ENVS 202 lecture notes up to midterm
ENVS 202 lecture notes up to midterm
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Date Created: 04/25/14
ENVS 202 42514 647 PM Homework 1 is due April 18 Environmental Science vs Environmental Studies Science scientific questions lea to testable predictions Answers to these questions are subject to challenge and revision Quantification Tragedy of the commons and shifting baselines Scientists don39t always agree but good scientists will change their minds when confronted with evidence that opposes their thoughts Evolution and Ecology of Salmon Iron Gates Dam and Nemesis Effect reading o Diatoms are microscopic algae which have silica rich cell walls o Dinoflagellates are another kind of microscopic algae Some produce toxins that cause red tides Creates a harmful algal bloom red that affects the species in that area o Overall point of this article Non inear effect if you push a button and expect a response there may be a disastrous effect that occurs instead o Important variables of the article dam zooplankton jellyfish dead vegetation toxins etc ConceptCausal maps 0 In general how do zooplankton affect the abundance of fish Fish eat zooplankton so if there are more zooplankton then there will be more fish 0 How do we represent this graphically Zooplankton 9 fish o What affect do fish have on zooplankton The more fish the less zooplankton o How do we represent this Fish 9 zooplankton o So how do zooplankton and fish interact Zooplankton 9 Fish U 6 Vsef regulatingnegative feedback loop o diatoms and dinoflagellates Diatoms 9 Dinoflagellates n 6 positive feedback oop sef reinforcing D an increase in one leads to an increase in another or decrease ENVS 202 42514 647 PM What is a main goal of restoration To get back to some natural state What is natural Have to think about what we are restoring it back to Get benefits from a healthy ecosystem O 0 Clean water Healthy food Salmon Case Study Types of salmon O Chum dog salmon not the biggest arrive in July most widely distributed from CA British Columbia Pink humpies rapid life cycle 2years spend a short time in the rivers then go out to sea come back to spawn and die limited in size Coho silver the sport cars fast spend a lot of time in the upper and lower regions of the stream Chinook king from Alaska to Oregon different types of Chinook salmon Sockeye Kokanee red salmon live and spawn in lakes an streams not connected to the ocean Steehead rainbow trout can survive their spawning periods can spawn multiple times Diversity of habitats makes it difficult to restore salmon habitats Things that affect the salmon habitat sedimentation the ocean trees etc 0 There are a lot of factors outside of human control ENVS 202 42514 647 PM Evolutionary Significant Unit ESU A population of organisms that is considered distinct for purposes of conservation You can have different ESU s of coho salmon Chinook salmon etc Harvest Hatcheries Hydropower Habitat Humans Extra Where do pesticides come from Pesticides chemicals used to control pests weeds etc They come from o Lawns herbicides 0 Agriculture pesticides Who cares o Conservationists 0 Land owners 0 Everyone How do pesticides affect salmon Physiology fertilityreproductive success Lethal effects vs Sub Letha effects Direct effects 0 Getting ingested Indirectly o Comes up through the food web 0 Juvenile samon what they eat what eats them what type of habitat they need AA can all be affected by the pesticides bottom up effect 0 decrease in shading of the river increased temp of the water Fields that can help study this Toxicology Environmental chemistry Population biology Community ecology Landscape ecology Conservation ecology Environmental policy Historical analysis of salmon Comet and asteroid who killed the dinosaurs Plate tectonics geology Ice age Climate variability Where on the time scale do these go First life oldest fossils 4 billion years ago Free oxygen in the atmosphere 0 There wasn39t always oxygen in the atmosphere salmon neededit Bony fish evolve 400mya Salmon family evolves Cascade mountains form plate tectonics Bony fishes Teleosts one of the subgroups of bony fishes includes salmon perch pike catfish What sets Teleosts apart from other fish They have a more efficient respiratory system Very muscular Require a lot of oxygen Big fish that move a lot Salmonidae split from other Teleosts about 100 mya What characterizes the Salmonidae of today Anadromous spawn in fresh water but mature in oceans 12 mya there was a type of salmon that weighed about 400 lbs and reached 810 ft in length Evolution Did salmonids evolve from fresh or saltwater ancestors How could we figure this out 0 Look at eating habits and see if they have changed over time 0 Fossil record 0 Three kinds of evidence suggests salmon started in freshwater Earliest fossils are found in freshwater They reproduce in freshwater 2 Reproductive traits often change more slowly Closely related groups are freshwater fish What challenges would face fish moving between streams and oceans Moving between these two requires changes in o Osmoregulation salt balance 0 Body coloration 0 Behavior Why did they evolve to go between salt and freshwater 0 Between 25 8mya oceans became more cooler and more productive 0 There was richer food 0 Salmon that migrated became bigger How might being bigger be advantageous 2 Better able to move through rapids waterfalls etc 2 Bigger fish make more eggs 2 Can dig deeper nests spawning success What do we know about the geologic history of the PNW over the last 10 15mya Coastal mountain