage which resembles their historical condition of less dense, more widely spaced, mature trees. Recreating the spatial structure of these historical forests is often done by mapping the cut stumps and still living mature trees that pre-dated recent forest changes.
We can reconstruct the historical spatial distribution because of the potentially long life of mature ponderosa pine trees (e.g., 100-300+ years). By examining the growth history of long-lived trees through their tree rings, forest ecologists can reconstruct recent climate, growth patterns, and historical fire conditions.
Restoration Issue: Why is it important to study and reconstruct historical spatial patterns of trees on different landscapes instead of just cutting and creating an arbitrary pattern of relatively even tree spacing?
Let's look at the introduction only and some of the color photographs of a recent journal paper reviewing and summarizing 50 studies on tree spatial patterns:
Larson, A.J. and D. Churchill. 2012. Tree spatial patterns in fire-frequent forests of western North America, including mechanisms of pattern information and implications for designing fuel reduction and restoration treatments. Forest Ecology and Management 267:74-92.
source: WSU e-Journals through Search[IT] Note: Use the 2nd source listed for online access
Targeted Reading Assignment: Introduction only; Fig. 2 - relict ponderosa pine forest in the Bob Marshall Wilderness, Montana; Fig. 3 - pine-oak woodland, California; Fig. 4 - old-growth sugar pine, California; Fig. 5 - Wenatchee Forest, Washington; Fig. 6 - mixed forest, Montana; Fig. 9 - a uniformly thinned stand on U.S. Forest Service lands in northern California.
Part 5 - Classics by the Beetles:
(We love trees, yeah, yeah, yeah)
[Photo: Mountain pine beetle (Dendroctonus ponderosae). Source: William M. Ciesla, Forest Health Management International, USDA Forest Service.]
"There are three major categories of disturbance known in ponderosa pine forests in our study area: fire, mountain pine beetle (Dendroctonus ponderosae) and associated blue-stain fungus (Ophiostoma spp.), and windthrow. These agents are capable of acting as stand- replacing events, and potentially leave long-term evidence of their presence. Mountain pine beetles carry blue-stain fungus on their bodies, and trees are essentially inoculated with the fungus when the beetles pen- etrate the cambium to lay their eggs." (Ehle and Baker 2003)
While mountain pine beetles are native insects and a natural part of forest ecology, serious outbreaks are increasing because of dense forests with large expanses of trees in unhealthy condition. The USDA Forest Service has a leaflet which aptly describes the ecology and consequences of mountain pine beetle infestations when they reach outbreak proportions over large expanses (see the open source: Mountain Pine Beetle). While looking through this Forest Service leaflet, you should note the association of the mountain pine beetle with the blue stain fungus.
[Photo: Blue stain fungus (Grosmannia clavigera) in cross section of tree. Source: Wikipedia. Source: US Forest Service. Image in public domain.]
Part 6 - Video: Flying Through Keyholes:
Goshawks in Forests
[Photo: Northern goshawk. Source: Wikipedia. Photo by Steve Garvie. CC-by-SA-2.0 Generic license.]
The Northern Goshawk is one of a number of wildlife species closely associated with forested environments and typically is found in areas of more mature forests that are disturbed less by humans. Consequently, it is one species that affects forest management actions in the western U.S. Because we seldom see the behavior of most species we study and discuss, we thought it would be interesting for you to see how well their flight behavior is adapted to chasing and capturing prey in wooded environments, which requires great ability to maneuver through openings in trees and branches.
Part 7 - The Snag in Our Theory...
[Photo: Northern flicker (Colaptes auratus) excavating a cavity in a tree snag. Source: Washington Department of Fish and Wildlife.]
Part 8 - Are Lizards Toast?
(Lizard Reproduction and Fire in Ponderosa Pine Forests)
[Photo top: Sagebrush lizard (Sceloporus graciosus). Source: Wikipedia. Author: Geographer. CC-by-SA-2.5 Generic license. Photo middle: Blue ventral patches on a male southern sagebrush lizard. Source: Wikipedia. Photo by Jurvetson (flickr). CC-by-2.0 Generic license. Photo bottom: Coronado skink, a subspecies of the Western skink (Plestiodon skiltonianus) juvenile. Source: Wikipedia. Photo by Nathancourt. CC-by-SA-3.0 Unported license.]
As western ponderosa pine forests have become more dense and lost habitat heterogeneity on small scales (i.e., patches and variations in habitat on local small scales of measurement), biodiversity of characteristic species often has declined. To see how ecological restoration of ponderosa pine forests may influence two common species of lizards in the western U.S., we'll look at the abstract and introduction only for the following article:
Germaine, S.S. and H.L. Germaine. 2003. Lizard distributions and reproductive success in a ponderosa pine forest. J. Herpetology 37(4):645-652.
source: WSU e-Journals through Search[IT]
Targeted Reading Assignment: Abstract and Introduction only.
