Leaf Colors in the subalpine Zone

After a site representative for the vegetation of the respective elevational level was identified, a GPS point was sampled with a GARMIN handheld GPS device. Taking this point as a reference, three main transects of 20 m where laid out, one from North to South, the other from Northwest to Southeast and the third from Northeast to Southwest. These were marked with measuring tape, whereby the north facing end of the transect always represented the beginning, therefore zero, of the respective transects, building up a hexagonal plot design. Hexagonal plots have proofed to be excellent sampling units to assess diversity.
For each hexagonal plot, basic information regarding the sampling site, such as signs of herbivory and furthermore comments on the location were noted. Along each line transect, plant community information, such as species-specific cover, species-specific leaf coloration and leaf morphology characteristics (presence/absence of hairs, leaf area), were recorded. Additionally, the average growth height of each individual was estimated with a folding meter stick.
To assess the species-specific cover, a variant of the line intercept method was applied, which is optimal suited for cover estimations in shrublands and forests. For this method, it is necessary to define an underlying macroplot, in my case the hexagonal shape with the randomly chosen GPS point at its center. Within one macroplot a beforehand defined number of transects are placed. In my case I decided on three transects as described already. Along each transect the cover is sampled in two steps: first by measuring the number of meters intercepted by each plant individual along the transect. Second, these distances are summed up for every species present so that cover is expressed as meters a species is intercepting along a 20 m line transect. Overlapping individuals are recorded separately. Additionally, I measured, for every individual encountered, the growth height with a customary measuring stick. To account for open soil the amount of bare soil/ bedrock was recorded in the same manner as plant cover.
As a next step, leaf morphological measures were taken. These included color estimations, leaf area measurements and the quantification of leaf surface characteristics.
To assess the color heterogeneity, species specific leaf coloration of every species encountered along each transect was measured according to the Munsell Color System, in this case the booklet for plant tissue was used. In detail, this meant sampling ten representative leaves of each species encountered in the underlying macroplot and measure their color. Ten measurements per species were taken to cover the whole spectrum of colors one species showed within one plot and to account for possible variations. Ten leaves of each species were also measured according to their length and width to be able to calculate the leaf area afterwards.
To account for the leaf surface characteristics, qualitative properties were noted as verbal comments and the amount of hairs on the leaf surface were rated in four categories (none- light- medium- heavy). The initial idea of counting and estimating the amount of hair present was in the field not feasible, as it would have been too inaccurate and time consuming. As intensive farming (grazing cattle) only ceased to exist at approximately 2000 m.a.s.l. and the highest vegetated spot encountered during this session of fieldwork was at c.a. 2800 m.a.s.l., the gradient represents a total of 869 altitudinal meters with the lowest plot at 2015 and the highest plot at 2884 m.a.s.l..