Editing North Cascades National Park (section)

== Ecology ==
[[File:Thornton Lakes 25932.JPG|thumb|The Thornton Lakes fill glacier-carved basins near [[Mount Triumph]]|alt=Looking down into a valley below a high mountain on the right and a slightly smaller one on the right. In between are two lakes, one noticeably higher than the other. The lower reaches of the mountain and the area of the lakes have plant growth.]]
{{main|Ecology of the North Cascades}}
Eight distinctive life zones support thousands of different plant and animal species in the North Cascades National Park [[ecosystem]]. With an elevation gain of nearly {{convert|9000|ft|abbr=on}}, the park has one of the largest ranges of biodiversity found in any US national park.<ref>{{cite web|title=Nature|url=https://www.nps.gov/noca/learn/nature/index.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref><ref>{{cite web|title=Natural Features & Ecosystems|url=https://www.nps.gov/noca/learn/nature/naturalfeaturesandecosystems.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref>

===Flora===
The flora in North Cascades National Park is influenced by the great vertical relief, the amount of moisture an area receives, the slope and soil types as well as the [[fire ecology]]. This wide array of [[ecological niches]] has allowed a great biodiversity to evolve. Few other North American national parks have recorded as many [[vascular plant]] species as have been documented in North Cascades National Park. With 1,630 species documented, experts estimate adding [[non-vascular plant]]s and [[fungus|fungi]] could more than double the number of known plant species.<ref name="plants">{{cite web|title=Plants|url=https://www.nps.gov/noca/learn/nature/plants.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref> 
[[File:Arctostaphylos uva-ursi 25916.JPG|thumb|left|Common bearberry (''[[Arctostaphylos uva-ursi]]'') is a plant species normally found much further north but is found at higher elevations in the park.|alt=Reddish berries growing among thick, green, paddle-shaped leaves.]]
The park contains an estimated {{convert|236000|acre|km2}} of [[old-growth forest]]s.<ref name="1993OldGrowthEstimates">{{cite journal|last1=Bolsinger|first1=Charles L.|last2=Waddell|first2=Karen L.|year=1993|title=Area of old-growth forests in California, Oregon, and Washington|url=http://www.fs.fed.us/pnw/pubs/pnw_rb197.pdf|publisher=[[United States Forest Service]], Pacific Northwest Research Station|journal=Resource Bulletin|issue=197|id=PNW-RB-197}}</ref> As little of the park was previously logged, significant stands of old growth forest can be found in the valleys and lower slopes up to the timberline at {{convert|7000|ft|abbr=on}}. From the lowest valley floors to about {{convert|2000|ft|abbr=on}}, virgin stands of [[Tsuga heterophylla|western hemlock]], [[Thuja plicata|red cedar]] and [[Douglas fir]] are common. These species are heavily dependent on deep soils, and red cedars 1,000 years old and over {{convert|200|ft|abbr=on}} tall can be found on Big Beaver Creek.<ref name="lifezone">{{cite web|title=Life Zones|url=https://www.nps.gov/noca/learn/nature/life-zones.htm|publisher=National Park Service|access-date=March 23, 2018|date=August 11, 2017}}</ref><ref name="montane">{{cite web|title=Montane Forest|url=https://www.nps.gov/noca/learn/nature/bio-diversity3.htm|publisher=National Park Service|access-date=March 23, 2018|date=August 11, 2017}}</ref> These lowest elevation forests can be accessed by trails, such as the Happy Creek Forest Walk off State Route 20, the Shadows of the Sentinels at Baker Lake, Thunder Creek Trail at Diablo Lake and the Horseshoe Bend Trail from [[Washington State Route 542|State Route 542]].<ref name="lifezone"/> In openings in the forest canopy, [[Alnus rubra|red alder]] and [[Acer macrophyllum|bigleaf maple]] can be found but throughout this dense forest, ferns, shrubs and mosses abound.<ref name="montane"/>

