this is the preview video for chapter 31 on conserving Earth's biodiversity we'll begin with a definition of conservation biology and then think about why biodiversity is important we'll take a brief look at some of the major threats to biodiversity think about habitat protection and how it impacts biodiversity and finish up with um a look at sustainability and some ways that we can make choices that will really impact the future of the planet so what is conservation biology this is the scientific discipline that looks at preserving the Earth's biodiversity the total of all of the variety of life we have biodiversity is usually split into a couple different areas we can think about genetic di diversity so we've talked about this in other areas of the course before so thinking about all of the alals and all of the organisms in different populations of a species we can think about species diversity within a particular ecosystem so how many different organisms are um living there and interacting and then we can think about ecosystem diversity this is the number of um types of ecosystems we have in the biosphere of a particular region Why is biodiversity important so we'll start with some monetary reasons because that is often what drives people's rationals when they make choices about how to interact with the world so um ecosystem services in general are benefits that we get from ecosystems and um things that ecosystems can do for us are um provisioning so this is providing things like raw materials for building um food energy like hydroelectric power ecosystems um provide regulating services so they help uh regulate things that we count on being stable water purification uh erosion and flood control um climate regulation carbon storage um Pest Control pollination all of these things often happen behind the scenes but are really important um we can also think about cultural services so um these are things that humans use very directly uh to impact our uh culture so Recreation tourism mental and physical health all really important and then finally supporting services again these are a little bit behind the scenes but we count them working well photosynthesis having genetic diversity soil formation and nutrient cycling all really important and so um we'll talk briefly about the you know monetary value um when economists add this up it's something like $125 trillion dollar a year in benefits and we'll talk about how important it is that ecosystems function properly so will come back to Keystone species and the Damage that can be caused when um they're altered we'll think about some of the major threats to biodiversity and obviously the large one is extinction that's death of all of the members of a species um scientists estimate that at least 99.9% of all of the species that ever existed on the planet are now extinct and that's not surprising because we've gone through five mass extinction events on the planet before you can see them briefly outlined here we won't have to memorize them for our course but you should have it on your radar that a lot of scientists think we're now in the middle of our sixth mass extinction driven primarily by environmental change and so this can be things like um habitat destruction and increased competition among species and the reason they think that is because the current Extinction rates are about a thousand times higher than what we consider sort of like the normal background rates um that we can uh establish from the fossil record so human activities are really mucking around with Extinction on the planet right now when we think about individual species and how we classify them based on how um endangered they are um if you are technically an endangered species that means you are end danger of becoming extinct in all or much of the range of that species um if a species is threatened they are likely to be endangered in the near future and and we can also think about things like local Extinction which means a species is lost from a particular region um there might be other members other populations um elsewhere but it can still have really big impacts um if they're needed locally and then obviously um Global Extinction is if something is lost from all of the places where it typically um lived and so just to give you an idea um something like 133% of bird species and 22% of mammals are um currently threatened in uh internationally so we have a lot of species that are in danger right now we said one of the things that drives Extinction is habitat loss and usually this is when humans all are altering habitats one of the things that's really common is called habitat fragmentation and so this is where a previously uniform habitat that was natural is carved out for lots of things that humans want to do with that land whether it's agriculture like you can see in this picture here Urban Development mining um pollution and so it's very different to have these little fragmented populations you can see some wooded areas still remaining here rather than um continuous areas that are adjacent to each other and so this is why um something like Mitchell Woods is so important we have um just under 20 acres there and so carving away at habitats really matters um when they become fragmented and isolated from each other and it's easy to think that any one um piece of uh things that humans are doing won't matter because there's wood or um resources elsewhere but it really matters to the animals who need large areas to survive we'll talk about the minimum viable population for a species as well and this varies on what the species is but this is um sort of like the Baseline number of organisms they need to have healthy reprodu ction and genetic diversity to be able to withstand threats so sometimes you might have a very small um