U78 FE3 Quark - uwsp.edu · LEAF Guide • 7-8 UNIT Field Enhancement 3: Forest Diversity 211 MATERIALS LIST FOR EACH GROUP (8 TOTAL) • Copy of Student Pages 1A-B, Forest

NUTSHELLIn this lesson, students study and collect data on three components of diversity found within a forest: species, structural, and functionaldiversity. After comparing two types of forests,students discuss the value of diversity and therole it plays in a forest.

BACKGROUND INFORMATIONWisconsin has many different types of forests,including coniferous, deciduous, and mixed. Somespecific examples include, pine, aspen/birch,spruce/fir, maple/basswood, oak/hickory, andurban. These different forests show diversity in a variety of ways. This lesson explores species,structural, and functional diversity.

Biodiversity encompasses the variety andvariability of all life on earth. It is important tomaintaining the natural systems that support life. Wisconsin’s forests contain biodiversity and contribute to the overall biodiversity on theplanet. Biodiversity is generally measured inthree areas: species diversity, genetic diversity,and ecological diversity. This lesson exploresspecies diversity in a forest ecosystem, as wellas structural and functional diversity, which arecomponents of ecological diversity.

SPECIES DIVERSITYSpecies diversity can be assessed by measuringthe richness and evenness of the forest treecomposition. Richness is the number of differenttree species present in the forest. Evenness is a comparison of the number of individuals ofeach of those species. In order to have an evendistribution, the number of individuals in eachtree species needs to be close to even, notnecessarily perfectly even. To help explainrichness and evenness, refer to the example on page 212.

Field Enhancement 3: Forest Diversity

FIELDENHANCEMENT 3Forest Diversity

LEAF Guide • 7-8 UNIT210

OBJECTIVESUpon completion of this lesson, students willbe able to:• Define forest diversity.• Identify and measure components of three

types of diversity.• Compare and contrast different types of

forests with respect to diversity.

SUBJECT AREASScience

LESSON/ACTIVITY TIME• Total Lesson Time: 70 minutes • Time Breakdown:

Introduction.............5 minutesActivity, Part A ......20 minutesActivity, Part B ......20 minutesActivity, Part C ......20 minutesConclusion..............5 minutes

TEACHING SITEThis lesson can be done in any forested area.Ideally, there are a variety of tree species,sizes, and ages. It is recommended that thelesson be done at two contrasting sites, suchas a pine plantation and a mixed forest.

CLASSROOM LESSONCONNECTIONSThis lesson ties closely with Classroom Lesson2, Biodiversity and the Forest Connection.

Field Enhancement 3: Forest DiversityLEAF Guide • 7-8 UNIT 211

MATERIALS LISTFOR EACH GROUP (8 TOTAL)• Copy of Student Pages 1A-B, Forest

Diversity Data Sheets• Copy of Student Pages 2A-B, Forest

Diversity Data Sheet – Pine PlantationOR Student Pages 3A-B, Forest DiversityData Sheet – Mixed Forest. (Dependentupon the type of forest your students are collecting data from [see Teacherpreparation].)

• Forest Floor Sampling Square• Ruler• Tree ID book or dichotomous key• Clipboard or other writing surfaceFOR THE TEACHER• Nutrient Cycling poster (optional) • Plot markers (flagging, ribbon, stakes, etc.)• Tape measure (preferably 50' or 100')

TEACHER PREPARATION• Create eight plots at your teaching site. If time

permits, students can help prepare the plotsas part of the lesson. The same plots used inField Enhancement 2, Forest Mapping canbe used for this lesson. • Each plot should be 33' by 33' (which is

equivalent to 1/40th of an acre).• Mark the corners of the plots with flagging,

cones, or stakes.• Mark the center of the plots with a stake

containing a number, letter, color, etc.

• If you have only one type of forest for yourstudents to collect data in, make copies ofStudent Pages 2A-B, Forest DiversityData Sheet – Pine Plantation OR StudentPages 3A-B, Forest Diversity DataSheet – Mixed Forest for each of the eightgroups. Use the Data Sheet from theforest that is most different from the oneyour students are working in to representthe missing forest.