Part 9 - Cemeteries and Ecological Restoration: Gentner's Fritillary
[Photo top: Close up of Gentner's Fritillary (Fritillaria gentneri). Photo bottom: Habitat of Gentner's Fritillary. Source: U.S. Forest Service. Photo by Tom Kaye, Institute for Applied Ecology.]
Many of us might not readily equate cemeteries with any facet of ecological restoration or forest restoration, but such habitats often contain species that have managed to escape destruction by cultivation for farming and urban development. Sometimes small patches of "left over" or overlooked habitats can contain valuable species and biological diversity.
Assignment:
The Klamath-Siskyou Wildlands Center has a nice description of the ecology of the Gentner's Fritillary.
See the interesting history of discovery of this beautiful plant by looking at the paragraph in the section, Did you know?, on the second page of this report by the Oregon Dept. of Agriculture.
Ponderosa Pine Woodlands
The guide by the Oregon Department of Fish and Wildlife, called Strategy Habitat: Ponderosa Pine Woodlands, provides a concise overview of the ecology and conservation status of ponderosa pine habitats, including the challenges to restoring historical habitat conditions.
Part 10 - In The News:
Cats, Climate Change, and Whale Tales
[Photo: Beluga whale (Delphinapterus leucas). Source: Wikipedia. Photo by Steve Snodgrass. CC-by-2.0 Generic license.]
- The Liberty Voice and other news organizations are reporting that scientists have discovered the parasite (Toxoplasma gonddi) responsible for "kitty litter disease" in beluga whales. Scientists suspect that several factors may be involved, including the increase in domestic cats kept by Inuit natives and increasing temperatures related to climate change and the thawing/warming occurring in the Arctic.
See news story:Arctic Whales Infected With Domestic Cat Parasite.
[Photo: Northern crested caracara (Caracara cheriway). Source: Wikipedia. Author: naturespicsonline. License: Public domain.]
- See news story: The first human settlers on islands caused extinctions.
[Photo: The sun. Source: Wikipedia. Photo by
NASA/SDO. In the public domain.
- Worried About Your Next Science Test? Don't!!! You're Better Than Average (hopefully...)
Well, you needn't worry about doing as badly as the so-called average American when asked some basic science questions in a 2012 survey by the National Science Foundation.
They report that 25% of Americans thought that the sun revolves around the Earth.... Yes, you heard that correctly!
Moreover, only 48% knew (or maybe wanted to admit) that "Human beings, as we know them today, developed from earlier species of animals."
My Take: The response to this second question could mix in people's religious views/opinions, so perhaps the results are not quite as clear as you might think for a supposed science question.
See ABC News:Quarter of Americans Convinced Sun Revolves Around Earth, Survey Finds.
Part 11 - Laboratory Assignment: Case Study of Cavity-Nesting Birds in Pine / Oak Forests
[Photo: Mountain bluebird male (Sialia currucoides). Source: Wikipedia. Photo by Elaine R. Wilson at NaturePicsOnline. CC-by-SA-2.5 Generic license.]
To prepare for your laboratory assignment, go to the web site of the American Bird Conservancy (ABC) and select one of these three Special Reports that interest you
NOTE: The American Bird Conservancy has a beautiful web site, but it is a little tricky to find the link to their "Special Reports."
To do so, on their web site, click on the "Special Reports" link at the bottom of the publications page that appears when you use the preceding link (see this screenshot from their web page).
Clicking on their Special Reports link will open up a window of icons for the following three reports and many other special reports. Then, you'll have to scroll through pictures of various report cover pages to find the three specific reports listed below, one of which you should select and use for our laboratory assignment):
1) Land Manager's Guide to Cavity-Nesting Bird Habitat and Populations in Ponderosa Pine Forests of the Pacific Northwest.
2) Land Manager's Guide to Bird Habitat and Populations in Oak Ecosystems of the Pacific Northwest (Part One and Part Two), or
3) Snags, Bark Beetles, and Cavity-Nesting Birds: Conservation and Management in Ponderosa Pine Forests of the Pacific Northwest.
Part 12 - Study Questions, Discussions, and Research Assignments
Answer the following questions off-line (i.e., save your responses in a word processor) and then, when you are finished, "cut and paste" and post your replies in the comment box below this entry.
Part 1 - Interactive Maps: Exploring Global Forests
Use the "Data Products" drop-down menu on the right side of the referenced web site in Part 1 to explore changes in global forests (and zoom in to any areas if you want). What are a few general things you discover about global forests that you could tell someone else after looking at this mapping system?
Part 2 - Restoring Ponderosa Pine Forests
After reading the assigned papers for this section (e.g., Allen et al. 2002), how would you in your own words, describe the historical and current condition of western ponderosa pine forests, with particular reference to the effects of: livestock grazing, logging, and fire suppression?
