Unit 1: AP Environmental Science Faculty Lecture with Professor Jessica Hellman

Summary

Highlights

• Professor Hellman brings her Hoosier charm to a serious topic! 🌽🧑‍🔬
• The idea of emergence in ecosystems is like discovering a magic trick in biology! ✨
• Who would've thought butterflies and plants offer lessons in climate resilience? 🦋🌱
• Global biome patterns paint a beautiful yet changing picture due to climate. 🎨
• From boreal forests to your backyard—we all have a biome to protect! 🌳

Key Takeaways

• Ecosystems are complex systems with emergent phenomena that surprise us. 🌿
• Climate change is intricately linked with ecosystem changes, demanding urgent action. 🌍
• Understanding and preserving biomes are crucial for biodiversity and climate stability. 📊
• Professor Hellman emphasizes the need for sustainable energy transition. 🔄
• Adaptation to climate change is essential; everyone has a role to play! 👥

Overview

Chapters

• 00:00 - 03:00: Introduction and Personal Background Jessica Hellman introduces herself and expresses pleasure in speaking. The topic is the living world and ecosystems. In the 30-minute presentation, she aims to cover interesting and important aspects of ecosystems.
• 03:00 - 10:00: The Concept of Emergence in Ecology The chapter delves into the concept of complexity within ecosystems, particularly in the context of climate change. It discusses how the integrated and complex nature of ecosystems makes them unique among the different levels of biological study. The focus is on understanding the response of these complex systems to environmental changes, emphasizing the significance of emergent properties in ecology.
• 10:00 - 14:00: Emergent Phenomena and Biomes The chapter introduces the concept of emergence, explaining how complex systems exhibit patterns and processes that transcend the mere aggregation of individual system components.
• 15:00 - 19:00: Impact of Climate Change on Ecosystems The chapter discusses the implications of climate change on various species within biomes and ecosystems. It emphasizes the responsibility of humans in addressing these impacts. The speaker is a scientist and leader of an international research institution focused on cutting-edge research in this area.
• 20:00 - 23:00: Adaptation and Mitigation Strategies The chapter begins with the author's personal background, highlighting their unique connection to both rural and urban environments. Growing up half in Indiana, a state known for its agricultural roots, and half in the automotive heartland of metro Detroit, the author shares an illustrative photo taken by their mother during a bike ride on the Indiana farm. This dual heritage positions the author to appreciate and understand both the agricultural and industrial perspectives, which is essential when discussing the topic of environmental science with a focus on adaptation and mitigation strategies.

Unit 1: AP Environmental Science Faculty Lecture with Professor Jessica Hellman Transcription