• Make or gather eight Forest Floor SamplingSquares. They can be 12" X 12" squares or circles with an open center like a picture frame. Sampling squares should be the samefor all students.

SAFETY PRECAUTIONSVisit the teaching site ahead of time to locateany hazards such as holes, hanging branches,protruding tree roots, poison ivy, etc. Encouragestudents to walk at all times. Consider these:• Are you in sight or earshot of students?• Are boundaries for students marked?• Have you set expectations for being out of

the classroom?• Do you have a whistle, first aid kit, insect

repellent, and sunscreen?• Is everyone dressed appropriately?

The level of richness is based on thenumber of different species present. Theevenness is determined by comparingthe numbers of each species present.NOTE: The measurements for richnessand evenness may be affected bysampling techniques. Imagine a forestwith 100 trees. Of those 100, 98 are red pine and two are white pine. Thisforest would have a richness level of two and an uneven composition.However, a poor sample may miss those white pines and lend a richness of one and an even composition.

Evenness

Even

Even

Uneven

Richness

1

4

4

3

Number ofSpecies

Total Numberof that Species

100

25, 25, 25, 25

22, 21, 26, 28

70, 28, 2

1

4

4

3

Field Enhancement 3: Forest Diversity LEAF Guide • 7-8 UNIT212

Duff Layer: Layer of the forest containingpartially decomposed organic material. Foundbeneath the litter layer on the forest floor.Evenness: A comparison of the number ofindividuals of each species in a forest.Forb Layer: Layer of the understory containingnon-woody plants.Forest Functions: Processes in a forestecosystem. These include nutrient cycling,photosynthesis, providing animal habitat, etc.Forest Services: The benefits that a forestprovides for humans. These may includerecreation, products, aesthetics, etc.Functional Diversity: The variety of functionsin a forest. Functions include nutrient cycling,photosynthesis, providing animal habitat, etc.Horizontal Structure: The distribution of forestlayers across the landscape.Litter Layer: Surface layer of the forest floorcomposed of leaves, twigs, needles, etc. withminimal decomposition.Microhabitat: A specific combination of habitatelements in an area that are needed by aparticular organism.

Overstory: The uppermost trees in a forest.Richness: A measure of the number ofdifferent species in a forest.Scat: A scientific term for animal feces. Shrub Layer: Layer of the understorycontaining woody plants with multiple stems.Species Diversity: The variety of speciespresent in a given area.Structural Diversity: The variety in thephysical organization of a forest. It has bothvertical and horizontal components.Structure: The horizontal and verticaldistribution of layers in a forest, includingheight, diameter, and species present.Understory: Forest vegetation present underthe overstory which can include trees, shrubs,and forbs.Vertical Structure: The distribution of forestlayers from top to bottom.

VOCABULARY

Even

Richness is a measure of the biodiversity thatexists in a forest. Evenness qualifies that value.One value without the other would be uselesswhen attempting to measure the true biodiversityof a forest. For example, a Wisconsin forest witha richness value of 5 might be a mixed hardwoodstand containing maple, ash, hickory, oak, andelm. This forest might be considered a naturalforest containing a variety of native animal andplant species. Yet, without the evenness value to further clarify the richness value of 5, theforest could actually be a red pine plantation that only has one or two trees of each of theother species mixed in with a large number of red pine trees. The evenness value helpsmeasure the abundance and distribution tree species, allowing a more completeunderstanding of the forest’s biodiversity.

STRUCTURAL DIVERSITYThe structural diversity of a forest includes both below and aboveground, vertical structureand horizontal structure. This lesson deals only with above ground diversity. A diversevertical structure includes an overstory and an understory, containing a tree, shrub, andforb layer. A diverse horizontal structure includesvariety in layers across the landscape. Forexample, two different types of forests withdifferent vertical layers adjacent to one anotherwould contribute to horizontal diversity.

The structural diversity of a forest has a direct effect on the diversity of animals within the forest. The more microhabitats a forest has,the greater the variety of animals the forest cansupport. The presence of standing dead trees andclimbing vines in a forest can enrich the forest’sstructural diversity by providing additional habitatsand pathways between the structural layers.

