This is what a giant Sequoia grove ravaged by wildfire looks like

so the area that we're standing in now which is on the sequoia national monument it's 100 mortality over story mortality there is no living foliage on any of these trees at all this must be what hell feels like when your whole world is burning can't go outside can't breathe and then the places that you love are burning to see trees that have lived to be that age and that size should not die in a wildfire that's not what they've evolved to do that's not what they're adapted to and so seeing something that just is so abnormal is hard i think for me to get my mind wrapped around somebody's got to tell this story you know because the sequoias are not going to speak for themselves [Music] what makes a sequoia it's it just is it's like that gestalt like it's like when when i was asking my dad if a ponderosa pine was a sequoia and he was like no you'll know it when you see it and it really is like when you see a sequoia you're like oh yeah that's what everyone's talking about these trees are sometimes called the guardians you know and you think back back in that time yeah they were but in the environment that they live in now they are no longer the guardians they're the victim [Music] [Music] i am lynnea hardland and i work for save the redwoods league as the giant sequoia forest fellow i'm also attending graduate school at uc berkeley in scott stevens lab and i am working on giant sequoia castle fire study for my master's research with alexis bernal my name is alexis bernal and i am a research assistant at the university of california berkeley stevens lab this summer looking at the effects of the castle fire on giant sequoia mortality well it's azi 204 okay so one of these in the fall of 2020 around this time last year we had a fire run through this area called the castle fire which burned through many of the giant sequoia groves it started as a lightning strike in a pretty remote area kind of over by the kern river canyon under certain weather conditions it kind of grew pretty rapidly and started burning through sequoia groves this year it was our plan to come in after the wildfire and do some post-fire monitoring so trying to get an assessment of not just what the overall tree mortality was in the fire footprint but specifically looking at how the old-growth giant sequoia fared during the wildfire [Music] this is one of our high severity plots as you can see it's 100 mortality in the overstory including a lot of the large sequoia that are around us and we're here kind of re-monumenting the plot to make sure that when we come back next year we know that we're re-measuring in the same place that we measured this year so that we can track that change over time more consistently we're also trying to look at management history so trying to get an assessment of what the forest structure and composition look like prior to the fire and whether or not that had an influence in the subsequent fire effects that way we can at least provide land managers with some sort of idea of ways at which they can treat their forest so that hopefully they can conserve these species in the future given that wildfire and climate change are obviously going to be an issue going forward cool either directly by the way that we've managed our forest or indirectly by the way we've affected our climate this is this is on us we did this people say well this is just the nature sorting itself out [Music] no humans have induced this problem sequoias are so highly fire adapted you know they require fire the radiant heat of fire to open their cones and drop their seed and then they require bare mineral soil for their cones to germinate but yeah so when it dries out like these spaces will open up and the seeds will fall out and so we know that they experience low moderate severity fire pretty frequently both from the scars but also just the fact that they have a really high height to live crown which is that like part of the stem or the bowl of the tree that's bare before you get to the live crown and so they don't often have a lot of live foliage that's close to the ground that would be able to catch on fire or allow fire to move up into the crown and they're thick bark and the fact that they require not direct heat but radiant heat to open their cones is really indicative of that low to moderate severity fire after over 100 years of fire exclusion and aggressive fire suppression through other things like grazing through over exploitative logging practices we've created these conditions that are really unhealthy for the forest right we have higher tree densities so these smaller sized trees that provide vertical continuity between the surface fire and the crown the tree canopy um and so that fire comes up travels up these ladder fuels gets into the crown as we have seen even into the crowns of these sequoias which historically right would resist that kind of fire because they're so high and then that fire is allowed to take off and propagate through that canopy much more easily than it would have there was a recent report put out by nate stevenson and christy bing from the national park service at sequoia kings canyon where they estimated based on aerial landsat imagery and they estimated about 10 to 14 percent of the world's giant sequoia population was lost in the castle fire alone [Music] sometimes when i stand here in front of them that's when it kind of like washes over me like wow this tree has been here through all of these historic events that have happened in the last 1200 years all of these weather events that have lasted and happened and during the last 1200 years and it still survived but now suddenly they're no longer surviving you know really in the blink of an eye on the time scale of the life of a giant sequoia it's gone [Music] i really don't know how to describe that feeling except for that it's just devastating um it's really important now to take a hard look at the groves that have been impacted by the castle fire because while it is depressing to see the things that have happened and they shouldn't have happened right now we have an opportunity to set these forests on a different trajectory than they're already heading that's what i want people to understand is we might have extreme topography we might have extreme weather but at the end of the day there is no fire without fuels so why aren't we manipulating the fuels to help prevent these sorts of things from happening you look at these trees that are left here and you can kind of see that this was a very dense forest of forest that needed fire just based on the size of the trees underneath the canopy of the monarch i cannot stress how urgent it is to really take action now because climate change is not gonna wait for us to catch up and our forests are already in such a compromised condition that they need a lot of work and so if we don't take action now i honestly think that this the consequence of that would be one of really humanity's biggest failures yeah i just hope that as californians we can be really proud of the fact that we saved this species that we become a state that's proud of a really robust prescribed burning program of a responsible ecologically minded forestry program here look at this one how big it is like compared to that one you know yeah it's got to be about 10 centimeters tall yeah and this one's just one year old and so most people walking by wouldn't even know that this is a giant sequoia despite its size um it is still a giant sequoia you know it came from this seedling or this this seed tiny little seed grows up to be one of the largest trees on earth these seedlings came from trees that died in the fire and so if this cohort doesn't survive then there will be no more sequoia in this part of this grove so this is essentially potentially the last generation of giant sequoia that will exist here unfortunately so i hope that it succeeds that's why we're coming back here and collecting this data to track seedlings like this over time and see how well they're doing but again that's kind of a very long-term process to determine that right we're gonna have to wait hundreds if not thousands of years to see if this ever becomes a monarch and it very well may or may not so it's definitely not going to be in our lifetimes yeah it's not it's something that we can you know work towards in our lifetimes yeah yeah we'll work the rest of our lives on this really and keep moving this work forward and really investing a lot of time and resources into protecting this protecting the seedling [Music] [Music] you

