BIO 117 Environmental Scince Notes 10 - Loss of Biodiversity

Average U.S. Intake

- 3,790 (UN Food and Agricultural organization 2004)

Biodiversity loss and its impact on humanity

- 9 million types of plants, animals, protists, and fungi inhabit the Earth. So do 7 billion people. - Earth is very biodiverse! - Here we review two decades of research that has examined HOW biodiversity loss influences ecosystem functions, and the impacts this can have on the goods and services ecosystems provide.

Key Point - Consensus 6

- Although diversity clearly has an impact on ecosystem functions when averaged across all genes, species, and traits, considerable variation surrounds this mean effect, stemming from differences in the identity of the organisms and their functional traits. - To predict accurately the consequences of any particular scenario of extinction, we must know which life forms have the greatest extinction risk, and how the traits of those organisms influence function.

Introduction of Species that become Invasive

- An invasive species is an organism that causes ecological or economic harm in a new environment where it is NOT native. - Most invasive species CANNOT adapt and will die off! - Rarely do we get species that can adapt - can displace native species, and outcompete them for food and shelter.

Ecosystem Functions

- Are ecological processes that control the fluxes of energy, nutrients and organic matter through an environment. - Example include: primary production, which is the process by which plants use sunlight to convert inorganic matter into new biological tissue; nutrient cycling, which is the process by which biologically essential nutrients are captured, released and then recaptured; and decomposition, which is the process by which organic waste, such as dead plants and animals, is broken down and recycled.

Ecosystem Services

- Are the suite of benefits that ecosystems provide to humanity. Here we focus on two types of ecosystem services - provisioning and regulating. - Provisioning services involve the production of renewable resources (for example: food, wood, fresh, water). - Regulating services are those that lessen environmental change (for example, climate regulation, pest/disease control).

Biodiversity and Ecosystem Services (BEF)

- BES research built on the idea that ecosystems provide essential benefits to humanity! - Main focus of BES was large-scale patterns across landscapes more relevant to economic or cultural evaluation. - Studies on BES were mostly correlative, conducted at the landscape scale and often focused on how major habitat modifications influenced "provisioning" and "regulating" services of ecosystems.

Why is there an increase in the total amount of food being produced each year?

- Because there are more humans born every year - More humans = more people have to be fed food

(BEF) Studies

- By the mid 1990s - BEF studies had manipulated the species richness of plants in a laboratory and field experiments and suggested that ecosystem functions, like biomass production and nutrient cycling respond STRONGLY to changes in biological diversity! - Research on BEF had developed a large body of experiments and mathematical theory describing how genetic, species and functional diversity of organisms control basic ecological processes (functions) in ecosystems.

Human Nutritional Needs: Sources

- Carbohydrates - Fats - Lipids - Sometime protein

Carbon Emissions

- Carbon emissions almost entirely come from the production stage! Less so for the food processing stage! - Plants produce low carbon emissions compared to meat, which produces high amounts of carbon emissions. - Lamb and beef are the highest in carbon emissions!

Why are fish continuing to be overharvested?

- Caused by poor regulations of fisheries! Fishermen are really good at fishing therefore if there are no set regulations on the amount they can fish, then overharvesting will become more frequent!

Cows

- Contributing to an increase in greenhouse gas concentrations - Have an organ called a rumen

Examples of habitat Degradation

- Deforestation - Decrease of productivity - Decrease the amount of resources that are available in the habitat. - Makes the habitat LESS SAFE and makes predation events easier to occur! - Certain species selected out for logging! - Insect loss from overuse of pesticides

Consensus Statement 4

- Diverse communities are more productive because they contain key species that have a large influence on productivity, and differences in functional traits among organisms increase total resource capture.

Emerging Trend 2

- Diversity effects grow stronger with time, and may increase at larger spatial scales. - Diversity effects in small-scale, short-term experiments may underestimate the impacts of diversity loss on the functioning of more natural ecosystems. - Net effects of biodiversity on ecosystem functions grow stronger as experiments run longer.

