NRES 421 Study Guide

19. Briefly describe the Tilman experiments we discussed in lecture and what they tell us about 'diversity-stability' and 'diversity-function'.

Diverse plots are stable, and vary less over time. Diverse plots increase biofuel. Plots with 2,4,8,16 species increased biofuel production 84, 100, 157, 238% more than monoculture. Experiments created plots on depleted soil, in various plots, with more or less species. Positive relationship between richness and carbon sequestering.

7. What are the hierarchical levels in which diversity is organized and which level tends to receive the most attention in conservation? Do you see that particular focus as a strength or weakness, why?

Ecosystem, Community, Species, Population, Gene The species level receives the most attention in conservation because they are the fundamental components of biodiversity. The focus on species is both a strength and a weakness. Species diversity contributes so much to the natural world. If we lose focus on species, there is almost no point to conservation. A human-centered world will not survive without species diversity. Each hierarchical level supports the other. If we place too much focus on one level we may lose critical insight from the others which could potentially help us strengthen species diversity.

55. Explain Elton's "Biotic Resistance Hypothesis". Assuming this relationship exists, draw what you would expect to observe in communities with varying levels of species richness (x-axis) and occurrence/incidence of an invasive species (y-axis).

Environments with diverse species are more resistant to invasive species because the environment is more able to efficiently use their resources

44. What is an extinction debt? Provide an example. How does this concept help guide conservation efforts?

Extinction debt occurs because of time delays between impacts on a species such as destruction of habitat, and the species ultimate disappearance. An example of this concept is predicting the pattern of decline of African primate diversity due to historical deforestation.

24. From examination of past extinction events, there appear to be at least some life history/ecological traits that are correlated with extinction risk. Name 4 of these and their general relationship with extinction risk. Feel free to use simple graphs with labeled axes to present your ideas. Choose one of these general trait-extinction risk relationships and describe a species that either does or does not conform to the general relationship you describe.

Geographic range describes the spatial area where a species is found. Home range is defined by the interaction between animals and the environment, Trophic Level is the position of an organism in the food chain Habitat Specialization defines species dispersal ability and thus the degree of isolation of populations.

40. Draw the classic ETIB model as presented by MacArthur and Wilson with labeled axes and rates of colonization/extinction in small/large islands, near/far from the mainland.

Graph

26. What is the difference between habitat loss and habitat degradation?

Habitat Loss in impacts so severe that all species are somehow impacted. Degradation impacts some species, not all species, with the eventual possibility to restore the area.

30. Provide a succinct definition of habitat fragmentation.

Large expanse of habitat, transformed into smaller, isolated areas, unlike the original. Discontinuity of resource distribution that affects survival of species.

17. We discussed 4 hypothetical relationships between species richness (as a measure of diversity) and ecosystem function. Graph them and provide a brief interpretation of each.

Linear: Richness increases as function increases, and vice versa. The least probable relationship. Rivet: Richness does not increase until it hits a certain level of function. Redundancy: Richness evens out when function is at its peak. Idiosyncratic: Richness and function show no discernable pattern.

21. Cardinale et al. 2012 present several "consensus statements" that emerge from decades of studies concerning the relationship between biodiversity and ecosystem function. Discuss at least two of these points.

Loss of diversity across trophic levels has the potential to influence ecosystem functions even more strongly than diversity loss within trophic levels. This statement goes along with the idea of how important food web interactions are. Loss of a top predator can reduce biomass at lower levels Diverse communities are more productive because they contain key species that have large influences on productivity, and differences in functional traits among organisms increase total resource capture.

38. Why is it important to consider edge effects in assessing habitat availability?

Most pervasive and damaging effects on biota came from edge effects. Matrix can exacerbate edge effects. Matrix type may differ in resistance to movement of individuals of certain species groups.