FUNCTIONAL DIVERSITYThe function of a forest refers to the processesthat occur within a forest ecosystem. A forest hasmany functions. These include cycling nutrients,producing oxygen, forming carbon-basedproducts (leaves, twigs, stems, bark, etc.), andproviding animal habitat. Forests also provideservices. Services are benefits that humans getfrom forests. They include things like recreationalopportunities, products, aesthetic value, etc. It is important to differentiate between forestfunctions and forest services.

Some forests are productive (grow very fast)while others are unproductive. Some cyclenutrients quickly, while others are slow. Somecontain a variety of animal habitats, and somehave relatively few. All of these are examples ofhow forests differ in their relative functions. Itwould be impossible for us to measure all of themany forest functions in one lesson. Instead, thislesson looks at the characteristics of the forestfloor to determine the relative rate at whichnutrients cycle.

FUNCTIONAL DIVERSITY – NUTRIENTCYCLINGThe forest floor is made up of fallen plant andtree material that has yet to be fully decomposedor broken down into soil. The litter layer of theforest floor begins where fallen material meetsthe air. Items in this layer are easily recognizableand have not begun to decompose. Just belowthe litter layer is the duff layer. In this layer isthe litter that is partially decomposed. It ends atthe first soil layer. The first soil layer is muchmore compacted than the loose forest floor andcontains some mineral particles. The visualappearance of this layer is much like salt andpepper. The “salt” is the sand (mineral) particles,while the “pepper” is the organic part of the soil.


When trees lose their leaves, needles, or fruits,or when a tree itself dies and falls to the ground,small soil organisms (henceforth known ascritters) begin breaking those complex structuresdown into more simple ones. It is not easy forcritters to break down these complex carbonstructures. Wood, nuts, and cones are generallymore complex than leaves. It makes sense whenyou think about what you see on a forest floor.You can identify the same downed tree year afteryear, but thousands of leaves shed in the fallseem to disappear each year. The more complexa structure, the longer it will remain on the forestfloor before being fully decomposed.

So we know what the forest floor is, but how can we use the forest floor as an indicator of how quickly nutrients are cycled through aforest? The plant material that falls from a tree is decomposed by the critters in the soil. Thisstep is very important because plants cannot use nutrients directly from the fallen material ofother plants. The critters break these compoundsdown and make the nutrients re-available to plants. The faster the critters break thecompounds down, the faster they will be re-available to plants.

The rate of nutrient cycling can be comparedbetween two forest types based on the depth of the forest floor. A deep, homogeneous (made up mostly of the same thing) forest floorindicates slower decomposition, smaller critterpopulations, and slower nutrient cycling. Ashallow, diverse forest floor indicates fasterdecomposition rates, larger critter populations,and faster nutrient cycling.

PINE PLANTATION VS. MIXED FORESTIn Wisconsin, most of the plantation forests are red or white pine. Of the 46 percent of thestate covered in forests, 4.5 percent of that isplantations. In general, a plantation forest willhave lower levels of species diversity than amixed forest. The richness will be low becauseusually one species of tree is planted. Theevenness will be high if there is only one treespecies. The structural diversity in a plantationwill also be lower than in a mixed forest. All the trees are usually the same age and similarheight. There might be forbs growing in areaswhere sunlight reaches the ground, but there are not likely to be other understory layers. Thefunctional diversity in a plantation is generallylower than that in a mixed forest because thereare fewer organisms to cycle nutrients, providehabitat and food, and photosynthesize.

Having lower levels of diversity than mixedforests does not mean plantations have lessvalue. Plantations produce more wood in asmaller area than mixed forests because thetrees have less competition in a plantation and can grow bigger faster. Management and harvesting are also easier in a plantationbecause there are fewer variables (such asunderstory plants) to account for. Ecologically,pine plantations may have fewer insects, whichis great if you are looking for a nice open area to camp and hike in. Some wildlife, such aspredatory birds that need open areas to hunt,may prefer plantations. Plantations also add tothe overall diversity of the landscape.