Over-yielding

- Enhances stability when mean biomass production increases with diversity more rapidly that its standard deviation.

Non-Economic Values

- Ethical - Species have an inherent right to exist. - Spiritual - Reflecting belief systems of particular religions - Aesthetic - Contributes to the quality of life even though no economic value can be placed on it.

enteric fermentation

- Fermentation that takes place in the digestive systems of ruminant animals, mammals that digest plant-based food by regurgitating semi-digested food and chewing it again.

Statement 2

- For many of the ecosystem services reviewed, the evidence for effects of biodiversity is mixed, and the contribution of biodiversity per se to the service is less well defined.

Statement 3

- For many services, there are insufficient data to evaluate the relationship between biodiversity and the service. - Some of this discrepancy may be attributable to different uses of the term biodiversity. - For example: we found little direct evidence that genetic diversity enhances the temporal stability of crop yield (as opposed to total yield); yet, most farmers and crop breeders recognize that genetic diversity provides the raw material for selection of desirable traits, and can facilitate rotations that minimize crop damage caused by pests, disease and the vagaries of weather. - This emphasizes the need for stronger and more explicit evidence to back up claims from biodiversity effects on ecosystem services.

Four Emerging Trends

- Four emerging trends that are changing the way we view the functional consequences of biodiversity loss.

Consensus Statement 6

- Functional traits of organisms have large impacts on the magnitude of ecosystem functions, which gives rise to a wide range of plausible impacts of extinction on ecosystem function. - Depending on the traits lost, scenarios of change vary from large reductions in ecological processes (for example: if the surviving life form is highly unproductive) to the opposite where the efficiency, productivity and stability of an ecosystem increases.

What happens when carbonic acid interacts with calcium carbonate?

- H2O3 + CaCO3 = Ca+ + XCO3 - In the presence of calcium carbonate - creates calcium ions - Calcium ions cause the exoskeletons made of calcium carbonate of certain organisms breakdown.

Habitat Loss

- Habitat is degraded and lost when natural or anthropogenic activities damage and destroy habitat to such an extent that it is no longer capable of supporting the species and ecological communities that naturally occur there. - It often results in the extinction of a species and, as a result the loss of biodiversity.

U.S. Corn Yields

- Has a cost on our environment - Deforestation - Fewer natural plants - less plants to absorb and fix atmospheric CO2

6th mass extinction

- Holocene - Currently occuring - Caused by humans - Loss of biodiversity

Fish Capture and Aquaculture

- Increase in farming marine organisms!

Carbon Sequestration

- Increase the amount of the carbon in the ocean - More carbon is absorbed and retained in the ocean

Factors in Overall Increase in Food Production

- Increasing area of cultivated land - Increasing efficiency of our yield per acre - Increased use of irrigation - Increased use of pesticides - getting rid of insects/pests that reduce our yields - Increased use of fertilizer - Crop improvement - artificial selection - All of these elements have significantly increased yields in wheat, corn, soy, etc. production!

Salmon Farming

- Increasing dramatically in how much are being farmed! - Low cost system - put salmon in river, raise them with natural water flowing through containing nutrients - Low input - Contained/controlled on how much water is flowed!

Habitat Degradation

- Is the destruction or loss of quality of the resources and necessities of a population or ecosystem

Biodiversity

- Is the variety of life, including variation among genes, species and functional traits. It is often measured as: richness is a measure of the number of unique life forms; evenness is a measure of the equitability among life forms; and the heterogeneity is the dissimilarity of life forms.

Upwelling

- Is when ocean currents cycle and bring up nutrients from the bottom parts of the ocean to the surface - In the middle of the ocean, where there is no upwelling, nutrients sink down and do not get cycled back up to the surface.

What happens when carbonic acid is in the water?

