Microclimatic conditions and plant morpho-physiological development within a tree shelter environment during establishment of Quercus ilex seedlings
Microclimatic conditions and plant morpho-physiological development within a tree shelter environment during establishment of Quercus ilex seedlings
复制标题
栎树冬青幼苗建立过程中树荫环境下的小气候条件和植物形态生理发育
DOI：
10.1016/j.agrformet.2007.01.012
复制
发表时间：
2007
影响因子：
6.2
通讯作者：
D. Jacobs
中科院分区：
文献类型：
--
作者：
J. Oliet;D. Jacobs
树木庇护所通常用于广泛的农业和林业应用，并且已知庇护所的存在通过影响小气候条件的庇护所-植物相互作用来影响植物发育。然而，树木庇护所的小气候发展相对缓慢的森林树种的特点，半干旱的地中海气候的影响还有待研究。在一个受控的环境下，使用mesic和旱生浇水制度，我们研究了小气候条件内的光和暗的树木庇护相对于非庇护条件和相应的影响，形态生理发育的霍尔姆栎（Quercus ilex L.）初建时的幼苗。尽管光合速率相对较低（<1μ molCO 2 m −2s−1），但遮蔽物内的CO2浓度在白天波动很大，反映了从下午晚些时候到晚上的呼吸作用和日出后最初2- 3小时的快速同化作用，中午前后急剧下降。在黑暗的庇护所内的中水分制度，减少蒸汽压赤字（VPD）与高植物蒸腾。较高的辐照度内光庇护所刺激光合作用，虽然较高的VPD在干旱条件下导致中午木质部水势降低光庇护所。此外，降低透光率之间的庇护处理（控制>光>暗）并不影响植物N或淀粉浓度，也没有总的植物生物量，但导致增加的高度，以及叶面积生产和地上部：根比在中温条件下，形态适应可能会增加干旱敏感性下炎热，干燥的条件下，该地区的夏末的特点。我们的结论是，树木庇护所内的小气候条件和相应的影响，植物形态生理发育是相互关联的，通过复杂的现象依赖于环境条件和表型特征的一个给定的植物物种。因此，住房配置必须适应气候条件的出植点与物种的可塑性，我们建议在地中海地区种植霍尔姆栎透光率高的光庇护所。
Tree shelters are used commonly under a wide range of agriculture and forestry applications, and the presence of the shelter is known to influence plant development through shelter–plant interactions that affect microclimatic conditions. However, effects of tree shelter microclimates on development of relatively slow-growing forest tree species characteristic of semi-arid Mediterranean climates have yet to be examined. Under a controlled environment using mesic and xeric watering regimes, we examined microclimatic conditions within light and dark tree shelters relative to non-sheltered conditions and corresponding influences on morpho-physiological development of holm oak (Quercus ilex L.) seedlings during initial establishment. Despite relatively low photosynthetic rates (<1μmolCO2m−2s−1), CO2concentrations within shelters oscillated widely during the day, reflecting respiration from late afternoon through night and rapid assimilation during the first 2–3h after sunrise that dropped sharply around noon. In dark shelters within the mesic watering regime, reduced vapor pressure deficit (VPD) was associated with high plant transpiration. Higher irradiance inside light shelters stimulated photosynthesis, although higher VPD under xeric conditions led to decreased mid-day xylem water potential within light shelters. Additionally, decreased light transmittance among shelter treatments (control>light>dark) did not affect plant N or starch concentrations nor total plant biomass, but resulted in increased height, as well as leaf area production and shoot:root ratio under mesic conditions, morphological adaptations likely to increase drought susceptibility under hot, dry conditions characteristic of late summer in this region. We conclude that microclimatic conditions within tree shelters and corresponding influences on plant morpho-physiological development are interrelated through complex phenomena dependent upon environmental conditions and phenotypic characteristics of a given plant species. Consequentially, shelter configurations must be adapted to match climatic conditions of the outplanting site with species plasticity; we recommend light shelters with high light transmittance for planting holm oak in Mediterranean areas.