Why might biodiversity likely decline in response to current conditions in ponderosa pine forests?
If you saw a ponderosa pine forest that had a lot of Douglas fir and / or Juniperus (juniper) species in it, what might you conclude?
What is the general prescription (i.e., management treatments) for restoring ponderosa pine forests in terms of recreating more natural historical conditions in them?
Why do fire regimes (i.e., fire intervals, or fire return intervals) tend to differ between ponderosa pine forests in the southwestern U.S. (i.e., New Mexico and Arizona) compared to other areas in the Northern Rockies and elsewhere?
Part 3 - Climate Change, Western Forests, and Fire Risk
Examine the figures for "Current climate" and "Future climate" (p. 4); "Vegetation Density" (p. 6); "Carbon source and Carbon sink" (p. 9); and "Current climate" and "Future climate" (p. 10), then answer:
What are the major predictions about changes in western forests as a resulting from climate change models?
Part 4 - Recreating Spatial Tree Patterns
In reference to the reading (Larson and Churchill 2012): Why is it important to study and reconstruct historical spatial patterns of trees on different landscapes instead of just cutting and creating an arbitrary pattern of relatively even tree spacing?
Part 5 - Classics by the Beetles...
What is the apparent mutualism (beneficial interaction or association) between the blue stain fungus and the mountain pine beetle?
Part 6 - Flying Through Keyholes
Why are Northern Goshawks well adapted to flying through small or strange-shaped openings?
Part 7 - The Snag in Our Theory...
In reference to this section on wildife use of snags, why might the use of "salvage logging" after fires or die-offs from mountain pine beetles be controversial?
Part 8 - Are Lizards Toast?
How are populations of our two common western lizard species affected by current conditions in ponderosa pine forests?
Part 9 - Cemeteries and Ecological Restoration
How does this very short piece on restoration of Gentner's Fritillary illustrate the importance of having people knowledgeable about plant ecology involved in conducting and monitoring ecological restoration efforts?
Part 10 - In the News
How do you think news articles, such as the story about Whale Tales and Cats, and the story about bird extinctions on islands in the Bahamas, can possibly relate to the subject of restoration ecology? [in other words, how do these stories potentially illustrate issues in restoration ecology?]
Part 11 - Laboratory Assignment: Case Study of Cavity-Nesting Birds in Pine / Oak Forests
Pick out one of the three identified reports on cavity-nesting birds by the American Bird Conservancy and review it carefully. Then select one of the bird species identified in that report and fire up your internet browser and do a little bit of independent research on this species.
Be sure not just to use a general google search, but rather look at google scholar and other publications and reports identified through more specific searches.
Then, in your own words and just a few short paragraphs (2-3-4?), how would you explain to the general public the importance of the indicated forest restoration efforts to the ecology and conservation of your selected bird species?
Due Date for Posting Answers: Tues. Oct. 13th (by midnight...)
Part 13 - More In-Depth (optional studies for those who are interested in additional detail)
(For the overachievers among us. And you know who you are....)
"Natural ecological disturbance creates habitats that are used by diverse groups of birds. In North America, these habitats or ecosystems include grasslands or prairies, shrublands, savannas, early succesional forests, and floodplains. Whereas the extent of all natural habitats has diminished significantly owing to ouright loss from agriculture and development, the suppression of disturbance by agents such as fire and flooding has led to further losses."
Brawn, J.D., S.K. Robinson, and F.R. Thompson III. 2001. The role of disturbance in the ecology and conservation of birds. Annual Review of Ecology and Systematics 32:251-276.
available from: WSU e-Journals through SEARCH [IT]
"As in Beale's day, an almost unbroken band of ponderosa pine forest 25 to 40 mi wide and nearly 300 mi long spreads across central and northern Arizona. With outliers in the higher mountains throughout the state, it constitutes one of the largest pine forests in North America....
...but the northern Arizona countryside is no longer the same land that Beale saw in 1857. Eighty-five years of white man's use and occupancy have profoundly altered the forest landscape."
Cooper, C.F. 1960. Changes in vegetation, structure, and growth of southwestern pine forests since white settlement. Ecological Monographs 30(2):129-164.
available from: WSU e-Journals through SEARCH [IT]
Literature Cited:
FAO & JRC. 2012. Global forest land-use change 1990–2005, by E.J. Lindquist, R. D’Annunzio, A. Gerrand, K. MacDicken, F. Achard, R. Beuchle, A. Brink, H.D. Eva, P. Mayaux, J. San-Miguel-Ayanz & H-J. Stibig. FAO Forestry Paper No. 169. Food and Agriculture Organization of the United Nations and European Commission Joint Research Centre. Rome, FAO.
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