SUMMARYWe have discussed three different types of forestdiversity, but what does it all mean? It is generallythought that more diverse systems are morestable against disturbances. They also host agreater variety of plants and animals. Manypeople believe that a more diverse ecosystem is a better one, but better how? More beautiful?More wildlife? More natural? It is important thatinstead of categorizing all ecosystems as goodor bad, it is wiser to determine the value indiversity of each ecosystem individually. Thediversity measures that we have discussed are all indicators of ecosystem health. Theseindicators are specific to each type of forest.Different forest types have different levels of biological diversity. Healthy systems areexpected to maintain the levels of diversityexpected for that particular type of system. Forexample, in Wisconsin, jack pine barrens andoak savannahs are naturally occurring, resilientecosystems that have very low diversity. Theyprovide habitat for a variety of animals such as the sharp-tailed grouse. Yet, they have aneven-age structure, one species composition,and slower nutrient cycling. It is important in this lesson that students understand that someecosystems only have the ability to achieve acertain level of diversity.

PROCEDUREINTRODUCTION1. Begin by introducing the concept of the day –

forest diversity. Ask someone to define whatdiversity means. (Different, variety.) Explainthat studying diversity in a forest meanslooking at how many different parts a foresthas. These parts can be the tree species,structural layers, animals, or forest processes.

2. Tell the students that you are going to usethem to demonstrate some principles ofdiversity. Tell them that together they make up the class, just like trees make up a forest.Ask them to form groups based on eye color.Each group must have the same eye color.After they form these groups tell them thatthey have just separated the class into groups of students because of one of theircharacteristics, just as trees are separatedinto different tree species by their individualcharacteristics. The different groups representthe composition of the class based on eye color.

The diversity of their composition can bedetermined with two measurements: richnessand evenness. Tell the students that richnessis the number of different groups of thingsthere are. What is their richness? (It will behowever many eye color groups the classhas.) Evenness is measured by looking at thenumber of people or things in each group andhow the groups are distributed. For example,two groups of three and one group of 12would not make an even distribution. A groupof five, a group of six, and a group of sevenwould represent evenness. Remember that“even” does not mean exactly equal. It meanspretty equal. The more rich and more eventhe composition, the more diverse it is. Is yourclass diverse?

Tell the students that the richness andevenness of the forest composition measuresthe tree species diversity of the forest.Measuring the species diversity in the forest is only one way of measuring diversity. Theywill be collecting data on species, structural,and functional diversity. With their results, they will compare the diversity of two differenttypes of forests.


ACTIVITYDivide the class into eight groups. Hand out aclipboard and Student Pages 1A-B, ForestDiversity Data Sheets to each group. Explain thateach group will work separately to complete theworksheets. Each group will also be assigned towork in a different plot.

Part A1. Tell students that the first type of diversity

they will be studying is species diversity. Have students look at the top of Student Page 1A, Forest Diversity Data Sheet 1A –Species Diversity.

• Tell students that first they will be looking atrichness and evenness to determine speciesdiversity. It is very similar to what they justdid by dividing the class by eye color. Firstthey locate all the trees that are bigger thanfour inches in diameter and determine thespecies. (Four inches is used as a minimumdiameter to conserve time. It eliminates theseedlings and reduces the number of treesstudents have to count. If your forest onlycontains young trees, you may want to lowerthe minimum diameter to ensure there areenough trees for students to count.) Explainthat if they fold a piece of paper in half thelong way it is approximately four incheswide. They can use this as a reference tomeasure diameter. Each group should havea tree identification book or dichotomouskey to identify the tree species.

• Once students collect their data, they shouldadd the totals for each species and the totalfor all the species combined. Then, theyshould decide the richness and evenness of their forest area. Richness is measuredon a scale of 1 to 5 based on the number of species in the plot, and evenness ismeasured by comparing the number of

trees there are of each species. “Even”composition is about equal numbers ofindividuals of each species. What if there isonly one species? We would consider thiseven, since there is nothing for it to beuneven with.

2. Have students come back together as onelarge group. Compare results from differentgroups. Was the species richness the samefrom group to group? Was the evenness thesame from group to group? Discuss that even though there might have been minordifferences from plot to plot, overall the forestis probably fairly consistent.

• Tell students that they will now have theopportunity to examine data from anotherforest that is different from the one theysampled. If you will not be gathering datafrom a second type of forest (see Part D,page 220), hand out either Student Pages

2A-B, Forest Diversity Data Sheet – PinePlantation OR Student Pages 3A-B,Forest Diversity Data Sheet – Mixed Forest.If you are gathering data from another typeof forest, save this discussion until after datahas been collected.

