Influence Of Temperature And Humidity On Photosynthetic Characteristics Of Four Colored-Leaf Landscape Plants

Photosynthetic characteristics indices (photosynthesis rate, transpiration rate, leaf stomatal conductance and internal CO₂) of four colored-leaf landscape plants (Cotinus coggygria'Purpureus', Cotinus coggygria, Sabina chinensis'Virens', Platycladus orientalis'Cervinus') in different air temperature and relative humidity were measured with CI-340 Photosynthesis system produced by CID corporation in America. This research analyzed influence of temperature and humidity on four colored-leaf landscape plants.The results showed that photosynthetic characteristics of four colored-leaf landscape plants significantly correlated with humidity and temperature, adaptation of photosynthetic characteristics to temperature and humidity was different and influence extent on photosynthetic characteristics of one plant differed.1) High temperature inhibited photosynthesis rate and transpiration rate of Cotinus coggygria'Purpureus', photosynthesis rate and leaf stomatal conductance of Cotinus coggygria, photosynthesis rate, leaf stomatal conductance and internal CO₂ of Sabina chinensis'Virens', leaf stomatal conductance and internal CO₂ of Platycladus orientalis'Cervinus'; promoted leaf stomatal conductance of Cotinus coggygria'Purpureus'.2) These, including internal CO₂ of Cotinus coggygria'Purpureus', transpiration rate and internal CO₂ of Cotinus coggygria, transpiration rate of Sabina chinensis'Virens'and photosynthesis rate and transpiration rate of Platycladus orientalis'Cervinus', were inhibited by high temperature and low temperature with suitable temperature about 30℃.3) High relative humidity inhibited photosynthesis rate, transpiration rate and internal CO₂ of Cotinus coggygria'Purpureus', photosynthesis rate, transpiration rate and leaf stomatal conductance of Sabina chinensis'Virens'and photosynthetic characteristics indices of Platycladus orientalis'Cervinus'; promoted leaf stomatal conductance of Cotinus coggygria'Purpureus'and photosynthetic characteristics indices of Cotinus coggygria. internal CO₂ of Sabina chinensis'Virens'were inhibited both by high humidity and low humidity with suitable humidity about 70%.Adaptation of two conifers was similar and so did two evergreen trees. Adaptation of two conifers differed from that of two evergreen trees because of distant genetic relationship.