Biodiversity - Midterm 2

Why has there been a change in language from "global warming" to "climate change?"

Because not all extreme climate events have to do with warming or heat

Costs of invasive species estimated at approximately _________ in the United states, which may even be an underestimation. These costs include:

$120 billion - Damage caused by invasive species: loss of good habitat, animals grazing - Changes to ecosystem processes: water filtration, nutrient cycling - Changes to aesthetics and recreation: organisms making parts of the environment less pleasant - Management costs: how much it costs to get rid of the invader

Fire ants have cost a total of __________________, with _________________ of that total being solely control costs including treatment and quarantine of infected areas, and providing baits and insecticides.

$600,000,000 $400,000,000

What are the two main methods of introducing a non-native species to an area?

(1) Accidental introduction (2) Intentional introduction

Agricultural, aquacultural, & horticultural introductions of new species are instances of intentional introductions for the purpose of:

- food - resources - ecological function - sport - aesthetics

What populations in particular are especially vulnerable to invasions and the associated negative impacts? Why?

- islands already have a higher extinction rate due to a limited amount of resources and fewer places to find protection from predators - species on islands become naïve to predators because they have only been exposed to a limited range of predation

How do invasive plants have an impact on ecosystem processes?

- Alter nutrient cycling, decomposition, and many other soil properties --> in some cases, a positive effect of invasion can be observed because the invasive species need to do some of those processes for themselves as well (i.e. use of nitrogen) - Change in disturbance regimes, semi-cyclic processes that are necessary for the health of ecosystems such as regular fire burns to maintain healthy grasslands

How are terrestrial invaders accidentally introduced to an area?

- Attachment to packing material - via commercial & individual travel

What are the negative impacts of fire ants and why do we spend so much money to keep them away?

- Bites to humans (+ associated medical costs), which can cause pain, anaphylaxis, or death - Death to poultry

What are the anthropogenic sources of CO2?

- Burning of fossil fuels - Deforestation - Production of cement

Greenhouse gases include:

- CO2 - Methane - Nitrous oxide - Fluorinated gases

According to the Strayer et al. paper "Understanding the long-term effects of species invasions" (2006), how can invaders affect the abiotic environment?

- Causing the extinction of ecosystem engineers can decrease structural integrity and diversity of a community - Might even increase nutrient cycling

According to the Strayer et al. paper "Understanding the long-term effects of species invasions" (2006), what are the processes that can alter the effects on invasions over time?

- Changes in the species that is doing the invading - Changes in the invaded biological community: composition of species in the area, quickly or over time - Changes in the abiotic environment: nitrogen cycle, nutrient cycling - Interactions between invasive species and other variables

Mechanisms whereby invasive species cause harm include:

- Competition for resources - Predation and parasitism - Changes in ecosystem processes - Alteration of abiotic conditions

Biotic resistance hypothesis

- Diverse, undisturbed communities are less vulnerable to invasion whereas disturbed communities with few species are more vulnerable to invasion

What are some examples of naturalized species in North America? What do these examples suggest?

- Earthworms - Horses (evolved in NA, went extinct, and then were reintroduced) - Honeybees (no native lineages from the continent of NA) - Apples - Humans These examples suggest that being a naturalized species is not necessarily bad, and that many naturalized species make positive contributions to ecosystems and the economy.

General characteristics of invasive species

- High dispersal rates --> able to quickly spread when they get to the new environment - High rates of population growth - Large native range --> if they have a large native range, they can translate this to a large non-native range - Successful in disturbed environments - Has invaded another area before

According to the Strayer et al. paper "Understanding the long-term effects of species invasions" (2006), what traits might make native species more likely to evolve in response to invaders?

- Higher reproduction rate - Large population size (large gene pool) - Ability to use the invasive species in some way (being a naturalist, using the invasive species as a source of food, etc.) - Resilience of the species

Naturalization hypothesis

- Introduced species are less likely to establish in communities where there are native congeners - native congeners can act as strong competition against the necessary resources, because if they are congeners then we are assuming they have similar resource requirements

What needs to be considered when deciding if a species is likely to shift from naturalized to invasive?

- Life history - Mobility - Habitat

Biotic acceptance hypothesis

- Opposite of biotic resistance hypothesis - Assumes that conditions that are good for native species are also good for non-native species

Invasive species change ecosystems, sometimes for the better. What are some of the positive functions of invasive species?

- Provide food - Provide shelter - Increasing ecosystem services - Replacements for extirpated species

What are the natural sources of CO2?

- Release from marine ecosystems - Plant & animal respiration - Decomposition

According to the Strayer et al. paper "Understanding the long-term effects of species invasions" (2006), how do invasions affect community composition beyond changes in species richness?

