NRES 250 Exam 2

Why sample forests?

General info, management, timber valuation, other valuation

What are common tree measures? (6 total)

Diameter, Basal Area, Height, Age, Volume or Weight, Trees per Acre

How high is DBH? (Diameter at breast height)

4.5 ft (or 137 cm)

What are used to measure bole diameters?

DBH tape, calipers (most accurate), Biltmore stick (not as accurate as other two but is fast)

When measuring DBH, what should you watch out for?

Leaning trees (make sure measuring at the same angle the tree is leaning), deformities (don’t include defect in measurement), slopes (measure at the top of the slope)

Seedling vs. Sapling

Seedling = less than 4.5’ tall (1-5 yrs old)

Sapling = DBH is between 0 and 5.5 inches (5-15 yrs old)

What is pole or pulpwood?

paper products

What’s the DBH of pole or pulpwood? Why don’t they have to be as large as sawtimber?

Hardwood: between 5.6 and 11.5 inches

Softwood: between 5.6 and 9.5 inches

Trees with this diameter are used for paper products and get shredded so they don’t need to be as thick

Typically 15-60 yrs old

What is the DBH of sawtimber or sawn products?

Hardwood: 11.6 inches or greater

Softwood: 9.6 inches or greater

typically 60 yrs or older

What is a cull? What are the issues with culls?

a non-merchantable living tree. They use resources that other, merchantable trees could be using. But be aware of wildlife potentially using the tree and its other uses in the environment before just cutting it down

What is a snag?

A standing dead tree; isn’t using any resources of other trees except for maybe shading other trees. Also be aware of it’s other uses in the environment (like for wildlife) before just cutting it down.

What is basal area?

shows the density of trees (the smaller the trees, the bigger the basal area)

the outside bark cross-sectional area measured at DBH; is expressed as ft² per acre

BA = D² * 0.005454 (Ex. a 13.6 inch tree is about equal to 1 ft²)

What are the types of tree heights? (3 total)

Total height: from the top of the crown to the bottom of the bole

Merchantable height: from the ground to minimum top diameter (where the bole becomes too small or too branched to be marketable timber; in pulpwood: 3”, in sawtimber: 8 or 10”)

Live crown height: how high the bole of the tree goes until it meets the crown

What are the methods for measuring total height? (3 total)

clinometer (top height minus negative bottom height when standing 66’ away), vertex hypsometer, estimate with a trained eye

Sawlog vs pulpstick and what tool is used to measure them?

Sawlog: 16 ft long, can count in half logs after the first full log

Pulpstick: 8 ft long, can only measure in whole sticks

Merritt Hypsometer is used (start at 25” away)

How is the age of a tree measured?

Wither with an increment borer and counting the rings or the branch whorls

What are the sampling methods for trees? (two total)

Fixed radius plot sampling

variable radius plot sampling (aka point samping or prism sampling)

Describe fixed radius plot sampling

Measure circular plots that are a fraction of an acre; if the tree is on the plot, measure it (the smaller the tree, the smaller the plot; 7-13 trees at least for a representative sample)

Seedlings = 1/1000th acre

Saplings = 1/500th acre

Pulpwood = 1/10th acre

Sawtimber = 1/5th acre

Describe variable radius plot sampling (aka point or prism sampling)

Use a prism to determine which trees to measure (walk in a circle around the tree) if the trees are “in,” or whose bole remains within its original bole when shifted by the prism, measure them, if not, don’t. The 10 factor prism is the most common so if 12 trees were in, multiply by 10 and you’ll know that there’s 120ft²/acre of basal area

How to sample trees for management?

Measuring density using either trees per acre or basal area per acre. These measures are obtained by measuring all trees or sampling using fixed or variable radius plots

How to sample for timber valuation?

volume per acre

Sawtimber: board feet per acre

pulpwood: cords per acre

Sampling using either method

What are board feet?

The most common way to measure sawtimber volume

1 board foot = plant that’s 1”×12”×12” and is expressed by board feet per acre

What is a cord?