- It holds onto protons and wants to give it off to something else!

Low Reproductive Rate

- K-strategists - Some species with a low reproductive rate will take a very long time to replenish; their habitat might degrade before the species can replenish themselves. - Islands - often are small - the only place that they live or only occur on these islands

Consensus Statement 5

- Loss of biodiversity across trophic levels has the potential to influence ecosystem functions even more strongly than diversity loss within trophic levels. - Much work has shown that food web interactions are key mediators of ecosystem functioning, and that loss of higher consumers can cascade through a food web to influence plant biomass. - Loss of consumers can also alter vegetation structure, fire frequency, and even disease epidemics in a range of ecosystems!

Consequences of Biodiversity Loss

- Loss of ecosystem services! - Ecosystem collapse - "empty forests" - forests can no longer provide food for humans! - Biotic reactions cannot occur - Pollinator Decline - insect pollinators responsible for 75% of pollination for humans crops! - We are losing individuals in the species!

Cause and Effect of Deforestation

- Loss of natural resources - Food Insecurity - Loss of biodiversity - Global Warming

Emerging Trend 3

- Maintaining multiple ecosystem processes at multiple places and times requires higher levels of biodiversity than does a single process at a single place and time. - More biodiversity is required to maintain the "mutli-functionality" of ecosystems at multiple places and times.

Average U.S. protein intake

- Males - 102 grams - Females - 70 grams

Protein Sources

- Meat - Dairy - Fish - Legumes and other plant foods

Human Nutritional Needs: Quality Needs

- Must include the 9 essential amino acids that humans cannot synthesize

Human Nutritional Needs: Energy

- Need: Male - 2,500 kcal/day - Female - 2,000 kcal/day - Averages are influenced by age, activity, body size, metabolic rate.

How does undernourishment in certain countries occur?

- Not enough fertile soil means not enough plants will grow which means not enough food to feed animals which means humans do NOT get an efficient protein source!

Statistical Averaging

- Occurs when random variation in the population abundances of different species reduces the variability of aggregate ecosystem variables.

Shell Fishing Farms

- Only let in sea water when it is at the right pH - For example: Mollusks grow in cages- there is a constant flow of sea water going through these cages, the people working the farms will cut off the flow of sea water if they detect a change in the pH level of the water.

Fisheries

- Overall, many fisheries have decreased! - Many fish have been overharvested - Example: Atlantic Cod production since 1970 has significantly dropped off, pretty much gone in the 1990s. Atlantic Cod was over harvested - Fisheries declining in production are reflected in a number of other species due to overharvesting! - Example: Blue Fin Tuna

The Scientific Committee on Problems of the Environment (SCOPE)

- Produced an influential book reviewing the state of knowledge on biodiversity and ecosystem functioning (BEF).

Statement 1 - Provisioning Services

- Provisioning services 1. Intraspecific genetic diversity increases the yield of commercial crops 2. Tree species diversity enhances production of wood in plantations. 3. Plant species diversity in grasslands enhances the production of fodder 4. Increasing diversity of fish is associated with greater stability of fisheries yields.

Human Nutritional Needs: Protein

- Quantity Needs - 46-56 grams/day (U.S. government) - 40 grams/day (U.N.) for typical adults - Less influenced by activity than energy needs!

Economic Values of Biological Diversity

- Recreation - Food - Ecological Services - Scientific Research - Drugs/ medicine

A brief history

- Research suggested that loss of certain life forms could substantially alter the structure and functioning of whole ecosystems. - Organisms can influence the physical formation of habitats (ecosystem engineering), fluxes of elements in biogeochemical cycles, and the productivity of ecosystems (for example, via trophic cascades and keystone species).