- Species composition within invaded communities can shift over the long-term towards species that are resistant to the effects of the invader. - Predators, parasites, and diseases of the invader might arrive/proliferate

How are freshwater invaders accidentally introduced to an area?

- aquaculture escapes - Hitchhiker species (like Zebra mussels that stick to the side of a boat)

Enemy (predator) release hypothesis

- the population of a species is kept in check in its native habitat by the predators that live there, so when the species is removed from its home environment, the predators (enemies) are absent so the species is able to grow unrestricted - there is mixed support for this hypothesis because it really does depend on the species in question

According to the IPCC report, with global warming of 1.5°C, sea levels are projected to rise by how much?

0.26-0.77m by the year 2100

Mean global temperatures have increased by about ________ degrees Celsius (_____ degrees F)

0.85 (1.53)

What are the two categories of intentional introduction?

1) Agriculture, aquaculture, & horticulture 2) Biological control

What are the different hypotheses for predicting the invasiveness of a species?

1) Enemy (predator) release hypothesis 2) Naturalization hypothesis 3) Biotic resistance hypothesis 4) Biotic acceptance hypothesis

What are the 3 general approaches to the removal of invasive species?

1) Pesticides 2) Mechanical culling 3) Biological control

Levels of arctic sea ice are clearly declining, and the decrease has been happening since ___________.

1980

Without greenhouse gases, the earth's surface would be approximately how much cooler?

33 degrees C (~60 degrees F)

The threat posed by invasive species is _______, behind: (in terms of decreasing biodiversity)

3rd - Habitat loss/degradation (#1) - Overpexploitation

According to the Strayer et al. paper "Understanding the long-term effects of species invasions" (2006), what are the advantages/disadvantages of acclimatization vs. evolution of invasive species?

Acclimatization: occurs much quicker and allows for a more immediate response, but it won't be inherited by the offspring, occurs within the lifespan of an individual, important for responding to the biotic and abiotic changes that occur later in the invasion process Evolution: allows for inheritance of the preferred trait by offspring, which is particularly helpful when a trait has been favored by natural selection and has a high allele frequency, permits increase in population size and range, BUT there is a lag between when the invader arrives, and when the evolution has gotten to the point of being beneficial

What is the difference between acclimatization & evolution?

Acclimatization: phenotypic plasticity, change within a short period of time that is NOT passed on to the offspring Evolution: changes in allele frequency in a population as a result of natural selection where changes ARE passed on to the offspring

According to the IPCC report, which of the following INCORRECTLY interprets the risks of increasing temperatures associated with selected natural systems? A) Mangroves will experience moderate risks at temperature increases of 1.5°C. B) Arctic regions will experience higher risks than other terrestrial ecosystems and those risks will happen at lower temperature increases. C) Fluvial (river) flooding is predicted to be more severe than coastal flooding as temperatures rise. D) Relative to other natural systems, warm-water corals are predicted to be at the greatest risk as temperatures rise. E) All of the above are correct interpretations.

C) Fluvial (river) flooding is predicted to be more severe than coastal flooding as temperatures rise.

Hybridization

Closely related invasive species invade an area and interbreed with the native congener, which can lead to the extinction or extirpation of the native species --> this can be a significant cause of extinction in vulnerable native species.

Within a country, what areas are experiencing the least amount of temperature change?

Coastal regions

What is the Keeling Curve? What trends has the curve shown?

Daily measurements of CO2 levels since the 1950s --> there has been a clear increase in the amount of CO2, and although monthly levels of CO2 fluctuate the trend since the 1950s is an increase

The impact of invasive species on native species can be broken down into direct or indirect effects. Provide examples of both.

Direct effects: predation, parasitism Indirect effects: competition for resource, transmission of disease, changing the environment

According to the IPCC report, a key approach to limiting global warming to 1.5°C is changing the way we use and produce energy. Which of the following strategies is NOT included as an approach to keeping global warming at 1.5°C based on current models (pathways)? A) Increasing use of nuclear energy with associated carbon dioxide capture and storage technology. B) Increasing use of fossil fuels with associated carbon dioxide capture and storage technology. C) Increasing sources of renewable energy so that they account for the majority of electricity produced. D) Lowering overall energy use. E) All of these are suggested as strategies.

E) All of these are suggested as strategies.

Discuss an example in which a species can take on different roles (invasive vs. naturalized) depending on where it is geographically.

Eastern US: Linaria vulgaris is naturalized (non-native and does not have negative effects) Western US: Linaria vulgaris is a harmful, invasive species

How does climate change affect vulnerability to invasion?