The most common way to measure pulpwood volume

1 cord = 128 ft³ of stacked pulpwood or 4’x4’x8’ and includes all wood content, bark, and open gap space

What was agriculture like prior to 1960s?

small, diversified farms that were mostly family owned. Rotation farming was common

How did farming practices prior to the 1960s affect wildlife?

Wildlife thrived because there was diversity of crops. Ex. grain created an understory with food and cover, hay was similar to native grasses and provided perm. cover and nesting. There was also lots of corridors and food access

What was agriculture like after the 1960s?

Larger farm equipment and fields, less rotation, less diversity, increased pesticide use rather than natural fertilization from rotating crops, less family-owned farms and more corporate farms with focus on revenue and food off the land, not its value. Farm operations tripled and increased by 70%.

How did agriculture practices after the 1960s affect wildlife mgmt?

Difficult to manage on private lands because can’t get much access. Trends of species are known but causes of trends are certain and some species aren’t studied (ex. herps)

What was the purpose of the Farm Bill?

established in the 1930s b/c of dust bowl to incentive farmers to set aside land to prevent erosion and soil into water ways. Also incentives to restore native vegetation (corridors, nesting habitat, buffer zones)

What are the goals of the Farm Conservation Program?

• Erosion control

• Water Protection

• Wildlife Habitat/Restoration

• Aid farmers – natural disaster

What is the farm conservation program under?

Farm service agency that’s part of USDA

What does payment depend on for the Farm Conservation Program?

• Length of retirement (10 years)

• Size of the area

• Vegetation created

• Region

What is the Conservation Reserve Program?

Voluntary participation, 10-15 yr long contracts, can renew contract or revert to crops at the end, to be eligible, the land must be cropland that was planted 4/6 past years and suitable as riparian buffer. (Enrollment has been declining recently)

What are the ways to manage landscapes?

Patches

Corridors

Hedgerows and fencerows

Define patches and how to manage them

areas of restored or native vegetation (ex. Woodlots, wetlands, prairie remnants); typically small and isolated

provide cover for wildlife

improvements: larger, connect them, more numerous and close together, include native plants, structurally diverse

Define corridors and how to manage them

linear strips of vegetation that connect habitat patches, slow movement of soil and water, movement, and genetic flow

improvements: continuous, wider, more than one corridor connecting patches, native plants, structurally diverse

Define hedgerows and fencerows and their growth

Dividers between fields with or without fences; planted or natural; birds drop seeds in fences and trees result; protect from wind, erosion

What is a rangeland?

plant community dominated by grasses, forbs, and shrubs

What is the primary use of rangelands?

grazing for cattle and livestock

What factors determine the location of grasslands?

moisture availablility (precipitation)

distrubance frequency

What are examples of disturbances to rangelands?

fires, invasive species, urban development, oil and gas rigs, domestic species, disease, grazing (native vs domesticated), etc.

What did historic rangeland management look like?

Main use = grazing for livestock, so predators that hunted livestock were targeted and killed. Management also focused on increasing game species that lived on rangelands (ex. mule deer, sheep, elk, etc.)

Modern management of rangelands?

mainly fire management with more of a focus on the entire ecosystem and increasing biodiversity and native species (plants + animals)

What is succession in rangelands?

grass + forbs —> shrubs and woody

This progression is natural but was set back by natural fire disturbance and other disturbances (modernly, this hasn’t been happening)

Native vs domestic grazers on rangelands

Native = lighter, more selective w/ what to eat (don’t eat everything and down to the dirt)

Domestic = heavier + larger which leads to more trampling of the land and they eat everything

advantages of fire for rangeland mgmt?

• releases nutrients back into the soil

• cheap (per acre)

• provides new area for growth

• opens sunlight to reach deeper

• reduces intensity of natural fires (uses up fuel to burn)

• fire-dependent species can thrive

• may reduce non-fire-tolerant invasive species

• when new growth begins, it’s more nutricious and higher quality

Disadvantages of fire mgmt for rangelands?

• always potential for it to go out of control

• weather dependent

• can affect nests or young

• public opinion is usually against it

• risks to people (buildings burned down, smoke inhalation, etc.)