• 00:00 - 00:30 hello hi there my name is jessica hellman and it is a great pleasure to be with you all today the topic that the college board asked me to speak on was the living world ecosystems so in the next 30 minutes i'm going to share just a tiny slice of what i think is particularly interesting and important concerning ecosystems specifically i'm going to organize my presentation
• 00:30 - 01:00 around the idea of complexity and i'm going to talk with you about how ecosystems in their complexity might respond to climate change and i'm taking this approach because ecosystems are the biggest and most complex of the various levels of biology that ecologists study so let's lean into their integrated parts and their big complexity so in my presentation today first i'm
• 01:00 - 01:30 going to tell you a little bit about me next i'm going to talk about this idea of emergence these are the patterns and processes that come out of complex systems that make them more than the sum of that system's individual parts then i'm going to talk about ecosystem patterns around the world called biomes these patterns arise from the fact that climate controls where the individual parts of an ecosystem the species that make it up where they can live on earth and then i'm going to talk about what
• 01:30 - 02:00 changing the climate implies for the species making up these biomes and ecosystems and what we as responsible human beings can do about it so let's get started first of all who am i well today i'm a scientist at a major research university and i lead an international research institution or institute working at the cutting edge
• 02:00 - 02:30 of environmental science but really i'm half farm cubed from indiana and other half child of the auto industry from metro detroit i say half and half because i moved from indiana to michigan when i was in the third grade just a photo my mom took bike riding on the farm in indiana my extended family are all hoosiers they're farmers or connected to agriculture and
• 02:30 - 03:00 from smaller towns my family my immediate family spent a lot of time outdoors and i learned from my the agricultural parts of my family to care about the stewardship of the land and natural resources that's how i got interested in nature my dad was also an engineer so math and science were a pretty big deal in my house so with that background in that experience i headed to college at the university of michigan which was my state's public university and from there i attended graduate
• 03:00 - 03:30 school at stanford university in northern california and it was in grad school that i learned to do field work and to study living things up close this is a photo that i took of two research assistants at my field site when i was in grad school we're in the native grassland of california just south and a little bit east of san jose and when i was in graduate school scientists were just beginning to wonder how climate change
• 03:30 - 04:00 might affect species and ecosystems and since then i have dedicated my entire career to that question how climate change might affect species and ecosystems so over the past 25 years i've figured out quite a bit about those effects and some things that we can do about it to mitigate those effects i'm really proud of those contributions of myself and my many colleagues who are making a difference both in science discovering new things about how species and
• 04:00 - 04:30 ecosystems work and also in conservation giving concrete ideas about what we can do to make the future better for living things and for us so one of the things that gets me most excited about ecology and ecosystems is the idea of emergence i was first introduced to this idea in college relatively late in college and it solidified for me that ecology was a cool thing so what is it an emergent phenomena is a
• 04:30 - 05:00 property displayed by a complex adaptive system okay that means it's any pattern or process that a complicated system displays that is more than the sum of its constituent parts because of complexity when many simple pieces come together a higher level function or pattern emerges and that function or pattern is because of the number and the interaction of the system's many parts
• 05:00 - 05:30 and sometimes it's hard to see the big pattern if you only look at the little individual parts so human consciousness is a classic example of emergence humans we sense all kinds of things in the world around us we process that sensory information and we even think and we make decisions about the world how do we do that we use our nervous system which is a complex system of interlinked neurons that transmit chemical signals
• 05:30 - 06:00 but consciousness is a much more complicated emergent phenomenon than a bunch of simple neurons linked together it's a pattern that results from many neurons interacting in complex ways now complex adaptive systems and their emergent phenomenon can have really surprising responses to change and manipulation when you perturb them and that's because their parts are interwoven and they affect one another
• 06:00 - 06:30 so i'd like to share an example with you of the complexity of interacting parts in a system and it concerns the bay checker spot butterfly so as a grad student way back when in that california grassland i showed you a moment ago i studied how this butterfly might respond to a warming climate if you think about the butterfly in isolation you might guess that warming could help it because butterflies rely on air
• 06:30 - 07:00 temperature to determine their body temperature so warmer temperatures could give could actually give butterflies more time to fly around and do the things that butterflies do but this butterfly is embedded in a complex system where it interacts with other species so when i warmed up the butterfly and the plants that it's larvae eat in the broader ecosystem i found that survivorship or the success or the number of the larvae through the
• 07:00 - 07:30 season depended on which host plant species they were eating especially when the conditions were warmer and you can see all of that in this graph so the squares on this graph refer to experimental plots where larvae are feeding but they only have access to one species of food it's the primary one that they tend to consume and it's the picture of it is in the top of this slide