33. List 4 ways in which habitat fragmentation differs from natural heterogeneity.

Natural landscapes are divided into patches; diversity in habitats are in dynamic equilibrium, species may or not be able to adjust to rapid change. Patches and matrix in natural habitats tend to have complex internal structure, matrix tends to be simplified. Contrasts are more intense in fragmented habitats.

32. What is a "patch"? What is the "matrix"?

Patch is a native habitat that is undeveloped. Matrix is entirely inhospitable, outside the area of the patch.

31. What do McGarigal et al. (2005) suggest are the characteristic steps in the progression of habitat fragmentation? Briefly describe each.

Perforation: small holes of development. Dissection: connecting small holes with roads and other development. subdivision: Habitat becoming physically subdivided. Shrinkage and attrition: Each group of development consistently increases area of development.

49. The pigs and foxes on Santa Cruz Island provide an example of "apparent competition" or "hyperpredation". Describe the trophic dynamics on these islands that lead to this situation.

Pigs were introduced to the island for food,the pigs ate the skunks which caused the fox population to decline, also due to the golden eagle the fox population dropped, removing the eagles allowed the fox population to be stable. Eradicating pigs and eagles was the best way to sustain the foxes.

37. Show a simple graph of how an organism or other "response variable" might respond to the different conditions at fragment edges? Provide a biological or ecological example of each.

Positive, neutral, and negative (response variable y axis, distance to edge x axis). Positive example is young trees establishing at edge due to more sunlight. negative example is a reduction in cover for prey species at the edges.

34. Describe a way of quantifying habitat fragmentation and what characteristics of fragmented habitat they are intended to reflect.

Proximity indices are a method of quantifying habitat fragmentation, they account not only for the diversity in sizes of different patches but also the relationship between inner patch distances among the area.

51. Describe Dr. Vredenburg's fish removal experiment and the results. Briefly discuss the biological and economic management implications of his findings.

Removal of introduced fish led to rapid recovery of the declining frog population. Dr.Vrendenburg removed all fish from a frog lake and relocated them to a lake with just fish. The frog lake with removed fish saw an increase in the declining frog population.

41. From the basic ETIB model, compare species richness and turnover rates in small-far and large-near islands.

Small-far islands will have the lowest number of species, and an intermediate rate of turnover. Large nearby islands will have the largest number of species, with an intermediate number of turnover.

39. What three key pieces of information did MacArthur and Wilson have in hand as they began to develop their ETIB?

Species area relationship, species isolation, species turnover

10. Name and briefly describe three different metrics of biodiversity on which hotspots have been based (e.g. Myers et al. 2000; Ceballos and Ehrlich 2006). Provide one pro and one con to using each of these.

Species richness, endemism, threat level

11.Describe three ways that biodiversity hotspots have been identified in the literature highlighted in lecture, what is the cautionary suggestion from Ceballos and Erlich 2008?

Species richness: This approach identifies hotspots based on the number of species found in a particular area, with a focus on regions with high levels of both species richness and endemism. Endemism: This approach identifies hotspots based on the proportion of species that are found only in a particular area and nowhere else in the world. Phylogenetic diversity: This approach identifies hotspots based on the evolutionary diversity within a particular area, taking into account the number of species and their evolutionary relationships. Therefore, while species richness, endemism, and phylogenetic diversity are all useful metrics for understanding biodiversity, they should be considered as part of a larger, more holistic approach to biodiversity conservation.

45. Briefly describe the experimental design of the Biological Dynamics of Forest Fragments Projects. What was this project designed to test or examine? What are the major conclusions of this experiment in terms of area, isolation, edge effects and matrix?

Studied 11 different fragments with 12 controls of varying sizes in order to determine minimum size for rainforest reserves to maximize conservation of biodiversity. it was determined that the most damaging effects on the systems came from edge effects, and that Matrix surrounding the fragments altered the composition and ecosystem dynamics within the fragments

28. How did the Aral Sea change in size from 1964 to the late 2000s? Why did this change occur? List at least 4 biological, ecological, or commercial/economic outcomes of this change.