• Have students read the description of theforest so they can visualize what it looks likeand then compare their data on speciesdiversity to the data given.

• Ask students which of the two forests hadmore richness. (Mixed.) Ask students whichof the two forests was more even. (PinePlantation.) Tell them that is likely becausethere is only one species of tree in theplantation, so there is nothing to be unevenwith. Ask students which forest has morespecies diversity. (Likely they will saythe mixed.)


Part B1. The next type of diversity that students will

study is structural diversity. Direct students to the bottom of Student Page 1A, ForestDiversity Data Sheet 1A – Species Diversity.

• Discuss with students what the structure of a forest is. (The horizontal and verticaldistribution of layers in a forest, includingheight and species present.) Review thelayers:Litter/Duff Layer: Litter is the surface layerof the forest floor composed of leaves,twigs, needles, etc. The duff layer is thepartially decomposed layer of the forest floorjust below the litter.Overstory: The uppermost trees in the forest.Understory: The vegetation below theoverstory, including trees, shrubs, and forbs.Trees are differentiated from shrubs byhaving one stem. Shrubs have multiplewoody stems. Forbs are non-woody plants.

• Point out some different forest layers to thestudents. Be sure that they understand thata layer consists of a fairly continuous massof things. Think about a peanut butter andjelly sandwich. It has a layer of bread, alayer of jelly, a layer of peanut butter, and a layer of bread. If there were only a fewdrops of jelly between the peanut butter andthe bread, would it really be a “layer”of jelly?No, we’d probably call it a peanut butter anddrop of jelly sandwich. The same thing istrue with forest layers. Just because thereare a few plants in the first two feet of theforest, it does not mean there is a forb layer.In the same token, if there is just a hole inthe jelly, we would still call it a layer.

• Tell students that next they will be studyingthe structural diversity of a forest. On thebottom half of Forest Diversity Data Sheet 1A, they need to circle “Yes” or “No” for thepresence of each layer. The litter layer willbe studied separately, so it is not present in this portion of the Data Sheet. Next, tellstudents that they have to list any wildlife, signs of wildlife, areas of habitat, and foodsources they see in each layer. Remindthem that if they do not have a layer, theymay still have signs of wildlife at that level of the forest. For example, a spiderwebfound on the base of a tree in the overstorywould be listed at the forb layer. You canalso introduce your students to the termscat, a scientific term for animal feces.

2. Once students have gathered their data, havethem come together as a large group. Go overthe results of the Data Sheet. Were the samelayers present in all the plots? What types of wildlife, signs of wildlife, habitat, or foodsources did they find? Were these consistentfrom plot to plot?

• Explain that the first data set they collectedwas on vertical structure. This tells howmany layers there are in the forest. Askstudents if they think more layers meanthere is more diversity. (Yes, but it is notalways that simple. Some animals needopen layers to hunt or nest in. If there arenot openings in the forest, these animalsmight not be found there. For example,many predatory birds use the open areaunder the forest overstory to spot and catchtheir prey.)


• The second data set they collected was tohelp them assess horizontal structure of aforest. This is a measure of the diversity oflayers across the landscape. Ask studentswhat they think would happen to the wildlifethey identified in their forest if one of theforest layers disappeared. (Some of themmight lose their food or habitat and need torelocate to survive.) Ask if all animals usethe same forest layers. (No.) Ask what theimplication of this is for different kinds offorests with different layers. (Different forestswith different layers support different kindsof wildlife. It is necessary to have a varietyof ecosystems and forests.) Explain that partof structural diversity is looking at a widerarea than just within one forest area like the one where their plots are located. It isimportant to study the forest layers of manyadjoining forests and ecosystems.

• If you will not be gathering data from asecond type of forest, have students look at the structural diversity section of StudentPages 2A-B, Forest Diversity Data Sheet –Pine Plantation or Student Pages 3A-B,Forest Diversity Data Sheet – Mixed Forest.If you are gathering data from another typeof forest, save this discussion until after datahave been collected.