Between {{convert|2000|and|5500|ft|abbr=on}} the forest is dominated by the [[Abies amabilis|pacific silver fir]] tree near State Route 20 at Rainy Pass. Also at this elevation, the western hemlock is replaced by the [[Tsuga mertensiana|mountain hemlock]] as a dominant species. At elevations between {{convert|4000|and|7000|ft|abbr=on}} in the [[subalpine]] zone, the forest gives way to meadows dominated by grasses and flowering plants and shrubs. Above {{convert|7000|ft|abbr=on}} lies the [[Alpine climate|alpine]] zone where few plant species survive aside from some sparse grasses, the occasional shrub and lichens.<ref name="montane"/><ref name="lifezone"/> A warming climate has led to an altitude adjustment for many flora species, with the timberline reaching {{convert|415|ft|abbr=on}} further up the mountain slopes since the 1960s.<ref name="brief">{{cite web|title=Climate Change Resource Brief|url=https://www.nps.gov/noca/learn/nature/climate-change-resource-brief.htm|publisher=National Park Service|access-date=March 29, 2018|date=January 30, 2018}}</ref>

The biodiversity of the area is threatened by climate change and invasive [[Introduced species|exotic plant]] species.<ref name="plants"/> These plants have spread across the park through the inadvertent redistribution from human activities, attaching themselves to cars and hikers. Invasive plants include the [[Centaurea diffusa|diffuse knapweed]] and [[Phalaris arundinacea|reed canary grass]].<ref name=invasive>{{cite web|title=Non-native plants|work=North Cascades National Park|publisher=National Park Service|access-date=June 6, 2012|url=http://www.nps.gov/noca/naturescience/non-native-plants.htm}}</ref> True grass species number nearly 150 in the park; half of those are considered exotic and nonnative to the ecosystem.<ref>{{cite web|title=Grasses|url=https://www.nps.gov/noca/learn/nature/grasses.htm|publisher=National Park Service|access-date=March 23, 2018|date=February 28, 2015}}</ref>

[[Pinus albicaulis|Whitebark pine]] is native to the park and grows at elevations over {{convert|5000|ft|abbr=on}} in the drier eastern region of the park.<ref name=whitebark>{{cite web|title=Whitebark Pine Resource Brief|url=https://science.nature.nps.gov/im/units/nccn/assets/docs/briefs/whitebarkpine_brief_20101129.pdf|publisher=National Park Service|access-date=June 28, 2018|archive-url=https://web.archive.org/web/20170219063730/https://science.nature.nps.gov/im/units/nccn/assets/docs/briefs/whitebarkpine_brief_20101129.pdf|archive-date=February 19, 2017|url-status=dead}}</ref> Whitebark pine is a stabilizing species for other species of high altitude flora and provides a food source for birds such as the [[Clark's nutcracker]] and mammals including [[Tamiasciurus hudsonicus|red]] and [[Douglas squirrel]]s.<ref name=whitebark/> Scientists believe that increasing temperatures will have a negative impact on the habitat necessary to support whitebark pine, and therefore impact a wide array of other species. [[Cronartium ribicola|White pine blister rust]] and [[mountain pine beetle]]s have devastated whitebark pine populations in many regions;<ref name="pine">{{cite web|title=Climate Science and Research|url=https://www.nps.gov/noca/learn/nature/climate_science.htm|publisher=National Park Service|access-date=March 29, 2018}}</ref> as of 2018, "28&nbsp;percent of whitebark pine trees are dead, 30&nbsp;percent are infected with blister rust, and 1&nbsp;percent have died from mountain pine beetles."<ref name="brief"/>