• 07:30 - 08:00 the circles show the survivorship or number of larvae through time when they were able to feed on that main plant plus another less common host plant but this plant tends to last longer through the growing season especially when the temperature goes up and that secondary plant is on the bottom left of the slide so when the larvae had only the main plant they had survivorship over the growing season of this blue line but when they had both plants
• 08:00 - 08:30 were in a more complex system interacting with multiple species they had survivorship of the yellow line which is quite a bit higher and this is surprising because this stuff this study showed how warming affects the butterfly depends on the plants it has to eat within its ecosystem its interaction with other species turns out to be more important than the directive effects of warming on the butterfly itself and complex systems tend to be like this the interactions among the parts
• 08:30 - 09:00 species in this case can lead to surprising things that are hard to predict things you might not predict by just looking at the individual species themselves here's another quick example of emergence that i know you learned in the ap curriculum it's about trophic interactions you might remember and if you don't remember go back and look it up that ecosystems with three trophic levels can be very different from those with four trophic levels
• 09:00 - 09:30 because they have differing amounts of standing plant biomass so if you take this picture from marine ecosystems with and without killer whales the system with whales has less kelp than the system without whales because killer whales suppress sea otters and sea otters keep the sea urchin population in check and sea urchins eat kelp so again this trophic cascade another interesting fun
• 09:30 - 10:00 emergent phenomenon of ecosystems go back in check it out so next i want to share with you one of the coolest emergent phenomena i think in ecology and that's the dominant vegetation that appears around the entire globe and the fact that that vegetation is determined by relatively simple rules of climate the species involved are different in different locations but the basic patterns of the type of
• 10:00 - 10:30 vegetation showing up in different shows up in very regular ways all around the world and that happens because species have limits to where they live and the conditions they can tolerate and those conditions are strongly influenced by climate specifically by temperature and precipitation this graph shows those dominant forms of vegetation making up the world's major biomes again a function of average annual
• 10:30 - 11:00 temperature on the x-axis x-axis and annual precipitation on the y-axis and these different forms of vegetation have names like tropical forest or tundra or temperate forests and when you look on a map you can see the distribution of these vegetation types determined by the patterns of temperature and precipitation all around the world so near the equator for example where
• 11:00 - 11:30 it's hot and moist you find tropical forest at higher latitudes and higher elevations pointing to a few of them here in this slide you'll find cold and dry conditions and that corresponds to alpine grassland or tundra relatedly there are global patterns of species richness the number of species occurring in local ecosystems that the global patterns in species richness that are related to temperature
• 11:30 - 12:00 and precipitation too so the greatest number of species is found near the equator and tropical forest with decreasing number of species as you move closer to the poles it's the physiology that determines each species niche or the conditions that each species can tolerate and then interacting in ecosystems and the sum of all of those individual species that leads to these global patterns now i want to take a moment and share
• 12:00 - 12:30 with you my favorite biome this is a photo of a place in northern minnesota near the town of ely some of you might have heard about this place because it's considered the gateway to the boundary waters canoe wilderness a wonderful place to visit this is a place where land and water blend together with thousands of large and small lakes rich rivers and wetlands and the average temperature and precipitation in italy places it on
• 12:30 - 13:00 the boreal forest biome in fact that's what it looks like from decomposing material on the forest floor through the herbaceous understory to an overstory dominated with aspen birch spruce and pine i also list here some of my favorite species in this ecosystem from bears to sport fish to some really
• 13:00 - 13:30 cool mushrooms to wild rice which is a key cultural resource for native americans in the region and one of the most important things about boreal forests is that they store 30 to 40 percent of the carbon held in terrestrial ecosystems worldwide and most of that carbon is locked away in the soil because decomposition in these systems is relatively slow compared to primary productivity and that means that boreal forests are one of the most important sinks for
• 13:30 - 14:00 carbon worldwide another emergent property of a complex ecosystem okay so we need a break i want you to stop the video here in just a moment and i have an assignment for you i want you to go onto this website usclimatedata.com and look up your hometown or your favorite place i want you to take the average temperature calculate the average temperature it's
• 14:00 - 14:30 going to show you the mean average daytime high and the mean nighttime low you could just average those together to get the average overall and find the average precipitation for those of you that live in places where it snows you may need to take a snow number and convert 10 inches of snow into one inch of rain and then i want you to map that those values onto this biome graph just like i did for ely and i want to want you to find out what
• 14:30 - 15:00 biome you live in i also want you to take a few moments to make a list of some of the favorite species that live in that biome some of your favorite species that live in that biome what kinds of things are they what are the species that make that biome or ecosystem unique go do that come back i'll be here waiting