• restricted on where the fire can happen (ex. must be open areas)

Benefits of grazing for rangelands

increase species richness

sets back succession

Types of grazing systems for rangelands

continuous grazing

rotation grazing (3 types: deferred, rest, and open gate)

Describe continuous grazing

no restrictions, livestock remain in same pasture for undetermined period of time; the most common type in US, low cost and labor intensity, but increases less desirable and poor forage quality plan species, invasive species, and soil erosion

Describe deferred rotation grazing

happens during important growing periods to allow plants to set seed without being grazed; live stock are regularly moved to new paddocks

Describe rest rotation grazing

pastures are no grazed for 1 or more years. In the early season, cattle are all on one paddock, then moved to a new one during the mid season and again for the late season

describe open gate grazing

One paddock is open in the early season and grazed intensively and kept short the rest of the season, then in the mid season a gate is opened into a second paddock while keeping access open to the first paddock, then in the late season and third gate is opened and livestock have access to a total of three paddocks

What are the benefits to rotational grazing on rangelands?

improve vegetation, reduce the need for irrigation, reduce erosion, limits the long-term damage to pastures, are financially productive over time

What are the disadvantages to rotational grazing?

labor intensive, moving livestock between pastures takes a lot of work and time and must be managed, requires a lot of gates

Why are fences a problem for wildlife on rangelands?

They inhibit the native animal’s natural range and stop them from traveling where they would naturally travel

Methods to improve fences for wildlife on rangelands?

electric fences: prevent mortalities of wildlife, but don’t allow for their movement still

modifications that are species specific and based on their needs

Define forest ecology

the scientific study of the forest ecosystem’s interrelated patters and processes of all organisms

What is forest ecology important?

forest mgmt is applied forest ecology; there are predicable patterns within forestry that if they are known, decisions and management should be based on that

How do trees regenerate?

seeds (wind, mechanical, animal)

sprouts (root and stump - coppice)

rhizomes and stolons

fragments and layering (like cottonwoods that when cut down, will sprout)

Why is density important?

to maximize lumber production of an area, disease, wildlife manipulation + competition

What leads to succession and what are the types of succession?

competition within a species doesn’t change composition while competition between species does

Leads to succession (replacement of vegetation and other organisms, primarily based on shade tolerance, leads to climax vegetation)

disturbance also causes succession

Primary: bare rock (volcanic eruptions) or severely disturbed soil (retreating glaciers and sand dunes)

secondary: vegetative community that experiences disturbance (ex. from a fire; early successional plants come back first and set the foundation for the rest)

What is a sere?

distinguishable stages of serel community “barreling” towards the climax

“the complete sequence of all transitional plant and animal communities that replace one another in an ecosystem over time during the process of sucession”

types: xearch (bear rock), hydrarch (on or near water like a pond or lake), mesarch (substrate other than rock or water like mudflow or glacial moraine)

What are types of disturbances in forests?

fire, wind, ice storms, moisture stress, insects and disease, wildlife, humans

Importance of disturbances in forestry?

leads to succession (don’t want a monotypic stand with no competition) and biodiversity, shad-tolerant trees fill gap after shade intolerant grow. the overstory tells the story about where in succession a stand is

Define population dynamics

how populations change

ex. abundance (N) or biomass (B)

What are dynamic rates and what do we look at and what are factors that affect?

The shape of the population “structure”

natality (terrestrial organisms), recruitment (fisheries), growth, mortality

factors: species life history, ecosystem resources, anthropogenic (harvest, stocking, habitat alterations), competition, density (#/area)

Define density-dependent factors

Density matters; typically biotic factors like competition (food, space) or diseases

the number of individuals matters for how much each factor influences pop.