fragment of habitat left and some organisms can live there temporarily but it might not be enough to sustain them over the long term we'll also mention something called overexploitation and this is when we're harvesting wild organisms at a pace that can't be maintained over the long term because that population just can't um reproduce quick quickly enough to catch up with the demand um because we are in New England at Mitchell College one of the classic examples is cod and so um we used to harvest um Cod at extraordinarily High rates here's a picture from the late 1800s and we'll talk about the devastating impacts that's had on the Cod populations and how they are at a point right now where they are having a tough time rebounding so species that have restricted habitat cats or um they have low growth rates have often have a tough time catching up when they've been overh harvested we'll also talk about invasive species um there are quite a few examples in Mitchell Woods we've talked about um Japanese knotweed and mugw right next to the pond we talked about multifloral Rose Barberry um some other examples as well this is typically when humans are moving plants or animals or insects from their native locations to new places where they don't have competition and especially if they have a high growth rate they can very quickly outcompete some of the Native species we'll also talk about pollution as a threat to biodiversity so the big classes are going to be synthetic chemicals so um things that we are commonly using to enhance our products so whether that's something like a pesticide or a flame retardant that we put in our Fabric and clothing or um a to make our clothing um water resistant or stain resistant or something we put in plastic like BPA to make it especially um durable and moldable um we'll talk about some uh recent studies that have come out with different types of chemicals um including um pfaas and how widespread we're realizing they are and how we're realizing it's starting to actually creep into um local Wildlife populations like you can see in this health advisory um from Michigan advertising not to eat the deer in a particular area because they have such high levels of some of these chemicals we'll also talk about toxic Metals so things like Mercury and lead and um and what you can actually do uh we'll talk about a classic example um with Rachel Carson in Silent Spring in the 1960s how she brought attention to the biomagnification of DDT in birds and how the United States actually put a band on DDT and how Wildlife recovered since then we'll also mention what can happen with high levels of nutrients so things like phosphorus and nitrogen running off from Farm Fields causing alil blooms and dead zones in our waterways all of this comes black to climate change because climate change can magnify all of these other effects that are happening so things like habitat and overexploitation of species are just Amplified when we have a environment that is potentially hotter with more extreme storms and lots of other changes that are happening um in our ecosystems right now when we think about habitat fragmentation we'll mention one of the things that we can actually do to help uh reduce the impact and that's making things like Wildlife corridors so here's an example of a highway that is connected by this over repass that Wildlife can actually use to get to two different areas that were previously fragmented by this highway running right down obviously if you're an animal this is very dangerous to cross and so things like Wildlife quarters that are purposely built in can help reduce not eliminate but at least reduce some of the impact of fragmentation when we thinking about the last chapter we'll be looking at uh sustainability heading into the future and so obviously there are lots of moral and philosophical reasons to care about the loss of biodiversity including um some very practical reasons um when we talked about all of those ecosystem services and so what does sustainable development look like this is like meeting the needs of the present without compromising the ability of future generations to also have their needs met so it's not saying no development at all but you just have to do it thoughtfully so living within your environmental limits and um you know trying to make sure you are building on renewable resources a lot of the land that is used by humans is used for agriculture so practices that farmers choose can have really big impacts and thankfully there is a lot of um interest right now in sustainable agriculture and so we'll talk about some different things that farmers are doing um both to control um soil erosion think about different ways of pest control fertilizer use how they irrigate um the types of crops they choose to grow crop diversity how they use fossil fuels um the quality of the water that's leaving their land um practices like not tilling their soil all of these are really going to make a big difference again because agriculture uses so much land we'll finish up the chapter thinking about um how we can make sustainable choices going into the future so we'll talk about ways um that we can conserve energy with our Heating and Cooling and our lighting our appliances our transportation how we can conserve materials thinking about um Recycling and reusing products how to conserve water how to minimize some of those um chemicals that we mentioned earlier um sustainable practices um thinking about things like food choices or the type of clothing um we choose to purchase and finally how the impact of anyone individual can be magnified through things like volunteering um educating making our vote making our vote count and I'm supporting uh organized conservation efforts okay that is it for the preview of chapter 31