Why are there SO MANY Salamanders in Appalachia?

Reflecting on my recent trip into the heart of the Appalachians, I can't help but wondering why there are more salamanders here than anywhere else in the world Pick up the poster here: https://store.nebula.tv/collections/atlas-pro/products/atlas-pro-extinct-butterfly-art-print Follow me on twitter/x @theatlaspro Sources / further reading https://biodiversitymapping.org/index.php/amphibians/ https://www.jstor.org/stable/1443655 https://www.smithsonianmag.com/smithsonian-institution/the-surprisingly-colorful-salamanders-of-appalachia-813148/ https://www.oriannesociety.org/science-of-scales/hunting-for-salamanders-in-the-southern-appalachians/?v=400b9db48e62 https://www.ncarboretum.org/event/salamander-diversity-of-the-southern-appalachians/ https://enst250.wordpress.com/how-the-mountains-got-their-jewels-the-evolution-of-salamanders-in-the-appalachian-mountains/ https://www.ncwildlife.org/Portals/0/Learning/documents/Pisgah/Common-Salamanders-of-Western-NC.pdf https://herpsofnc.org/red-salamander/ https://digital.tnconservationist.org/publication/?m=58294&i=564495&view=articleBrowser&article_id=3295357&ver=html5 https://highlandsbiological.org/biodiversity-of-highlands-2/ https://tnaqua.org/riverwatch/why-is-southern-appalachia-so-salamander-friendly/ https://eeb.utk.edu/studying-salamanders-in-southern-appalachia/ https://www.flickr.com/photos/briangratwicke/38451035082 https://news.mongabay.com/2018/12/essential-ubiquity-how-one-tiny-salamander-species-has-a-huge-impact/ https://www.srs.fs.usda.gov/pubs/ja/ja_pough001.pdf https://www.fs.usda.gov/research/treesearch/47190 https://www.researchgate.net/figure/Map-of-the-salamanders-species-distribution-in-the-EU-data-source-IUCN-Red-List_fig1_324840024 https://salamandersofchina.myspecies.info/ https://www.zsl.org/news-and-events/news/critically-endangered-chinese-giant-salamander-revealed-be-multiple-species https://academic.oup.com/evolinnean/article/3/1/kzae007/7690816 https://www.researchgate.net/figure/Smoothed-elevation-map-of-the-southern-Appalachian-region-with-the-stations-considered_fig2_259328610