• Have students compare their data onspecies diversity to the data given.

• Ask students which forest has more layers.(Mixed.) Ask students which forest has moresigns of wildlife. (Likely the mixed.)

Part C1. Next have students look at Student Page

1B, Forest Diversity Data Sheet –Functional Diversity. Explain that this is the third and final type of diversity they will be studying.

• Ask the students if they know what a functionis. Try to get them to figure it out by usingthe word in context. Ask them what a functionof a school is. They will probably say toteach us things. Keep them brainstorming.There are many functions of school. (Makingnew friends, playing games, sports, keepingyou out of trouble, lets whoever takes careof you do other things during the day, feedsyou hot lunch, etc.) Prompt them withquestions such as what function doesschool have for your teachers, janitors, and cooks? (Jobs.) Let them brainstorm for a while. Forests are a lot like schools.They both have many functions. Have thestudents brainstorm some functions of aforest. (They provide homes for plants andanimals, release oxygen and use carbondioxide, cycle nutrients, retain water, etc.)Tell students that the last type of diversitythey are going to study is functional diversity.

• Show the class where the forest floor beginsand where it ends. It starts at the very top of the litter and continues down to the top of the soil. The material that is partiallydecomposed is called duff. Show studentshow to measure the depth by pushing the ruler through the litter and duff until ittouches the soil. Remember, the first soillayer has minerals, like sand, in it. They may have to estimate the depth if the depthwithin their sample square is uneven. NOTE:If this activity is done in a deciduous forestafter leaves have fallen in the fall, havestudents remove the freshly fallen leaves from the litter layer before takingmeasurements. A pile of freshly fallen leaves will misrepresent the amount ofdecomposition that is actually occurring in the forest.


Show students the Forest Floor SamplingSquare. Tell them to stand at one corner of their plot and toss the square inside theplot. Remind them that this is a Forest FloorSampling Square; it does not work well if it is tossed onto a tree or shrub, especially if they cannot retrieve it. Therefore, theyshould throw it like a frisbee and keep it low to the ground. Each member should take aturn gently tossing it into the plot startingfrom a different corner. Wherever the squarefalls is where they will take their measurement.They need to do this four times, once fromeach corner.

• The next data they need to collect onStudent Page 1B, Forest Diversity DataSheet is the composition of what is insidetheir sample. Show the students some of thedifferent things they could find in the layer –pine needles, deciduous leaves, pine cones,acorns, whatever happens to be on theground around you. They then need todetermine the evenness of the composition.Does each type of material cover the same amount of surface area? (If yes, the composition is even.) NOTE: Whenmeasuring evenness students shouldcompare the overall surface area taken up by an item, not the number of each item. They also need to determine thedecomposition level. Point out the definitionsat the bottom of Forest Diversity Data Sheet1B and explain them. Explain that they needto select the level of decomposition presentand mark it on their sheet.

• Remind students to only disturb the forestfloor inside of the sampler. When they arefinished, they must put all the material backinside the sample box and make it look as ifit had never been touched.

2. Ask the class to look around and above themat all the trees and shrubs. If they all loseneedles, leaves, twigs, etc., why isn’t theremore stuff on the forest floor? (It is beingdecomposed and returned to the soil.) Askwhat would happen without decomposition?(The material on the forest floor wouldcontinue to build up endlessly.) Ask if theyknow what a nutrient cycle is. Use a NutrientCycling Poster to demonstrate the nutrientcycle, if you have one. Basically, critters(decomposers) break down the material that falls to the forest floor and it returns to the soil. Trees and other plants use thesenutrients to survive. Without the continuouscycle, the trees would not get the nutrientsthey need to live.

• If you will not be gathering data from asecond type of forest, have students look atthe structural diversity section of StudentPages 2A-B, Forest Diversity Data Sheet –Pine Plantation or Student Pages 3A-B,Forest Diversity Data Sheet – Mixed Forest.If you are gathering data from another typeof forest, save this discussion until after datahave been collected.

• Have students compare their data onspecies diversity to the data given.

