人在環境中透過知覺（或稱感知）接收到各種環境訊息，特別是經由視覺所接收到的影像訊息，形成環境的印象，同時產生心理認知、引發情緒體驗和生理反應。本研究目的在探討不同樹形對人的心理影響，發現不同樹形給人的情緒體驗不同，且在不同觀賞距離時，受測者對於各種樹形的心理體驗反應有顯著差異，例如在近距離，傘形樹明顯給人偏向「軟」而「暖」面向的體驗感；冠形、圓塔、橢圓和錐形樹的體驗感多落於「硬」的面向；棕櫚樹的體驗感多落於「冷」的面向。而同一種樹形在不同觀賞距離時，受測者的心理體驗有所改變，甚至有反方向的體驗改變。例如在觀賞距離至100公尺（含）以上，受測者對傘形樹心理體驗皆出現轉向，由暖、軟轉向冷、硬的體驗。棕櫚樹給人的雄偉感，隨觀賞距離增加而降低。圓塔形的莊嚴感也隨著距離增加而降低。在樹形偏好方面，近距離時受測者較喜歡傘形、卵形、圓形和冠形樹，較不喜歡錐形、圓塔形和橢圓形樹。而隨著觀賞距離增加，對傘形、圓形、棕櫚、橢圓形樹的喜歡程度降低。此結果可應用在環境設計上，例如老人社區可多配置有活力、生動、容易親近的圓形、傘形、卵形樹；在運動場地可多配置有活力、生動或具刺激感的圓形、傘形、卵形、垂枝形樹；在醫院可配置具有活力、可愛又有平靜感的圓形樹；有病懨懨感的橢圓、圓塔、垂枝、棕櫚形樹的應用則要慎重。

Humans rely on perception to receive various signals from their surrounding environment. In particular, images received through visual perception form environmental impressions that simultaneously facilitate psychological cognition and produce emotional experiences and physical reactions. This study explored the psychological effects of different tree forms on a group of participants and found that different tree forms provide different emotional experiences. Moreover, the participants differed significantly in their psychological reactions to the tree forms at different viewing distances. At a close distance, umbrella-shaped trees strongly evoked impressions of softness and warmth in the participants; crown-shaped, tower-shaped, elliptical, and conical trees, an impression of hardness; and palm trees, an impression of coldness. Participants' psychological experience of the same tree form also changed with their viewing distance, in some cases undergoing a reversal. For example, at viewing distances of 100 meters and greater, participants' impression of the umbrella-shaped tree shifted from warmth to coldness and hardness. Similarly, their impression of grandeur for the palm tree, or of solemnity for the tower-shaped tree, decreased with an increase in viewing distance. Regarding tree form preferences, at a close viewing distance most participants favoured umbrella-shaped, oval, round, and crown-shaped trees, and disliked conical, tower-shaped, and elliptical trees; however, preference for umbrella-shaped, round, palm, and elliptical tree forms decreased with an increase in viewing distance. The study results are applicable to environmental design. For example, round, umbrella-shaped, and oval trees, which are lively, vivid, and approachable, can be placed in senior communities. The active, vivid, and exciting forms of round, umbrella-shaped, oval, and weeping trees can be used on athletic fields. Hospitals might adopt lively, charming, and serene round trees. However, elliptical, tower-shaped, weeping, and palm trees may evoke an impression of sickness, and should be used with caution.