冷濕之檜木林中土壤淋洗作用極為緩慢，上層土壤礦物成分氧化鐵還原為二價鐵成鐵灰色之洗出層（E 層），經淋洗至下方。洗出層之鐵離子經氧化、結膠在洗入層(B層)，形成薄膠層(Bsm)。
薄膠層緻密不透水，當然也影響到水的通透性。 堅實的層次結構，對於檜木的根部而言，形成穿透的障礙。同時檜木根系為淺根性，不易從更深的土層中獲取養分，也無法深入土層來強化支撐功能，致時有風倒發生。

The leaching effect in the cypress forest lead to the formation of placic horizon a thin layer in soil; this thin layer is dense and impermeable that affected the permeability. The roots of cypress are shallow-rooted so that cannot obtain nutrients from deeper soil layers, and is also unable to penetrate the soil to strengthen the support function causing wind-falls.

孑遺物種指在遠古時代就已經存在於地球，而現今仍殘存部分的族群。根據學術研究調查發現紅檜、臺灣扁柏、臺灣衫、臺灣檫樹、臺灣粗榧、雲葉、紅豆杉等都是冰河期孑遺珍寶。

Relict species are living fossils growing from ancient time till today. According to the research, the relict species in Taiwan includes Taiwan Yellow Cypress, Taiwan Red Cypress, Taiwania, Taiwan Sassafras, Taiwan plumyew, Bird-lime Tree, Taiwan Yew and so on.

一般而言，當海拔高度由低海拔逐漸增加至中海拔雲霧帶時，森林植群物種多樣有增加的趨勢，但海拔高度若繼續上升時，物種的多樣性反而下降。棲地的多樣性造就物種多樣性，也吸引動物至此覓食。

Living fossils from the Ice Age, the cypress of Taiwan, are primarily located in the "cloud forest belt", an area known for its biodiversity. The Papilio maraho, a rare species of endangered swallowtail butterfly, is one of the protected species which can be found here.

檜木林帶受地形及環境氣候因子的作用下，產生不同的生態環境，使植物有其適生的環境及社會。紅檜較臺灣扁柏有較強的耐濕性及耐貧脊性，常分布於潮濕峽谷之山腹、溪谷，而扁柏則常生長於急峻山腹及嶺線之處。
檜木林植物社會主要組成，在上層優勢種以臺灣扁柏、紅檜；中層優勢種為棲蘭山杜鵑(Rhododendron chilanshanense)、山櫻花(Prunus campanulata)、太平山櫻( Prunus matuurai )、臺灣檫樹(Sassafras randaiense)等；下層優勢種為深山野牡丹(Barthea barthei)、假柃木等；地被層一葉蘭(Pleione formosana)、玉山箭竹(Yushania niitakayamensis)等。