=== Fauna ===
[[File:Dendragapus fuliginosus 25865.JPG|thumb|Sooty grouse seen on the Thornton Lakes trail|alt=A neutral gray bird on the ground viewed through foliage.]]
This park has a diversity of animal species including 75 mammal species. A total of 18 species of [[carnivores]] including [[coyote]], [[bobcat]], [[Canada lynx|lynx]], [[North American cougar|cougar]], [[American mink|mink]], [[North American river otter|river otter]] and [[American black bear|black bear]] have been reported within this park.<ref name=mammalscheck>{{cite web|title=Species Checklist for North Cascades National Park (NOCA)|url=https://irma.nps.gov/NPSpecies/Reports/SpeciesList/Species%20Checklist/NOCA/1/false|publisher=National Park Service|access-date=June 29, 2018}}</ref> Several species of [[deer]] such as the [[elk]] and [[moose]], several more species of [[Bovidae|bovids]] including the [[mountain goat]] and [[bighorn sheep]], and more than two dozen species of [[rodent]]s like the [[beaver]], [[hoary marmot]] and [[American pika|pika]] are also present.<ref name=mammalscheck/><ref name="mammals">{{cite web|title=Mammals|url=https://www.nps.gov/noca/learn/nature/mammals.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref> Ten species of bats have been documented.<ref name=mammalscheck/> The [[Northwestern wolf|grey wolf]] is listed as an [[endangered species]], while the [[grizzly bear]] is listed as [[threatened species|threatened]].<ref name="endangered">{{cite web|title=Threatened, Endangered and Candidate Species Within the North Cascades Ecosystem|url=http://www.npshistory.com/publications/noca/threatened-endangered-species/treas4.htm#12|publisher=National Park Service|access-date=May 15, 2018}}</ref> North Cascade National Park has management plans in place to return grizzly bears to the park but not wolves, as the latter is seen as likely to reestablish themselves naturally over time.<ref>{{cite web|title=Wolf Status and Future|url=https://www.nps.gov/noca/learn/nature/wolf-status-and-future.htm|publisher=National Park Service|access-date=June 28, 2018}}</ref>

The park is a prime habitat for grizzly bear, but the species was extirpated from the region by 1860.<ref name=grizz>{{cite web|title=Grizzly Bears|url=https://www.nps.gov/noca/learn/nature/grizzly-bears.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref><ref>{{cite web|title=Wolverines and Climate Change|url=https://www.nps.gov/noca/blogs/wolverines-and-climate-change.htm|publisher=National Park Service|access-date=April 11, 2018}}</ref> Only two grizzly bear sightings occurred in the decade before 2015, and these were outside the park boundary in Canada.<ref name=grizz/> In 1991, a decision was reached by the Interagency Grizzly Bear Committee, a US Government land management agency committee, to make efforts to restore self-sustaining populations of grizzlies in the North Cascades region, which included the national park and surrounding national forests. In 1997, the North Cascades region was added to the National Grizzly Bear Recovery Plan; by 2017, the [[environmental impact statement]] for grizzly bear restoration was still in the public comment stage. Various action plans had been proposed to reestablish a self-sustaining population of 200 grizzlies in the region.<ref>{{cite web|title=Frequently Asked Questions: North Cascades Ecosystem Grizzly Bear Restoration Plan|url=https://www.nps.gov/noca/getinvolved/frequently-asked-questions-north-cascades-ecosystem-grizzly-bear-restoration-plan.htm|publisher=National Park Service|access-date=May 15, 2018|date=December 5, 2017}}</ref>

[[File:Mountain Goat North Cascades National Park.jpg|thumb|left|upright|Mountain goats have hooves that are well adapted to steep snow-covered slopes and cliffs|alt=An all-white goat looks at the camera. It has pale yellow irises and stands on snowy ground.]]
[[Wolverine]]s are one of the rarest and most elusive mammals in North America.<ref name=wolverinestudy>{{cite web|title=Wolverines|url=https://www.nps.gov/noca/learn/nature/upload/Wolverine-Resource-Brief-2012.pdf|publisher=National Park Service|access-date=May 15, 2018}}</ref> They are seldom sighted in the park, both due to the limited numbers of the species and the habitats they prefer, which are snowy high-altitude regions far removed from human encroachment. Approximately nine wolverines were captured in the national forest east of the park and fitted with transmitters that were tracked by [[Argos system|Argos satellite]] telemetry. Four of the wolverines frequented the southern sections of North Cascades National Park, and of those, two spent the majority of their time there; researchers were unable to determine if these study animals had reproduced in the park.<ref name=wolverinestudy/> A warming climate may impact any wolverine recovery efforts implemented due to the loss of snow cover this species needs to reproduce. Research indicates that wolverines den in deep snow at least {{convert|5|ft|abbr=on}} deep that lasts well into May, and as climate warms, these regions are becoming less common, especially in the lower 48 states.<ref name="brief"/>