The Aral Sea was dried out because it lost its primary water inlet. Water was diverted to sustain a cotton industry. This led to 60% of the human population losing drinking water, Led to collapse of fishing, cotton, and meat industries, Collapse of aquatic species due to increasing salinity, Higher concentration of minerals in water.

14. What does the Rarity-Weighted Richness Index aim to capture in terms of overall biodiversity and how would this measure help you prioritize your conservation efforts?

The Rarity-Weighted Richness Index combines alpha and beta diversity into a single number and weighs the level of rarity for the species in the area.Areas with a larger RWRI should be prioritized higher for conservation efforts. Rarity-Weighted Richness Index is a way to identify sites that represent all species in the fewest number of sites or to identify sites that represent the largest number of species within a given number of sites. Using this index can help you prioritize conservation efforts because you will be able to see which sites have lower abundance compared to other sites.

2. Name and describe three major schools of thought that have shaped American conservation biology since the 1800's. Provide the name of at least one person that is associated with each.

The Romantic Period emphasized the spiritual and aesthetic value of nature and "wildlife" (Ralph Waldo Emerson) The Resource conservation Ethic focuses on the efficient, scientifically informed management of nature for human benefit (Theodore Roosevelt) The Evolution Ecology Ethic focuses on natural communities that are worth Preserving without reference to any derived human benefit (Aldo Leopold)

3. Compare and contrast the three major schools of thought that shaped American conservation biology since the 1800's.

The Romantic and Resource conservation thoughts are both essentially human centered focused on Protecting the wilderness. The Evolution Ecology ethic has a scientific focus on management and conservation approach. The application of scientific Principles makes the Evolution of Ecology Ethic different from the other thoughts.

4. In the Channel Island example we discussed in class, how would you answer the high school teacher's question : Why the pig? Provide at least 4 points.

The pig has an overall negative impact on the ecosystem in more than just an individual level, it is also exotic to the ecosystem and doesn't naturally belong there, the fox is also being threatened by the pig and at risk of extinction, and is the natural endemic species.

15. What does the Shannon Index aim to capture in terms of overall biodiversity and how would this measure help you prioritize your conservation efforts?

The shannon index displays species richness in terms of evenness. It can help prioritize efforts as it can identify areas that may have high species richness yet low evenness, which can help account for misleading data.

52. Orians (1994) coined the term 'Homogocene' to describe the era that we are currently in. What is he trying to describe with this term and how might you measure the existence of this phenomenon?

The term homogocene is described as humans have broken global barriers allowing species to move between masses and aquatic environments in a way they could not before. increases the alpha diversity but decreases the beta diversity

1. Approximately how many humans are on the planet today? What is the historical trajectory of human population growth and how does this relate to the field of Conservation Biology?

There are almost 8 billion humans on the planet today. Human population has been growing exponentially. It relates to conservation biology as increasing human populations leads to greater invasion on ecosystems by humans and environmental impacts.

23. Brook et al (TREE 2008) present different models of how individual threats can lead to biodiversity loss. Briefly describe the different potential relationships between threatening processes as presented by these authors. You can use a simple graph to present your ideas.

They stated that certain threats to biodiversity can have synergistic effects, leading to a positive feedback loop creating greater negative impacts than simply adding threats together when threats are occurring simultaneously.

Conservation biology is often viewed as a "crisis-discipline". List three characteristics of the discipline that accompany this description. Name at least one benefit and one drawback of continuing to promote Conservation Biology as a "crisis-discipline".

Three characteristics of crisis discipline are acting before knowing all the facts, response to environmental change, and having a holistic approach. One drawback of promoting conservation biology as a "crisis discipline" is that there is some uncertainty in taking action before knowing if it is the right thing to do.

5. From Soule 1985, what are at least 3 primary defining characteristics of the field of Conservation Biology? Provide a brief statement describing each.

