"Toad back" and other things I learned at EGU on Teusday

The first of two soil crust-heavy sessions at EGU happened today. Overall, there were quite a few good presentations or posters. There were 2 in particular that really stuck with me:

1. Thomas Fischer talked about his method of measuring NDVI (Normalized Difference Vegetation Index) using images from a common digital camera. In addition to the RGB channels, he also takes paired images with and without an Infrared filter, so that he can actually approximate a 4 channel image. Multispectral imagery is very powerful (yet very expensive) for detecting a large number of phenomena including the development of biocrusts. One big problem is that the best possible spatial resolution that can be attained is a 25 cm pixel size. Fischer's approach enables image resulution in microns and makes image analysis affordable for a few hundred dollars.

2. Omarou Malam Issa presented a poster on a project led by Ambouta Karimou Jean-Marie documenting local knowledge of biocrusts in the Sahel region of Africa. The authors sampled the knowledge of people living along a latitudinal gradient of both sexes and belonging to either pastoralist or horticulturalist communities. The sampling spanned 5 different ethnic groups. Interestingly two different ethnic groups, speaking different languages, had converged on the name "toad back" for biocrusts due to it's dark bumpy appearance ("Bankwado" and "Korobanda"). Quite a few other references basically translated to either black soil or fertile soil. The majority of people surveyed clearly knew what biocrusts were. This is a really unique line of research which makes me curious about the native knowledge of biocrusts on North America.

New website featuring biological crusts

Dr. Maik Veste recently wrote me to let me know about his updated website on ecophysiology of biocrusts and dryland plants. It features photos from such disparate locations as Denmark, Germany, Israel and South Africa. There is also quite alot of content including papers, conference abstracts and a few posters. Find the website here.

Biocrusts on coastal dunes of Denmark. Photo: Veste, www.drylandresearch.de