More than 200 species of birds that pass through or use the park as a breeding ground have been recorded.<ref name=birds>{{cite web|title=Birds|url=https://www.nps.gov/noca/learn/nature/birds.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref> These bird species include both [[golden eagle|golden]] and [[bald eagle]] as well as [[northern spotted owl]], [[harlequin duck]], [[Clark's nutcracker]], [[trumpeter swan]] and seasonal appearances of [[western tanager]], [[Cassin's vireo]], [[pine grosbeak]], woodpeckers such as the [[pileated woodpecker]] and primarily ground-dwelling birds such as the [[sooty grouse]].<ref name=birds/><ref name="birdcheck">{{cite web|title=Species Checklist for North Cascades National Park (NOCA)|url=https://irma.nps.gov/NPSpecies/Reports/SpeciesList/Species%20Checklist/NOCA/2/false|publisher=National Park Service|access-date=March 22, 2018}}</ref> The [[peregrine falcon]] is the only species found in the park that is federally designated as an endangered species, while the [[marbled murrelet]] and northern spotted owl are listed as threatened.<ref name="endangered"/>

There are at least 28 species of fish documented, including all five species of Pacific salmon: [[pink salmon|pink]], [[chinook salmon|chinook]] (king), [[sockeye salmon|sockeye]], [[coho salmon|coho]] and [[chum salmon|chum]].<ref name="fish">{{cite web|title=Fish|url=https://www.nps.gov/noca/learn/nature/fish.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref> Various trout species including [[rainbow trout|rainbow]], [[lake trout|lake]] and [[brook trout]] can be found as can the [[largemouth bass]] and [[longnose dace]].<ref name="fishcheck">{{cite web|title=Species Checklist for North Cascades National Park (NOCA)|url=https://irma.nps.gov/NPSpecies/Reports/SpeciesList/Species%20Checklist/NOCA/3/false|publisher=National Park Service|access-date=March 22, 2018}}</ref>

Seven species of reptiles and about a dozen species of amphibians have been documented. Reptiles such as the [[northern alligator lizard]] and the [[common garter snake]] and amphibians such as the [[western toad]], [[Pacific giant salamander]] and [[rough-skinned newt]] reside in the park.<ref name=Holmes>{{cite web|first1=Ashley K.|last1=Rawhouser|first2=Ronald E.|last2=Holmes|first3=Reed S.|last3=Glesne|year=2009|url=http://science.nature.nps.gov/im/units/nccn/reports/inventory/NCCN_NOCA_Stream_Amphibian_Inventory_2005_20090215.pdf|title=A Survey of Stream Amphibian Species Composition and Distribution in the North Cascades National Park Service Complex, Washington State|url-status=dead|archive-url=https://web.archive.org/web/20111016094713/http://science.nature.nps.gov/im/units/nccn/reports/inventory/NCCN_NOCA_Stream_Amphibian_Inventory_2005_20090215.pdf|archive-date=October 16, 2011}}</ref><ref name="reptiles">{{cite web|title=Species Checklist for North Cascades National Park (NOCA)|url=https://irma.nps.gov/NPSpecies/Reports/SpeciesList/Species%20Checklist/NOCA/4/false|publisher=National Park Service|access-date=March 22, 2018}}</ref><ref name="amphibians">{{cite web|title=Amphibians|url=https://www.nps.gov/noca/learn/nature/amphibians.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref>

