Pieruschka Roland, Albrecht Hendrik, Muller Onno, Berry Joseph A, Klimov Denis, Kolber Zbigniew S, Malenovský Zbyněk, Rascher Uwe
1Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany Department of Global Ecology, Carnegie Institution of Washington, 260 Panama Street, Stanford, CA 94305, USA
1Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Tree Physiol. 2014 Jul;34(7):674-85. doi: 10.1093/treephys/tpu035. Epub 2014 Jun 12.
The photosynthesis of various species or even a single plant varies dramatically in time and space, creating great spatial heterogeneity within a plant canopy. Continuous and spatially explicit monitoring is, therefore, required to assess the dynamic response of plant photosynthesis to the changing environment. This is a very challenging task when using the existing portable field instrumentation. This paper reports on the application of a technique, laser-induced fluorescence transient (LIFT), developed for ground remote measurement of photosynthetic efficiency at a distance of up to 50 m. The LIFT technique was used to monitor the seasonal dynamics of selected leaf groups within inaccessible canopies of deciduous and evergreen tree species. Electron transport rates computed from LIFT measurements varied over the growth period between the different species studied. The LIFT canopy data and light-use efficiency measured under field conditions correlated reasonably well with the single-leaf pulse amplitude-modulated measurements of broadleaf species, but differed significantly in the case of conifer tree species. The LIFT method has proven to be applicable for a remote sensing assessment of photosynthetic parameters on a diurnal and seasonal scale; further investigation is, however, needed to evaluate the influence of complex heterogeneous canopy structures on LIFT-measured chlorophyll fluorescence parameters.
不同物种甚至单一植物的光合作用在时间和空间上都有显著差异，从而在植物冠层内产生很大的空间异质性。因此，需要进行连续且具有空间明确性的监测，以评估植物光合作用对不断变化的环境的动态响应。使用现有的便携式野外仪器时，这是一项极具挑战性的任务。本文报道了一种名为激光诱导荧光瞬态（LIFT）的技术的应用，该技术用于在距离高达50米的地面进行光合作用效率的遥感测量。LIFT技术用于监测落叶和常绿树种难以到达的冠层内选定叶组的季节动态。根据LIFT测量计算出的电子传递速率在不同研究物种的生长期间有所变化。LIFT冠层数据和在野外条件下测量的光利用效率与阔叶树种的单叶脉冲幅度调制测量结果有较好的相关性，但在针叶树种的情况下差异显著。LIFT方法已被证明适用于在昼夜和季节尺度上对光合参数进行遥感评估；然而，还需要进一步研究来评估复杂异质冠层结构对LIFT测量的叶绿素荧光参数的影响。