Define density-independent factors

number of individuals isn’t not important, the factors will influence individuals similarly whether there is 5 or 500. typically abiotic factors ex. temp, oxygen, precipitation, pollution

What is natality?

used in wildlife

lower fecundity = fewer births

more parental care = higher survival

larger offspring = higher survival (also easier for humans to monitor)

What is recruitment

used in fisheries

high fecundity = more births

less parental care = lower survival

smaller offspring = lower survival (also harder for humans to monitor

highly variable especailly for broadcast spawners (no parental care, eggs and young and vulnerable to abiotic and biotic factors that vary annually)

What does density-independent look like for recruitment?

no relationship (slope) between number of adults and number of young either because of a carrying capacity, the same number of recruits as stock, highly variable recruits, or a constant positive relationship (ex. 4 recruits per adult - the resources are not limiting)

What does density-dependent look like for recruitment?

constant negative slope (more adults leads to few recruits; resources are limiting) or slope depends of stock (ex. low density = higher rate and high density = lower rate, where at first resources are not limiting then do become limiting once a cap is reached)

What does growth look like for individuals?

increase in length or weight, current size (if already grown, won’t grow more or will in very small amounts), genetics (how big individuals of that species usually grow), environmental conditions (density-independent growth like temp), resources (density-dependent growth like habitat or food; low density = more resources = faster growth)

What is determinate growth?

in warm-blooded organisms (birds and mammals), there’s stable growth and reach a point where they stop growing, resource-dependent growth, not as much temp. dependent

What is indeterminate growth?

in cold-blooded organisms like fish, is variable growth where growth starts fast then slows as the fish matures, but never stops; resources and temp. can impact

How to determine growth of organisms?

mark-recapture (look at the growth rate over time) or find the mean size of the organisms at a certain age group and maybe look at models

What is mortality/survival and what impacts it? (Hint: there are three types)

how many organisms die/survive a period (can look at pop. percentage)

Type I - mammals: high survival then reach an age with quick drop-off

Type II - birds: number alive declines throughout age class relatively consistently (linear, negative slope)

Type III - Fishes: many die in early age classes but if they make it past then, can survive for awhile and it’s steady

max size of organisms, when it reaches maturity, how it reproduces,

density-independent factors: harsh winter, drought, flood, fire, etc.

density-dependent factors: competition, starvation, cannibalism)

How to estimate mortality/estimation of fisheries + wildlife?

observations (rare)

decline in abundance

age sampling

mark-recapture

telemetry

types of mortality in fisheries and wildlife?

harvest (hunting and fishing)

natural (any non-harvest mortality, including predation, starvation, and environmental (even something like a chemical spill))

Describe exponential growth of fisheries and wildlife pop.

Initially slow growth b/c few adults then rapid growth

density-independent growth, there’s plenty of resources

Describe logistic growth of fisheries and wildlife pop.

initially exponential then growth slows and stops b/c density-dependent factors (limited resources and carrying capacity (k))

What data do you collect on sampled individuals in fisheries and wildlife?

species, abundance, size (both length and weight), mark/tag present, health, sex, age

Why is it important to determine age when sampling individuals in fish/wldf?

learn ab recruitment (young fish, multiple age classes), learn ab survival/mortality, maturity and age of reproduction, growth rates at certain ages, cohorts (individuals born in the same year), age classes

How to determine age in fish/wldf?

true/known age found by organism being born in captivity or being tagged when age-0. More commonly is estimated w/ various methods w/ tradeoffs (subjectivity, errors, sacrifice/harvest potentially, sometimes coarse estimations such as immature vs mature)

Calcified structures of fish?

circuli grow closer when growth slows (annulie is a tight group of circuli once per year, so older individuals are harder to age)

scales, spines, otoliths, cleithra

scales = easy and nonlethal but leads to underestimation and poor estimation of older individuals (more accurate for young individuals)

otoliths = much more accurate but requires sacrifice, more time, and more resources

Calcified structures of mammals?

teeth (if they’re present, can section and count or look at wear), antler/horn growth rings

can also be categorized as born that year (YOY), Hatching year (HY), after HY (AHY), mature vs immature, and size, coloration, or behaviors

Why is knowing sex important in wldf and fisheries?