More than 500 species of insects have been recorded, including at least two dozen species of butterflies.<ref name=animals>{{cite web|title=Animals|url=https://www.nps.gov/noca/learn/nature/animals.htm|publisher=National Park Service|access-date=March 22, 2018}}</ref><ref>{{cite web|title=North Cascades National Park Service Complex: Butterflies in the Park|url=https://www.nps.gov/noca/learn/nature/upload/NOCA_Butterflies_NPSpecies_Report_20170109_comp.pdf|publisher=National Park Service|access-date=March 22, 2018|date=January 9, 2017}}</ref> Around 250 species of aquatic invertebrates can be found in the parks waterways.<ref>{{cite web|title=Species Checklist for North Cascades National Park (NOCA)|url=https://irma.nps.gov/NPSpecies/Reports/SpeciesList/Species%20Checklist/NOCA/7,9,6,8/false|publisher=National Park Service|access-date=March 22, 2018}}</ref><ref name=animals/>

=== Fire ===
[[File:Copper Mountain Lookout WA NPS.jpg|thumb|Copper Mountain Fire Lookout|alt=A white-painted wooden building. It has many windows which have wooden covers above them. In the background are mountains.]]
In North Cascades National Park, fire was used by Native Americans in the region near present-day Ross Lake to clear out brush, to ease foot travel, and possibly to flush animals out of the foliage.<ref name=apostol/> Evidence found in the patterns of tree growth as well as from tree ring analysis indicates human-caused fires were created for many hundreds of years. Similar evidence is found in the Stehekin Valley, where both smaller low intensity fires and larger fires are suggested by the growth patterns and burn scars in tree ring evidence. The low-intensity fires that were likely human induced were only found in the easternmost regions of the park. In the subalpine regions such as the Thunder Creek area, the studies concluded fire occurs at frequencies ranging from 30&nbsp;years to 400&nbsp;years.<ref name="fireplan">{{cite web|title=North Cascades National Park Service Complex Fire Management Plan|url=https://www.nps.gov/noca/learn/management/upload/fmp-wfdss-final-lockedsigned-5-25-10-dt.pdf|publisher=National Park Service|access-date=April 3, 2018|date=April 2010}}</ref>{{rp|8}}

Across the entire North Cascades National Park Service Complex, between 1973 and 2003, there were 113 human-caused fires that burned {{convert|106|acre|abbr=on}}, and 264 lightning-caused fires that burned {{convert|11672|acre|abbr=on}}.<ref name="fireplan"/>{{rp|13}} During this period, the largest fire consumed {{convert|4118|acre|abbr=on}}, mostly in Ross Lake National Recreation Area. North Cascades National Park Complex has three different zones with varying ratings for fire potential and severity.<ref name="fire">{{cite web|title=Fire Ecology in the North Cascades|url=http://www.npshistory.com/publications/noca/research-catalog/fire.htm|publisher=National Park Service|access-date=April 3, 2018}}</ref> The park is managed as the Skagit Fire Management Unit (FMU) and has a low frequency of large natural fires that occur on average only every 50 to 400&nbsp;years.<ref name="fireplan"/>{{rp|36}}

North Cascades National Park has a condition type that shows "...natural (historical) range of variability of vegetation characteristics; fuel composition; fire frequency, severity and pattern; and other associated disturbances."<ref name="fireplan"/>{{rp|22}} This condition type, in keeping with the wilderness designation applied to most of the park, equates to a natural "let it burn" policy overall, so long as people and historical property are not threatened and the fire was lightning-caused. As part of the management plan, the few historic structures in the FMU are prioritized for fire protection including backcountry shelters like [[Beaver Pass Shelter]], and [[Fire lookout tower|fire lookouts]] such as [[Sourdough Mountain Lookout|Sourdough]], [[Desolation Peak (Washington)|Desolation]] and [[Copper Mountain Fire Lookout|Copper lookout]], all of which are on the [[National Register of Historic Places]].<ref name="fireplan"/>{{rp|42}}