Three characteristics of the field of conservation biology are its similarities to other crisis disciplines, the nature of resources, targeting a small number of resources to have larger scale impacts, and time scale, often having to make decisions on time scales much longer than desired or that we have the ability to predict.

27. What habitat/region(s) are projected to experience the most habitat loss by 2050 and why is this of particular significance to biodiversity?

Tropical, subtropical coniferous forest. Tropical grassland. Tropical, broadleaf forest. This is significant because these areas have the highest levels of biodiversity.

8. While only one level in the hierarchy of life, provide two reasons why much of our conservation efforts focus at the species level.

We focus on the species level the most because out of the domain kingdom species are the level we know the most about, and species level information shows trends both in the higher and lower levels.

43. How can the ETIB be applied to conservation?

1 Identifying restoration targets to add area or reduce isolation 2 Understanding dynamics of protected areas 3 Identifying expected change in species richness with habitat loss

58.When pets/domestic species become invasive it can lead to conservation conflicts. Describe such an example, the conflict it generates and what solutions you suggest.

When it comes to pets/domesticated species becoming invasive it can lead to conservation conflicts. An example is free-ranging pet cats and unowned feral cats killing 1.3-4 billion birds and 6.3-22.3 billion mammals annually. A solution could be to minimize mortality from all anthropogenic threats are needed to increase sustainability

18. Why does the shape of the "diversity-function" and "diversity-stability" relationship matter in terms of the consequences of biodiversity loss?

depending on the shape of the relationship, there can be a different range of stability and function loss with the loss of species richness. ecosystems could also potentially have thresholds in which stability and function are relatively unaffected by diversity loss, but have greater effects once the threshold is crossed

46. Early et al. (2016) show differences in global/regional threat of invasive species. How does this paper go on to describe the differences among countries in terms of their ability to respond to these pressures, and why do these differences exist?

different countries have different levels of ability to combat invasive species within their region. Different countries also have differences in the extent of knowledge surrounding invasive species and how to deal with them

25. Describe/draw the "extinction vortex" as a way to link various threats to biodiversity through the population dynamics that might lead to local extirpation or extinction.

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42. Using a graph, demonstrate how the species-area relationship helps estimate the extinction debt? Use a graph of this relationship to present your answer.

graph

57. Describe an example of the multiple roles that invasive species might play in communities and how that challenges a simple "invasives = negative" viewpoint.

invasive species could provide benefits to some species while still being detrimental to others, an example is eucalyptus trees with monarch butterflies. Monarch butterflies rely on eucalyptus trees during their migration, even though they are an invasive species they assist the butterflies on their migration.

54. Using cheatgrass as an example, describe at least one ecosystem-level change that is being caused by this invasive species. Does this alteration change the invasibility of the grassland community? If so, how?

one ecosystem level change is the homogenization of species within the system. Cheat grasses ability to reestablish faster than its competitors following disturbance (fire) leads to a positive feedback loop which is shifting the distribution of species within the system. it changes the invisibility of the grass land community by making it more suceptible.

22. Johnson et al. 2017 in their article "Biodiversity losses and conservation responses in the Anthropocene" suggest that there are four reasons that past conservation efforts have failed to substantially slow the loss of biodiversity. List these four reasons.

1 Responses to biodiversity decline are being more than offset by rising pressures, related ultimately to increasing human population 2 Interactions and synergies among threatening processes often amplify their effects, producing large and accelerating combined impacts. 3 Funding for global conservation is inadequate =. Total world spending on conservation for the period 2001-2008 was estimated at $21.5 billion per year 4 In most societies conservation is not mainstreamed to economic and social planning and human behavior

48. What are 3 types of interactions that invasive species often have with native species? Provide an example/case that demonstrates each of these.

1. Predation - brown tree snake, the snake population grew out of control and ate a lot of the species on the island. Only invasive species survived 2. Competition - Argentine ant and harvester ant 3. Trophic cascades - argentine ant and coastal horned lizard

35. Franklin et al 2002 suggest that it is important to correctly categorize how habitat is being altered, what 4 cases do they distinguish?