ranges cause changes in rivers Cascade mountains formed major change in river drainage patterns Interior lava flows in Columbia basin repeatedly changed river patterns By about 2mya Things looked like today 0 5 species of salmon found in PNW today diverged from a common ancestor Salmon summary There are 7 native species 2 trout 5 salmon Why is the number of different species not a sufficient measure of the true diversity of salmonids in the PNW o A lot of diversity exists within species Stream type Chinook Spend one or more years in freshwater before going to the ocean Undertake extensive ocean migrations Return to natal streams in spring or summer Ocean type Chinook Move out of the river very soon Don39t travel far offshore Return to natal streams prior to spawning Watershed councils volunteer organizations that develop and participate in community efforts to restore and protect watershed health water quality and native fish populations 0 The Long Tom watershed council is a volunteer group of citizens from diverse perspectives coming together to learn about the watershed and do what they can do to improve the water quality and habitat conditions ENVS 202 42514 647 PM Salmon in the pacific NW have been and still are important Culturally for many people in the PNW salmon were and are closely tied to ways of life food identity and culture Ecologically as indicator species salmon might tell us about the functioning of watersheds They may also function to add nutrients especially phosphorous to streams nitrogen of cycle Economically fish markets food What comes to mind when people are buying fish Toxins Parasites Tapeworm you cant get this from fish that have never been in freshwater like tuna but you can get that from salmon mercury So human health Beneficial things Fatty acids Wild vs farmed Sustainable There is a message that farmed fish is bad and we should eat wild fish Do we ask ourselves these questions about grains beans fruit Most all the vegetables fruit we eat we farm So it is interesting to wonder about why there might be different circumstances What is aquaculture Aquatic organisms being farmed o Intervention in the rearing process to enhance production 0 Ownership of cultivated stock Vs Capture Fisheries o Disadvantage of capture fisheries bycatch and waste 2 as much as 40 of total catch expensive and difficult depleted stocks of many fish see fish stocks pie chart between 1413 of fish are over exploited o Concerns about aquaculture Ecological consequences of obtaining food for the fish Intentional fattening might include food more rich in PCB s Fish sometimes fed a dye to color flesh Antibiotics sometimes used to control disease Parasites or disease might flourish and spread to wild populations sea lice video So will we give up eating fish Or should we think about what kinds of fish are being farmed Roughly 13 of fish come from aquaculture Some fish are more efficient in converting food to body tissue They are the same temp as their environment they don39t have to spend more energy getting warm poikilothermic Neutrally buoyant So if we farmed those we wouldn39t be using as many other resources What are Barramundi Large scaled silver fish Aka Alaskan sea bass giant perch Australian sea bass Native to northern Australia up to southeast Asia Live in fresh water saltwater and estuaries Have been recorded up to 4 feet long and weighing nearly 90 lbs What makes them attractive for aquaculture Tiny heads with broad meat yieding flanks Can convert plant material into fatty acids in their eggs for their young Tuna and carp video Tuna live in the ocean and eat other fish Tuna are top predators Carpperch are freshwater o Able to feed on vegetation Video notes Two Fish Bluefin tuna is highly prized Eating bottom feeders carp is the future of aquaculture In the last 50 years fish stocks have been depleted by 90 Since 1975 the eastern Atlantic Bluefin tuna reproducing tuna percentage has fallen by 75 Tuna ranchers fins fish in the wild and fatten them up in pens Countries break their fishing quotas every year by around 4050 on average Sustainable Agriculture What foods provide humans with most of our caloric intake 0 Plant species Decreasing use these plants are Wheat maize rice barely soybeans sugar cane sorghum potatoes oats sweet potatoes What do we need besides calories 0 Nitrogen proteins minerals etc Globally what limits humans diet 0 Lack of food What are some common problems of or in agriculture 0 We rely on one particular family of plants 0 They are annual plants 0 Plants photosynthesis and they need light water and carbon dioxide What else do they need to grow 0 1 What kinds of compounds are plants made of sugar cellulose fiber protein fatty acids fatsoils o 2 What kinds of chemicalselements make up these compounds C H O sugars N S proteins A lot of these nutrients come from the soil solution or soil organic matter and the atmosphere What is soil 0 Soil is what dirt was before it got on the floor stan cook 0 Soil is a natural resource Hans Jenny 0 Soil has major components mineral matter organic material Is most agriculture done in areas that are were 0 Deserts o Grasslands 6 correct 0 Or forests Why is organic matter important for soil 0 It holds water it holds air and gives off mineral nutrients when it decomposes o Serves as a stable reservoir of nitrogen and phosphorous 0 Good balancer of water retention and drainage What are some problems that threaten agricultural soils 0 Erosion subsidence salinization Erosion a lot of erosion is not visible When things are tilled it opens up the soil