firstly proposed stress for medical term

defined the characteristics
→ a theory of stress (ストレス学説提唱), or general adaptation syndrome (汎適応症候群)

1. stressor (ストレッサー, ストレス刺激): external-environmental stimuli that induce stresses
   physical stressor: temperature, UV, etc.
   chemical stressor: chemical substance, enzyme, etc.
   biological stressor
2. stress (ストレス, ストレス反応): responses of plants (and animals) induced by stressors

[ water stress ]

→ habitat partitioning

Chilling injury (冷害)

Freezing injury (凍害)

these two injuries are closely related

Snow injury (雪害)

Relationships between broad-leaved trees and coldness

1. Direct effects: Ex. tissue fluid (water) frozen by low temperature → tissue(s) is(are) frozen → freezing injury
2. Indirect effects: Ex. frost drought (in particular the abovegroud organs)
   bark: vessels are clogged up → inhibition of water transportation + evaporation (on the aboveground) → death owing to dehydration

Difficulties in plant establishment in relation to cold tolerance

1. unstable climate in early fall
2. unstable climate in early spring (in particular occurring late frost)
   The frequency of late frosts determines the establihsment of European beech in Europe and Sakhalin fir in Hokkaido

seed dormancy