1:Habitat loss without fragmentation. 2:Habitat loss with fragmentation. 3: Fragmentation. 4: Edge effects, fragmentation, change in habitat quality.

46. Dirzo et al. 2014 list a number of consequences of defaunation on ecosystem functioning and services. Explain two of these examples.

reduced seed dispersal, reduced herbivory, reduced carbon cycling. when fauna are removed from the system, there is dramatic declines in the rates of seed dispersal and herbivory rates.

56. Considering resource use and resource availability in a community, what type of changes in these parameters might increase the invasibility of a community?

the greater the resource availability of an ecosystem is to its resource use makes a community more susceptible to invasion. The more resources available yet not being used creates a niche that an invader could occupy within a system.

36. Provide a succinct definition of "edge effects". List four environmental or biological characteristics that might differ between edge and core habitat.

the physical and biological effects associated with the abrupt, artificial boundaries of habitat fragmentation, four characteristics that might differ between edge and core are Temperature, Humidity, Wind, and presence of Invasive species

50. What is the history of fish stocking in the Sierra's and why weren't fish introductions initially suspected as being a major cause of decline in frogs?

trout started being stocked in the lake 1890s and there were already native trout in some areas they thought the fish weren't the problem because the frogs declined in 1970 and the trout were introduced in 1890, and trout were native in some areas

42. What is the Allee effect? Provide a brief example of such an effect in a population.

Allee effects are broadly defined as a decline in individual fitness at low population size or density, that can result in critical population thresholds below which populations crash to extinction.

12. How are alpha, gamma, and beta diversity estimated. What do these measures tell us about how diversity is spatially distributed and how might they be used in conservation planning?

Alpha- species richness, local focus area. Count the number of species in the focus area and take the average. Mtn example, from class. Gamma- total number of species across a larger area that encompasses individual focal areas- regional perspective of species count. Mtn example. Beta- Metric of turnover from spot A to spot B. Community variation from mtn range 1 to mtn range

47. What is an invasive alien species?

An invasive alien species is a species found outside of its native range and having some negative economic or biotic impact.

29. According to research done by Dr. Tyrone Hayes, how does the pesticide atrazine impact individual frogs at various developmental stages and what are the population-level implications?

Atrazine shrinks reproductive organs, and produces a teste/ovary tissue. Frogs become hermaphroditic, males stopped producing testosterone, and feminized. Caused a low reproductive output. This was at levels of atrazine found in normal water.

9. Where will most of the changes in our current understanding of taxonomic diversity come, that is, which groups are currently the most poorly described?

Bacteria, only .5% described. Viruses, 1% described Fungi, 5% described Nematoda, 6% described Bacteria is the group currently most poorly described

20. Describe an indirect ecosystem service and what would have to be put in place by humans to replace this service.

Bee pollination is a natural process, and can be replaced by human induced pollination, however this is much more costly and less effective.

13. What is beta-diversity? Name 4 ways highlighted by Socolar et al. 2016 that beta-diversity might change with human disturbance. Provide an example for each of these possible categories of change.

Beta diversity reveals the spatial scaling of diversity loss. Human activities cause beta diversity to increase, decrease, and remain unchanged. 4 ways that beta-diversity changes with human disturbance is intensive farming and agriculture usually erode beta diversity, beta diversity can change has a result of local species gain and local losses, Beta diversity decreases when rare species become extinct, and Large scale fishing also has a direct impact on beta diversity.

6. What is a succinct definition of biodiversity?

Biodiversity refers to the variety and variability of life on Earth, including the diversity within species, between species, and of ecosystems.

53. What 'filters' does an exotic species have to overcome in the process of establishing itself in a new community? Which of these filters is particularly impacted by humans and how?

Biogeographic, physiological, and biotic filter. humans particularly impact the biogeographic filter, aiding in the dispersal of different species around the world out of their native ranges.