for erosion or water can make this happen 2 What is the best way to prevent erosion 0 Don39t till the soil perennial crops would reduce soil tillage place crop strips and barriers There was a reduction in erosion from 19822003 because of the government paying the companies for not tilling soil Salinization evaporation from the surface water draws salt to the surface What does Wes Jackson propose as one solution 0 Use of both herbicides and pesticides o Polyculture of perennial grains oilseeds and legumes If we could do this we would have more carbon in the soil be less susceptible to drought less need for nitrogen fertilization less need for fossil fuels use less need for tilling less reliance on fossil fuel for traction reduces erosion less weed growth which creates a reduced need for herbicides The Land Institute Purpose is to develop an agriculture that will save soil from being lost or poisoned while promoting a community of life that is prosperous ENVS 202 42514 647 PM QUIZ MONDAY Main points from readings Hw 1 exam questions Lecture notes Recap of Last Class Aquaculture Water farming Capture fishing vs aquaculture pros and cons Filling a need for food 0 It is a growing industry Better health because of the energy needed for capture fishing Agriculture Resources nutrients and soil 0 You have to feed the fish and it comes from other fish or corn etc Aquaculture is more efficient in terms of economics Food production on the plant is changingit needs to Need to go to perennials aquaculture etc A 5step plan to feed the world National Geographic What agriculture is doing now and how we can change it to help By 2050 we will have another billion people 35 increase 0 To feed all these people we have to double our crops 0 Because some of the developing countries are eating more meat and you have to feed the cows feed the fish so as people are being added to the world we need to double our food Agriculture takes up 386 of the ice free land on the earth 0 Pastureland and cropland What have we learned about biodiversity of Oncorhyncus in the PNW There are 7 native species 2 trout 5 salmon What pattern Stream type more common in N ocean type more common in S Why The ocean type migrate to the sea in 6 months Stability productivity of riverine environment where fry are reared they spend more time in the ocean in the south in the north the oceans may be harsher and the rivers bigger and more stable Residence time the avg time of ocean type 6 months vs stream type 12 years 0 Steady state vs dynamic system IO AS If inputoutput so AS0 Steady state means AS 0 Dynamic system things are always changing and AS0 o What examples from lectures or readings use residence time Shifting baselines need to know if the changes we are seeing today are significant or not Amount of pesticide what response we get depends on how long it stays in the system 0 EX Reservoirs IO AS What is residence time then and how does it relate to a reservoir The residence time here would be the average time a unit of something salmon remains in a reservoir Residence time tVF 2 Time days hours min etc 2 Volume ength 3 cubic meters cubic feet etc 2 Volume flux discharge or transport rate in volume per time mquot3s Discharge vs Stage 0 Another name for stage is gage height unite in length ft or m o Areadepthwidth 0 Discharge areaveocity Residence time example 0 Fern Ridge Reservoir tVF F5000 ft 3s cubic fts cfs V 110000 acre feet 1 acre 43560 ft 2 U 110000435601acre 48 billion ft 2 2 43 billion ft 35000cfs960000sec lday86400 sec111 days increase volume residence time will go up decrease volume residence time will go down 0 What implications might the concept of residence time have for the Iron Gates Dam issue we discussed Decreasing the amount of sediment put into the sea Low oxygen levels led to the production of the poisonous gas Black sea has a really long residence time 2 Stagnant lower layer 2 Water stays there for a long time 2 All the oxygen is being used up because of the long residence time 2 Maybe if we opened up the dam a little more then there would be better circulation o How is residence time related to concentrations of pollutants o Other residence time examples Time a toxic chemical stays in a lawn Time a salmon stays in a watershed or ocean Time a forest is replenished with new trees Remember tVF Ecosystem change and Ecosystem Health Healthy forests equal healthy communities Why do we care about ecosystem health It affects our health Affects our earth and our environment What is a disturbance or pest Is fire a disturbance Or people Fire is a disturbance as are people Humans can be a huge artificial disturbance What conditions do we restore to And how do we decide Restoration attempts to return a degraded damaged or destroyed ecosystem to its historic trajectory of development determine from reference historical or intact ecosystems Forest Health Kob reading He does not have a utilitarian perspective which is see the forest and try to figure out what we can get out of it Health is a very organism specific concept 0 Rather than a whole forest What is a forest 0 A dense growth of trees plants animals o Diverse community in which trees are the most conspicuous members What is a healthy forest 0 Have enough biotic resources trophic networks 0 Resilience o functional equilibrium between resource supply and demand o diversity of seral stages and stand structures not the monoculture of a cottonwood pantationwe need young trees older trees different trees 2 need this to deal with change 0 does this definition apply to other ecosystems YES