Shrimp Farming

- Shrimp on the other hand is NOT a low input farming! - Habitat they require necessitates the the destruction of mangroves in order to raise them. - Mangrove - Is a type of coarse vegetation that serves as a natural buffer for erosion - from storms. - Farmers have concluded that these are the best areas to grow shrimp. - This process is quite costly! - Shrimp have to be fed "fish meal" - which is ground up fish parts - exceeds the amount of meat we get from shrimp. - 1 lb. of shrimp for every 5 lbs. of fish meal - Not efficient! - Increasing in the amount we are producing

Characteristics that make Species Susceptible to Extinction

- Some species have characteristics that make them more vulnerable to ecological and biological extinction. - These characteristics make survival harder when environmental conditions change or when humans interfere. - How narrow is their niche? - What resources do they depend on? - Specialization - Low reproductive rate - Example: California Candor - produced 1 young every two years! - Limited distribution, especially species living on small islands - geographic location are particularly susceptible to extinction

What causes extinction?

- Something in the environment has to change faster than a species can adapt!

Balance of Evidence - Statement 1

- Sufficient evidence that biodiversity per se either directly influences (Experimental evidence) or is strongly correlated with (observational evidence) certain provisioning and regulating services.

Emerging Trend 4

- The ecological consequences of biodiversity loss can be predicted from evolutionary history. - Species represent "packages" for all the genetic and trait variation that influences the efficiency and metabolism of an organism, and these differences are shaped by patterns of common ancestry. - Evolutionary processes generate trait variation among organisms are, in part, responsible for the ecosystem consequences of biodiversity loss.

Consensus Statement 3

- The impact of biodiversity on any single ecosystem process is nonlinear - change accelerates as biodiversity loss increases!

Emerging Trend 1

- The impacts of diversity loss on ecological processes might be sufficiently large to rival the impacts of many other global drivers of environmental change. - Although biodiversity has a significant impact on most ecosystems functions, there have been questions about whether these effects are large enough to rank among the major drivers of global change. - BEF relationship is NOT linear - the exact ranking of diversity relative to other drivers will depend on the magnitude of biodiversity loss, as well as the magnitudes of other environmental changes.

Rumen

- The rumen serves as their way of breaking down cellulose (grass/other plants) - indigestible material in plants - Rumen contains 200 different species of bacteria and other microorganisms, 20 of those can break down the cellulose - chemical reaction - We get methane CH4 - Methane is a greenhouse gas more potent (strong) than CO2 - CH4 can trap heat way more efficiently than CO2 in the forms of burps and flatulence - This is called "Enteric Fermentation" - Happens inside of the cow.

Consensus Statement 2

- There is mounting evidence that biodiversity increases the stability of ecosystem functions through time. - Five syntheses have summarized how diversity has an impact on variation of ecosystem functions through time, and these have shown that the total resource capture and biomass production are generally more stable in more diverse communities. - Mechanisms include - over-yielding, statistical averaging and compensatory dynamics.

Consensus Statement 1

- There is now unequivocal evidence that biodiversity loss reduces the efficiency by which ecological communities capture biologically essential resources, produce biomass, decompose and recycle biologically essential nutrients. - Reductions in the # of genes, species and functional groups of organisms reduce the efficiency by which whole communities capture biologically essential resources (nutrients, water, light, prey), and convert those resources into biomass. - Biodiversity effects consistent among different types of organisms - this consistency indicates that there are general underlying principles that dictate how the organization of communities influences the functioning of ecosystems.

Genetic Contamination

- These fish are DOMESTICATED - bred to be raised quickly - they are artificially selected - not similar to their wild counterparts!

Side Effects of Fish Aquaculture

- They can affect their wild neighbors on the other side of the net! - Shrimp and salmon are grown in DENSE populations which makes their populations more susceptible to disease - if disease spreads through the net - other wild animals can catch those diseases from pathogens in the water!

How ocean acidification affects the shell fishing industry?

- This is an industry that relies on healthy organisms with calcium carbonate shells! - $740 million dollar industry - Sea scallops are 77% of shell fishing production - Shells become thinner and the death rates of these organisms rise - Working families in this industry move away because they are losing profit - demographics in certain areas where these fisheries are will change!