Know growth, maturity, and lifespan of individual (ex. in fish, females are typically larger, mature later, and live longer); hunters and anglers will have preferences; females are more important at low densities; and some regulations are on basis of sex (Ex. can only get 2 bucks/season or only shoot male turkeys in the spring)

How to determine sex of fish/wildlife?

sexual dimorphism (diff sex has diff features ex. sexual dichromatism which is diff sexes have diff coloration)

look at gametes or reproductive organs, can ultrasound in some cases

Describe a chromosome’s structure

DNA built from nucleotides, a sequence of nucleotides is a gene, a loci is a location on a gene, alleles are alternate gene at a loci and can be dominant or resessive.

Genotype vs phenotype

genotype: inherited instructions within genetic code

phenotype: observable characteristics or traits, including morphology, physiological properties or behaviors

Why are genetics important for mgmt in wldf and fisheries?

Know the health of pop. (ex. genetic diversity = resiliency + adaptability to changing conditions or disease outbreaks)

help propagation (when humans pair up males and females and reproduce them; helps determine which parents to breed (broodstock), where to release offsrping, what traits to select for

can help determine speces vs subspecies

act like a natural tag for movement or migration of species

Species vs subspecies; hybrid vs stock vs strain

species = naturally occurring group of organisms that successfully interbreed

subspecies = a geographic subdivision of species

hybrid = two different species mix, offspring may or may not (more common) reproduce

stock = pop of a single species w/ limited reproductive mixing and similar biological characteristics

strain = similar genetics used in propagation (typically have diff phenotypes

Define fitness, plasticity, and selection in fisheries/wldf

Fitness = ability to pass on genes and for offspring to reproduce

plasticity = the ability to change a phenotype based on environment (diff colors or behaviors, ex)

natural selection: successful traits will increase while less successful will decline

inbreeding vs outbreeding

inbreeding = reproduce w/ genetically similar individuals; decrease genetic diversity and fitness, is more likely in small pop., but local adaptations

outbreeding = reproduce w/ genetically distant individuals; increase genetic diversity but reduce fitness; lose local adaptations

What is a wetland? (3 H’s)

transition between terrestrial and aquatic systems, water table is at or near the surface, the land is covered at least part of the time by shallow water

Hydrology - theres there water there at some point?

Hydric soil - anaerobic soil that has specific characteristics to wetlands

Hydrophytes - plants that have roots submerged in water throughout parts of year

Importance of wetlands in general?

40% of global species depend on wetlands for at least part of life cycle

25% of marine life depend on coral reefs and estuarial wetlands

46% of US endangered species are associated with wetlands (b/c historically, US has lost tons of wetlands ex. 91% in CA or 47% in WI)

Importance of wetlands for fish/wildf?

spawning, fish nurseries, reproduction for animals (especially birds), migration stop over sites for refueling

Importance of wetlands for ecosystem services?

water storage —> mitigate flooding, wave action, and erosion

hold sediment and nutrients to improve water quality

sequester atmospheric carbon

recharge groundwater

stabilize shores and streambanks

shade streams —> keep them cool for cool and cold water fishes

Ways to manage wetlands for wildlife benefit? (2 ways)

Flooding - increase open water and deepen pool, control invasion of woody species, attract water birds

• hemi-marsh is ideal mix with 50% water and 50% emergent vegetation

drawdown - lower water levels to encourage growth of moist soil plants

• allows for their germination, especially annual plants that reproduce with lots of seeds

• releases nutrients to system, get oxygen into system, promote decomposition

• attracts shorebirds and terrestrial wldf that want water only as deep as their legs go

• especially beneficial during migration seasons for food and cover of wldf

Describe the specific type of wetland that’s helpful for fish like pike?

ephemeral wetlands: only wet for part of year (like spring and early summer) then dry up as temp and growth of plants increases

• critical habitat for fishes, amphibians, reptiles, but not bigger fish

• not many predators

• vulnerable to loss b/c no protected by clean water act

Pike use of ephemeral wetlands:

• migrate up streams, lay eggs, leave

• eggs hatch and the fry connect selves to vegetation as they grow

• when 12mm, they leave also