What organisms are important to the functioning of forests Why Nematodes worms make up half the animal biomass important link at the lower level trophic environment Moss lichen adds nitrogen from the atmosphere Mycorrhizae fungus that live on tree roots critical for water and nutrient uptake Cyanide millipede eat dead leaves and organic matter that litters the forest floor They excrete it and that becomes food for the bacteria and it gets effectively decomposed What structural features are important Snags habitat for birds Talus loose rock that eventually becomes soil Wood in streams fish condos make habitat What processes are important Landslides provide sediment for our rivers helpful to salmon Fires Floods can build fish condos or move sediment 42514 647 PM Residence time I O delta S t VF residence time is in time 0 volume is in length cubed volume flux is in volume per time ecosystem change and health def of a healthy forest resiliency biodiversity diversity of seral stages functional equilibrium Taus rocks and minerals that become soil Processes that make natural environmental impacts Fires Floods LandsHdes Ecosystem services Benefits obtained from nature that are critical to human health and well being What are the four categories of ecosystem services they describe in the USDA article Regulating services 0 Flood control erosion control stream temperature control Supporting services 0 The basic ecological abilities of the ecosystem o How it builds soil 0 The ability of a forest to support local flora and fauna 0 Nutrient cycling Provisioning services 0 What we get from that ecosystem agricultural food water Culturalrecreational services 0 Having a clean river to canoe 0 Hiking in a nice forest What is biological diversity It can be measures on various levels o Genetic diversity Within a species o Species diversity Within communities o Communityecosystem diversity ENVS 202 42514 647 PM What did we learn about biodiversity last time It exits at various levels 0 Within species 0 At the species level 0 At the ecosystem level At species level two aspects of diversity 0 Species richness 0 Species evenness Simpson39s index and effective species number 0 ltltrecapped in Habitable Planet Unit 9 reading Ecosystem Fragmentation What do you predict would happen if these communities were fragmented o It alters the ecosystem Would it affect species richness evenness or effective number of species 0 Yes loss of species could also affect the unaltered parts of the forest Could we model this 0 Yes by fragmentation graphs satellite views nat geo graph from last class Will all species be equally affected by fragmentation o No but if a certain species is affected that could have a larger affect on the other species Keystone Species A species that has a disproportionate effect on its environment relative to its abundance Such species affect many other organisms in an ecosystem and help to determine the types and numbers of various other species in a community EX sea otter keystone species top predator 0 Eat sea urchins which eat kelp which are a habitat for many other species EX Eurasian beaver keystone species ecosystem engineer o Lived in the UK got extirpated removed altered the landscape because they used to help the flora and fauna within their habitat EX North American Elephants o Traveled across the continent and dispersed seeds that altered habitats to make it better for living EX Lobaria Oregana moss o Adds lichen fixes nitrogen EX cyanide Millipede EX mycorrhizae 0 Critical for water and nutrient uptake Indicator Species Organisms that by their presence abundance or chemical composition demonstrate some distinctive aspect of the character or quality of the environment EX Northern Spotted Owls 0 Eat northern flying squirrels which eat truffles which are spore bearing structures of mycorrhizal fungi 0 They may not be a keystone species because there were other predators that may fill in if spotted owls are gone EX Salmon 0 When making a case about water quality or water health it may be an indicator species Biodiversity means more than just number of species present Which species are lost FRAGMENTATION Which species are added INTRODUCTIONS And how those species interact with each other What about invasive species Alien species plants animals or other organisms that are introduced to a given area outside their original range and cause harm in their new home Because they have no natural enemies to limit their reproduction they usually spread rampantly Recognized as one of the leading threats to biodiversity and they put huge threats to agriculture forestry fisheries and other human enterprises as well as health Bullfrog video 0 They took advantage of some already decreasing native species because of habitat loss and warming temperatures 0 Climate change models suggest the PNW may see warmer wetter springs in the future This will benefit bullfrogs over the other frogs o What kinds of habitat modifications might favor or disfavor bullfrogs Drain ponds pump in cool water Which animals are on the national 10 most wanted list zebra mussel northern snakehead Asian carp Chinese mitten crab new Zealand mud snail rusty crayfish oriental weather fish feral swine or wild boar common snapping turtle 10 bullfrog 9 39 Squot3939gt quotquot Are invasive species ALWAYS bad 0 In some places biodiversity has increased because of invasive species 0 On small scales invasive species come in and eradicate the other species But in large areas invasive species could actually help
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