Channel: Scientific American

Views: 11,233

Keywords: science, nature, wildfire, fires, forests, climate change, global warming, foresty, california, giant sequoia, firefighting

Id: fzgzttNJYUE

Length: 12min 42sec (762 seconds)

Published: Wed Dec 15 2021

Reddit Comments

[u/LaKobe]

We’ve lost a lot more since the making of this film sadly

[u/twinxamot]

Damn. Here's the scientific report they mentioned: "Based on the three data sets with complete data, the estimated proportion of the Sierra Nevada’s large sequoias that died in the Castle Fire ranged from 10.49% to 13.67%. Rounding the lower value down and the higher value up, we estimate that 10 to 14% of all large sequoias in the natural sequoia groves of the Sierra Nevada died in the Castle Fire." https://www.nps.gov/seki/learn/upload/PreliminaryEstimatesSequoiaMortaliity_2020CastleFire_Draft-In-Press_508.pdf

[u/[deleted]]

God that is fucking sad. There's nothing in nature that I would like to see more than these trees.

[u/fencepost_ajm]

Keep in mind that this is about the old growth giant sequoias, it's not an extinction risk - there are smaller sequoia that are anywhere from saplings to decades to maybe a few hundred years old.

The tragedy is that once these thousand-year trees have died it's going to be thousands of years before groves get back to the same size.

[u/glassex]

10-14% loss of Sequoias is a significant number. I had no idea the fire was so bad. When they talked about these trees not regrowing within our lifetime, it made me wonder how many other fires like Castle Fire can the forest endure.

[u/jaspnlv]

Prescribed burns.

[u/WillzyxandOnandOn]

Also the same redwood which cones can propagate better post fires. These trees are adapted to seasonal fires. The fires lately seem to be much bigger and hotter than typical. Seasonal fires due to drought and in turn climate change/global warming. Losing the ancient ones is very sad and I think we should do everything to prevent that.

[u/GiantSequoiaTree]

Thanks for posting. Need more money put towards better protecting these old trees from wildfires as it's only going to get worse.

[u/SciTroll]

Whoa. That's crazy. I wonder how old some of those bigger trees were.