Plant trait data have been used in various studies related to ecosystem functioning, community ecology, and assessment of ecosystem services. Evidences are that plant scientists agree on a set of key plant traits, which are relatively easy to measure and have a stable and strong predictive response to ecosystem functions. However, the field measurements of plant trait data are still limited to small area, to a certain moment in time and to certain number of species only. Therefore, remote sensing (RS) offers potential to complement or even replace field measurements of some plant traits. It offers instantaneous spatially contiguous information, covers larger areas and in case of satellite observations profits from their revisit capacity. In this review, we first introduce RS concepts of light-vegetation interactions, RS instruments for vegetation studies, RS methods, and scaling between field and RS observations. Further we discuss in detail current achievements and challenges of optical RS for mapping of key plant traits. We concentrate our discussion on three categorical plant traits (plant growth and life forms, flammability properties and photosynthetic pathways and activity) and on five continuous plant traits (plant height, leaf phenology, leaf mass per area, nitrogen and phosphorous concentration or content). We review existing literature to determine the retrieval accuracy of the continuous plant traits. The relative estimation error using RS ranged between 10% and 45% of measured mean value, i.e. around 10% for plant height of tall canopies, 20% for plant height of short canopies, 15% for plant nitrogen, 25% for plant phosphorus content/concentration, and 45% for leaf mass per area estimates.The potential of RS to map plant traits is particularly high when traits are related to leaf biochemistry, photosynthetic processes and canopy structure. There are also other plant traits, i.e. leaf chlorophyll content, water content and leaf area index, which can be retrieved from optical RS well and can be of importance for plant scientists.We underline the need that future assessments of ecosystem functioning using RS should require comprehensive and integrated measurements of various plant traits together with leaf and canopy spectral properties. By doing so, the interplay between plant structural, physiological, biochemical, phenological and spectral properties can be better understood. Disciplines Medicine and Health Sciences | Social and Behavioral Sciences Publication DetailsHomolova, L., Malenovsky, Z., Clevers, J. G. P. W., Garcia-Santos, G. & Schaepman, M. E. (2013 ecology, and assessment of ecosystem services. Evidences are that plant scientists agree on a 22 set of key plant traits, which are relatively easy to measure and have a stable and strong 23 predictive response to ecosystem functions. However, the field measurements of plant trait 24 data are still limited to small area, to a certain moment in time and to certain number of 25 species only. Therefore, remote sensing (RS) offers potential...

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Abstract:Mixed tree-heath/beech forest is a type of subtropical montane cloud forest found on wind-and fog-exposed ridges in the Canary Islands. With a dry season of 5 months and an annual precipitation of 600-700 mm, the extra water inputs through fog interception assume particular importance in this environment. Measurements were made of rainfall, fog occurrence, wind speed and direction as well as of throughfall (TF) in a ridge top cloud forest located near the centre of the National Park of Garajonay on the island of La Gomera. Measured amounts of incident rainfall were corrected for wind-induced losses around the gauge and for topographic effects. Amounts of fog water as collected by a 0Ð25-m 2 fog screen were corrected for changes in effective screen surface collection area depending on wind direction. No such corrections were taken into account in most if not all previous studies of rainfall and fog water inputs in the Canary Islands. TF fractions differed between events with rain-only (87% of wind-corrected rainfall), fog-only (¾6% of wind-corrected fog) and mixed precipitation (110%). It is concluded that the fog screen was more efficient at capturing fog water than the forest canopy, whereas previous wetting of the canopy and bryophytes by rain may have caused the higher TF fraction found on days with rainfall and fog.

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