• 15:00 - 15:30 okay welcome back in the last part of my lecture i hope you discovered something interesting about the place that you live or you care about can give it a name and can recognize it as an emergent and interesting emergent ecosystem that contributes in some interesting way to the global patterns of biodiversity now in the last part of my lecture i want to talk about what happens to species and ecosystems when
• 15:30 - 16:00 the climate changes if climate is so important in determining ecosystem patterns around the world what happens when the climate changes first of all why is the climate changing the climate is changing because humans are manipulating the global carbon cycle something you also learned about we are unlocking carbon that had been removed from the active carbon cycle
• 16:00 - 16:30 where it was stored in rock and other deposits underground and we are re-releasing it into the active carbon cycle by adding it to the atmosphere in the form of co2 and ch4 carbon dioxide and methane and there are a few other greenhouse gases too but this addition of carbon to the atmosphere enhances the earth's greenhouse effect a natural greenhouse effect makes it more pronounced an enhanced greenhouse effect it enhances the ability of the
• 16:30 - 17:00 atmosphere to trap heat similar to how glass in a greenhouse traps heat and we do not know how much climate change will occur because we do not know how much fossil fuels humans are going to burn and when or if we'll ever stop it could be that we'll get lesser warming like shown on the left figure under lower emissions if we're lucky
• 17:00 - 17:30 or it could be that we'll get quite a lot of warming like the figure with higher emissions on the right we do know that a changing climate is a big deal for living things under a business as usual scenario with continued carbon emissions like the amount of warming on the right the earth would warm about six degrees celsius on average different amounts in different places but that average warming would happen within
• 17:30 - 18:00 less than a hundred years the last time that the earth was six degrees c cooler than today the same amount of difference opposite direction was during the last ice age and death valley a hot and dry desert in california that we know today was then under that cooler climate a mesic evergreen forest and the last time millions of years ago
• 18:00 - 18:30 that the atmosphere was similar to the co2 concentrations of modern climate change there were relatives of alligators living near the pools so in short six degrees celsius is a very different place when the climate was different in the past we had very different biomes too species that combined together to form ecosystems i want to consider north america i'll show you some data for north america
• 18:30 - 19:00 where scientists have used ancient pollen that's locked in sediments at the bottom of lakes you drill cores pull them up and you can count the pollen the species deposited at the bottom of that lake thousands of years ago and you can use that to reconstruct past composition of tree species in forest ecosystems if there was pollen at the bottom of the lake it means that that tree was in the neighborhood so at the peak of the last ice age boreal forests like the ones around
• 19:00 - 19:30 ely minnesota were pushed southward to this area shown in a circle here but beginning around 12 000 years ago as the ice started to retreat and the climate was warming some unique combinations of species that have no analog to modern times combinations that we wouldn't recognize today formed and they persisted for thousands of years that happened because species responded
• 19:30 - 20:00 individually to the changing climate while also interacting with one another now and as the climate became more similar to our modern climate through time the biomes that we recognize begin to take shape we do not yet know what climate change will do to the distribution and abundance of species globally and how those species combine into ecosystems around the world in the future we do know that factors
• 20:00 - 20:30 like how fast the climate changes and whether species can move and adjust to that change those things will have a big effect on the outcome undoubtedly some species won't be able to keep up or they won't be able to shift and they'll decline possibly even going extinct undoubtedly we will also see new no analog ecosystems species combinations that we don't have on earth today or haven't in the recent past
• 20:30 - 21:00 so what are we going to do about that about species decline about ecosystem change how can we protect ecosystems from the stress of a changing climate first we can stop climate change itself we know that we have already used up three-fourths of the human carbon budget releasing carbon into that active cycle carbon cycle we've already used up three-fourths of how much would be allowed if we want to avoid catastrophic climate
• 21:00 - 21:30 change we must also find a new way of living that relies on clean energy not fossil fuels and then uses that clean energy to power modern life but there's another thing we'll have to do we'll have to make adjustments to changing conditions something we call adaptation we will need to cool our cities irrigate our crops and protect our shorelines as the world warms if we're smart
• 21:30 - 22:00 we'll do that in a way that uses natural processes and ecosystems like in the pictures highlighted in yellow instead of relying on built unsustainable or artificial approaches so whether you go on to call study ecology in college or not we're going to need you society is going to need you to help
• 22:00 - 22:30 stop climate change but also to help adjust to climate to changing conditions and use your ecological and ecosystem knowledge to do so this is a profound challenge perhaps the largest humanity has ever confronted so we really need to get to work i hope you'll put your ap knowledge and experience toward that critical effort so that we can help build a future that has healthy ecosystems
• 22:30 - 23:00 for the benefit of other creatures but importantly for the benefit of humanity too thank you very much