Global climate change has increased the susceptibility of habitats to invasion

Differentiate between the terms "global warming" and "global climate change."

Global warming: the term used to describe the rise in temperatures resulting from the increase in greenhouse gases Global climate change: the term which refers to the complete set of climate characteristics that are changing now and will continue to change in the future because of this increase (includes precipitation and wind patterns)

Looking at global temperature trends, where have the greatest and least temperature increases been?

Greatest: northern polar latitudes Least: over open ocean

How and why are greenhouse gases actually a good thing in terms of maintaining our climate?

Greenhouse gases trap heat leaving the earth's surface which regulates global temperatures and provides our atmosphere

Why have there been so many studies focused on hypothesizing/predicting whether or not a species will become invasive?

If we are able to predict the shift from introduced to invasive before it happens, we can possibly prevent it or at least start to think about how the situation could be mitigated.

Discuss an example showing that there are different proportions of native vs. non-native species depending on where you are in the world.

In Asia, the majority of plant species are native to Asia. But in North America, about 50% of plant species are native while the other 50% are non-native.

What is the relationship between the amount of introduced species and vulnerability of a native species to extinction? Provide evidence that we learned in class.

In areas where there are a lot of introduced species, there are more species that are vulnerable to extinction. Freshwater basins with high proportions of non-native fish species had more threatened native fish species. - Note that this study was considering INTRODUCED species, not necessarily INVASIVE.

According to the IPCC report, when is the global temperature predicted to reach 1.5°C above pre-industrial levels?

In as few as 11 years (between the years 2030-2052)

According to the biotic resistance hypothesis, what happens to the abundance of invasive species as the native species richness increases?

Invasive species abundance decreases

What are the invasive traits of purple loosestrife? What is its major impact?

Invasive traits: - Can grow clonally - Produces millions of tiny seeds - Seeds carried by wind & water - Can reproduce vegetatively Major impact: - Crowds out native plants

What are the invasive traits of kudzu? What is its major impact?

Invasive traits: - Clonal growth - Drought-tolerant - Can grow in nutrient-poor soils (because it is a nitrogen-fixer) - Can grow up to 60 feet per year Major impact - Smothers native plants - Increases ground-level ozone

What are the invasive traits of fire ants? What are their major impact?

Invasive traits: - Large colony size - Fast growth rate - Can survive extreme conditions, including cold and floods - Strong defenses Major impact - Injure & annoy humans

What are the invasive traits of the snakehead fish? What is its major impact?

Invasive traits: - Produce up to 50,000 eggs - Generalist consumers - Can migrate over land - Aggressively defend offspring - Have large potential range in the US Major impact: - Top predators in freshwater ecosystems

What is the relationship between changes in species richness and habitat being invaded?

It also varies, but terrestrial habitats tend to be more negatively impacted which suggests they may be particularly vulnerable to invasion and the negative effects of invasive species.

What is the relationship between changes in species richness and the taxa/trophic level of the invader?

It is really varied among taxa, ranging from very negative changes to very positive changes.

According to the enemy release hypothesis, will a species have more potential enemies (pathogens, predators, etc.) in its native range or naturalized, non-native range?

Native range

Sources of greenhouses gases (CO2) can be categorized into what 2 types of sources?

Natural sources & Anthropogenic sources

Biological control

One species is introduced to control the population of another, usually one that is interfering with human activities

What is the perception of invasive species in the public sector?

People generally know that they are not good for an ecosystem, and a lot of dramatic language has been used to describe them

The IPCC created predictive models called ________________________, which project future climate conditions based on different potential emissions scenarios.

Representative concentration pathways (RCPs)

- One of the most invasive plants in the southwest US - Extirpates native plants, reduces water levels, changes soil conditions - Has become key nesting habitat for the endangered Southwest Willow Flycatcher

Tamarisk

Describe the greenhouse effect.

The denser the concentration of greenhouse gases, the more heat gets trapped near the earth so the higher its surface temperature is.

Why is climate change a controversial topic?

There are debates on whether humans are causing the climate change or whether it is something that is naturally occurring.

What trend is made clear when global temperatures and CO2 concentrations since the 1900s are graphed together?

There is a clear correlation between the increasing levels of CO2 and increasing global temperatures.

What patterns of average ocean temperatures are seen with regard to ocean depth?

There is a greater and quicker increase in the temperature of surface levels of water than the deeper levels

Patterns of species introductions around the world suggest what about the total cumulative number of invasive introduced species? (Which countries have the most invasive species?)

There is a higher quantity of invasive species in "New World" countries like USA and Australia, and those in the Western Hemisphere --> USA has the most amount of invasive species

When we look at data showing the cumulative number of non-native species, why do we see a spike around the 1800s?