Overharvesting

- To harvest something excessively and especially to a harmful degree.

Agriculture and Food Production

- Trends in food production have increased in total the amount of food that is produced.

Observation

- Two decades ago, at the Earth's summit, the vast majority of the world's nations declared that human actions were dismantling the Earth's ecosystems, eliminating genes, species, and biological traits at an alarming rate. - This observation led to the question of HOW such loss of biological diversity will ALTER the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper!

Ocean Productivity

- Water in the oceans towards the poles (where the water is colder) and along the coasts are relatively productive - there are lots of nutrients in these waters! - Nutrients sustain healthy populations of marine organisms - We obtain most of our food from the oceans in these areas - Warm waters are LESS productive - this is because there is no upwelling occuring.

Food Production World Wide

- We are NOT seeing an overall increase in food production throughout the entire world! - Worldwide undernutrition problem - and in other countries there is an overnutrition problem! - Example: U.S. being #1 in overnutrition - There have been increases in Type 2 diabetes because of this - what you get when you eat too much!

Changes in Ocean Acidity

- We are adding more and more CO2 into the ocean - CO2 is sequestered or retained in the ocean.

Six Consensus Statements

- We conclude the balance of evidence that has accrued over the last two decades justifies the following statements about HOW biodiversity loss has an impact on the functioning of ecosystems.

20 Years of Research on BES (Continued)

- We focused our efforts on the provisioning and regulating services of ecosystems, as these are the services that biodiversity studies have most often measured, and that are most frequently related to ecosystem functions. - For papers with data, we categorized the diversity-service relationship as positive, negative, or nonsignificant according to the author's own statistical tests.

20 Years of Research on BES

- We have learned that (1) optimizing ecosystems for certain provisioning services, especially food, fibre and biofuel production, has greatly simplified their structure, composition and functioning across scales; (2) simplification has enhanced certain provisioning services, but reduced others, particularly regulating services; and (3) simplification has led to major losses of biodiversity.

Linking biodiversity to ecosystem services

- We reviewed >1,700 papers to summarize the balance of evidence linking biodiversity to the goods and services provided by ecosystems. - We collated lists of provisioning and regulating services that have been the focus of recent summaries. - When a data synthesis was not found, we completed our own summary of peer-reviewed articles and categorized the diversity-service relationship as positive, negative, or nonsignificant according to the author's own statistical tests.

Extinction

- When the last individual of a particular species dies - When the entire population of a species dwindles into isolated, non-genetically diverse groups, the species may be effectively extinct.

Islands are the hardest

- Why? - Particularly susceptible - Small isolated populations - Geographic isolation - Usually NO natural predators, so the species living on the islands are not adapted to respond to introduced predators, not used to selection pressures from predators! - Humans introduce these predators!

What happens when the pH of the ocean decreases or the acidity increases?

- pH decreases due to more protons in the water - The protons will suck onto the calcium ions - this causes the breakdown of many species' exoskeletons made of calcium carbonate! - Example Organism: Mollusks - young mollusks particularly vulnerable in this process! - All begins by the burning of fossil fuels like coal, oil and natural gas, which releases carbon dioxide into the atmosphere and then the ocean absorbs that CO2 like a sponge!

Statement 1 - Regulating Services

1. Increasing plant biodiversity increases resistance to invasion by exotic plants 2. Plant pathogens, such as fungal and viral infections, are less prevalent in more diverse communities 3. Plant species diversity increases above ground carbon sequestration through enhanced biomass production 4. Nutrient mineralization and soil organic matter increase with plant richness.

Marasmus

A disease of severe protein-calorie malnutrition during early infancy, in which growth stops, body tissues waste away, and the infant eventually dies.

Carbonic Acid

CO2 + H20 = H2CO3

Kwashiorkor

protein deficiency