• Ask students which forest has the deeperforest floor. (Likely the Pine Plantation.)Have students compare the compositionof each forest floor. Ask which has thehigher level of decomposition. (Mixed.)The nutrient cycle is one part of functionaldiversity in the forest. Based on the data,have students assess the overall functionaldiversity of each forest. A thick forest floorusually indicates slower decomposition andtherefore slower nutrient cycling. This canbe an indicator of low functional diversity.


Part DIf you have the option of visiting another type offorest, give students another set of Data Sheetsand have them collect data. Lead a discussionusing the questions in each section above tocompare and contrast the two types of forestsand the level of diversity found in each.

CONCLUSION1. Review the differences in diversity between

the two forests with students. (The pineplantation had lower species richness than the mixed forest but higher evenness. Thepine plantation had fewer structural layersand, therefore, less structural diversity thanthe mixed forest. The pine plantation alsolikely showed fewer signs of wildlife than themixed forest. The pine plantation had a thickerforest floor than the mixed forest, indicatingslower nutrient cycling and therefore lowerfunctional diversity.) To pull it all together, askstudents if they would like to have more mixedforests or more pine plantations. Why? (Likelythey will say mixed forests because of thehigher levels of diversity, animals, etc.)

2. Discuss the implications of having all mixedforests. Have students think of the role ofplantations in the overall landscape (horizontalstructural diversity). Ask which is morediverse, a state with all pine plantations or all mixed forests, or a state with bothplantations and mixed forests. (A state withboth plantations and mixed forests.) Askstudents what benefits pine plantations mighthave over mixed forests. (They produce morewood in a smaller area than mixed forestsbecause the trees have less competition in a plantation and can grow bigger faster.Management and harvesting are also easier in a plantation because there are fewervariables [like understory plants] to accountfor. Ecologically, pine plantations may havefewer insects, which is great if you are lookingfor a nice open area to camp and hike in.

Some wildlife, like predatory birds that needopen areas to hunt, may prefer plantations.)Explain that, because we use so manyproducts that come from the forest, we need a lot of trees. If we did not have plantations tocut, we would have to cut more mixed forests.

3. Ask the class if they think that a more diverseecosystem is a better ecosystem. Tell theclass that many ecosystems exist naturallythat would have a very low diversity in all ofthe measurements that we have taken. Askthe students if they have seen a pine barren,oak savanna, or if they have been to a forestin Canada or Alaska. Tell the students thatthese forests naturally often have only onespecies of tree. Many times all of the trees arethe same age and height. Are these forestsunhealthy or bad? No, they are just that way.They are best suited for that environment.

4. Ask the students if they can name sometypes of forests found in Wisconsin. (Pine,aspen/birch, spruce/fir, maple/basswood,oak/hickory, urban.) Tell the class that eachtype of forest has its own diversity level. Anoak savanna with a scattering of oak trees inan open prairie would have a very differentdiversity than a coniferous forest full of pinetrees. But the oak savannahs of Wisconsinshould all have diversity measurementssimilar to each other’s. If we knew thediversity level of a certain type of forest, wecould compare the diversity levels of individualforest samples to that accepted value. Ahealthy forest has the proper diversity level for its own forest type. Would a pine plantationbe healthy if it had many layers, differentspecies, and a high decomposition level?Probably not. The same goes for the mixedforest. If it showed an extremely low diversitylevel like a plantation, we could hypothesizethat it was unhealthy.



5. Ask what the importance of forest diversity is. Why not have all one type of forest likepine plantations or mixed forests? Have thestudents brainstorm for a while. Remind themof the benefits of diverse forest and a varietyof different types of forests. Many of the foodsthat we eat, the medicines we use, and thematerials that we use for clothing, shelter, andother products came from the forest. Peoplehave discovered a wide variety of uses for ourforests and many people believe that thereare even more uses to be found. Plants andtrees that we have not yet discovered maybecome important in the future for medicine,food, or materials. If we lose forest diversity,we will lose all of these possibilities before weever have a chance to explore them.

SUMMATIVE ASSESSMENTHave students do a diversity study of shoppingcenters or car lots in their town. Have them lookat the stores/cars present in different locations.What is the richness? What is the evenness?How are they distributed across the landscape(town)? What is the level of functional diversity?This could be studied by measuring hours thebusinesses are open, parking availability, orrelative numbers of salespeople. Have studentsbe creative in coming up with questions to askabout the businesses to measure their level of diversity.