This was the period that directly preceded the introduction global travel.

Differentiate between weather and climate.

Weather: short-term patterns of temperature or precipitation, tells us what is happening within the next 10 days or so Climate: long-term patterns, average temperatures or precipitation levels, on the scale of years (sometimes months)

When can the presence of invasive species actually be a good thing?

When the habitat is so degraded that the original species are unlikely to re-establish themselves Ex: plant species that stabilize eroding lands, provide nectar for native insects, or supply nesting sites for birds and mammals

Invasive species

a species with such high abundance that it affects other species, habitats, or ecosystems

Naturalized species

an introduced, non-native species that becomes established in a new environment and is able to persist; can be invasive but does not have to be considered as such (can still develop to become invasive over time)

Global temperature increases have not been _____________. Some areas have seen a temperature increase of more than _______ degrees C.

uniform 4

In addition to rising sea levels, what can be said about ocean pH levels?

as CO2 levels are increasing, ocean pH levels are decreasing (ocean is becoming more acidic)

How are marine invaders accidentally introduced to an area?

ballast water from ships --> water is pulled up from one part of the ocean and then dumped in the next port

Agricultural, aquacultural, & horticultural intentional introductions initially exist under ________________ conditions, but what can happen?

controlled --> individuals can escape, establish, and become invasive

Humans are ___________ responsible for increasing atmospheric CO2, and ____________ responsible for rising temperatures.

directly indirectly

What is basically the worst consequence of an invasion of a non-native species? Discuss evidence that we learned in class for this.

extinction of the native taxa --> Researchers looked at 170 animals that had gone extinct, and 54% of those vertebrates were extinct in part or entirely due to an invasive species in their native range

Organism that was accidentally introduced to the US in 1930s through a seaport in Alabama and has gradually spread through the southern states

fire ants

The highest concentrations of invasive species are often found in those habitats that have been most altered by:

human activity

Why does the vast majority of species migration/movement occur? (Particularly for the flow of plant species between continents).

human interaction

What type of area is considered a hotspot for invasive species?

islands (and isolated habitats in general)

Plant introduced in 1876 as ornamental, and for use as fodder and erosion-prevention --> removed as a suggested cover plant in 1950s and listed as a weed in 1970s

kudzu

The rate of becoming an invasive species is _____________ than the rate of becoming a non-native, introduced species.

lower

There is currently _______ single mechanism to predict invasion or invasiveness.

no

Introduced, exotic, or alien species

non-native species that has crossed a large barrier to dispersal, probably due to human influence (e.g., oceans)

Virginia invasive plant species that was accidentally introduced to the US in the 1830s through a ships' ballast and was used as an ornamental plant ---> seeds spread by themselves and as hitchhikers along canals and roadsides

purple loosestrife

Virginia invasive species that was permanently established in the Potomac by 2004 after being spotted spawning in a pond in Maryland in 2002 (it may have been imported for food/pet trade but escaped)

snakehead fish

What is a garden experiment and why are they helpful?

take plants that grow in various types of environments and grow them in the same environment --> allows us to observe differences that are due to genotype and evolved differences rather than changes made due to phenotypic plasticity

Meta-analysis

taking data from many different studies that have different units and converting the data to a standardized metric to measure effect size rather than individual changes in richness

Looking at data showing the number of naturalized species in an area, what stands out about North America? Why is this?

the accumulation of naturalized species in North America has occurred more quickly than for other countries, largely due to the amount of human interaction in the area

According to the biotic acceptance hypothesis, what should happen to biodiversity in invasive species when the biodiversity of native species increases? Why?

the biodiversity of invasive species should increase as well --> conditions that are good for supporting biodiversity in native species would also support biodiversity in the invasive species

How can biological control backfire?

the control agent can jump to another species or start attacking multiple species which can be problematic when there is no mechanism to reduce population growth of the agent after desired control is complete

Why might adding detritivores to an aquatic ecosystem increase species richness?

they are responsible for breaking down nutrients for nutrient cycling

Mechanisms of accidental introductions depend on what?

where the invaders live

One of the best predictors of whether or not a non-native species will become invasive is:

whether that species has been invasive somewhere else before

The current levels of CO2 that we see now were last seen how long ago? What were the conditions then?

~26 MYA - Antarctic ice cap present - No large scale glaciation in North America - Temperature several degrees warmer - Sea levels tens of meters higher

When was the last time 1000ppm of CO2 was present? What were the conditions then?

~50 MYA - Temperatures were about 13 degrees C warmer - Earth was completely free of ice - Sea levels were >65m higher