REFERENCESFinan, A. S. (Ed). (2000). Wisconsin’s Forests atthe Millennium: an Assessment. Madison, WI:Wisconsin Department of Natural Resources.PUB-FR-161 2000

Helms, J. A. (1998). The Dictionary of Forestry.The Society of American Foresters.

Strathe, S., Hylla, N., Kiser, S., Boyd, E., &Dreier, P. (2000). Wisconsin Forestree – Bridgingthe Gap Between Environment and Economy.Central Wisconsin Environmental Station.

Wisconsin’s Biodiversity as a ManagementIssue. (1995). Madison, WI: WisconsinDepartment of Natural Resources.

Young, R. A., & Giese, R. L. (1990). Introductionto Forest Science. New York: John Wiley & Sons.

Tree Species Number of Trees MoreThan 4" in Diameter

Structural Layer List wildlife, signs of wildlife, habitat,food sources.

Is the layerpresent?

FOREST DIVERSITYDATA SHEET A


1A

Which plot are you studying?___________________________________________________

SPECIES DIVERSITY

Total Number of Trees________________

Richness: A measure of the number oftree species in an area.

More Tree Species = Greater Richness

How many species of trees?

1 2 3 4 5

Evenness: A comparison of the numberof trees of each species.

Equal Numbers of Each Species =Greater Evenness

Even | | | | | | | Uneven

STRUCTURAL DIVERSITY

1. Overstory Yes No

Yes No

Yes No

Yes No

2. Understory

A. Trees

B. Shrubs

C. Forbs

Sample


1BFOREST DIVERSITY

DATA SHEET BWhich plot are you studying?___________________________________________________

Depth (cm) Composition (Leaves, Twigs,Seeds, Pine Cones, Etc.)

Level ofDecomposition

Evenness ofDecomposition

FUNCTIONAL DIVERSITY

1

2

3

4

Even

Uneven

LowMedium

High

LowMedium

High

LowMedium

High

LowMedium

High

Even

Uneven

Even

Uneven

Even

Uneven

LOW DECOMPOSITION: You can tell what most, or all, of the materials are made of.

MEDIUM DECOMPOSITION: You can tell what some of the materials are made of.

HIGH DECOMPOSITION: You cannot tell what most of the materials are made of.

Compare the amounts of material in each category. If there is more material of highdecomposition than low decomposition, the overall level of decomposition is high. If thereare about equal amounts of decomposed materials and non-decomposed materials, thelevel is medium.

FOREST DIVERSITY DATASHEET – PINE PLANTATION A


2A

SITE DESCRIPTION

Envision tall red pine trees towering 30 feet above your head. You can hear the windrushing through the needles in the tops of the trees swaying above you. All around you are straight tree trunks that are nearly all the same size. A chickadee sits on a shortbranch sticking out of one of the trees. You notice that there aren’t many branches aroundyou; most of them are high up in the trees. On the forest floor is a thick, soft layer of pineneedles with cones and twigs scattered around. In patches of scattered sunlight, there area few small pines growing. You are in a 25- to 35-year-old pine plantation.


2BFOREST DIVERSITY DATA

SHEET – PINE PLANTATION B


3AFOREST DIVERSITY DATA

SHEET – MIXED FOREST A

SITE DESCRIPTION

All around you are plants of various heights. It is hard to see all the tree trunks clearlythrough the green leaves around you. High above your head are white pine and redmaple trees. One of the maples is dead and still standing, providing a nesting area forwildlife. In one corner is a big, old hemlock tree. A breeze rustles the leaves of shrubsaround you. They are about your height, and on some of them are sharp thorns. A fewpine seedlings are growing on the forest floor among wild strawberries and other forbs.There are twigs, leaves, maple seeds, and pine cones on the ground around your feet.


3BFOREST DIVERSITY DATASHEET – MIXED FOREST B

Documents

U78 FE3 Quark - uwsp.edu · LEAF Guide • 7-8 UNIT Field Enhancement 3: Forest Diversity 211 MATERIALS LIST FOR EACH GROUP (8 TOTAL) • Copy of Student Pages 1A-B, Forest