Matching Pedodiversity and Biodiversity: Perspectives and shortcomings

Juan José Ibáñez (1), José Luis Rubio(2)and Pavel V. Krasilnikov(3)

(1) CCMA, CSIC, Madrid, Spain

(2) CIDE, CSIC, Valencia, Spain

(3) KarRC, RAS, Russia

Abstract

Biodiversity is one of the most popular items in the world environmental agenda. Pedodiversity begin to be a growing industry in the last years. Because a full inventory of biodiversity at taxonomic level is an amazing task, many ecologists and conservation biologists search biotic and abiotic surrogate indicators of taxonomic biodiversity. However, at the date matching biodiversity and pedodiversity have not paid attention between the experts involved neither pedodiversity nor biodiversity. Pedodiversity studies have merit by itself in order to preserving soils as part of our natural heritage (geodiversity). Furthermore, preserving pedodiversity in a natural state as possible (e.g. under natural undisturbed plant communities) permit selecting benchmark pedotaxa for soil quality monitoring studies, as well as, underground biodiversity conservation purposes. In fact the future EU Soil Protection Directive emphasizes the interest of preserving soil biodiversity as an essential component of the soil ecosystems. Thus, in first instance it is possible made use of pedodiversity tools in order to analyse the relationships between biotaxa and pedotaxa by one hand and biocenoses and soilscapes by other hand. However this novel pedometrics tools have also other perspectives and possibilities. To get these purposes it is needed to make some concepts clear.

  1. Currently pedodiversity studies shows that spatial soil patterns are very similar to those detected by ecologists in biodiversity studies. These are the cases, for example, of the termed taxa-area relations, increasing diversity along the time, the called nested subset structures, scale invariant structures (making use of fractal and multifractal formalisms) among others. Notice that this approach is different to matching biodiversity and pedodiversity taxa per taxa or soilscape per plant landscape. The former studies analyse the existing regularities in both spatial patterns with independence of a clear patching (correspondence one to one) among biological and pedological entities.
  2. Other different question is detecting the above mentioned correspondence between a given pedotaxa and a specific biotaxa (the same is true concerning to soilscapes and plant landscapes). Scientific sound interrelationships between both types of taxa could mean a more or less “deterministic” dependence of some biotaxa respect to certain pedotaxa. If it was the case, we should say that pedotaxa are the driving force of the plant assemblages and biodiversity composition in a given site. This fact only could occur in very idiosyncratic environments and sites. As soils and soilscapes, biological species and plant landscapes are the results of several environmental factors such as is indicated in the Jenny equation of soil forming factors. Thus we must expect that, in general pedodiversity is only a single determinant of species diversity, among others (climate, landforms, geology, history, man or natural perturbation, etc.).
  3. Both soils types and biological species are the product of taxonomies. However pedological taxonomiesare biased to agronomic purposes not for conservation ones. To this respect it is noticeable that biological and pedological classifications have different rationale but the same mathematical structure. If we try match pedodiversity and biodiversity it is necessary reorganise soil information contain in current pedotaxonomies in a way more rationale to plant ecology studies (e.g. similar and dissimilar soils from certain points of view). Probably this procedure must be done “ad hoc” in each different sites and environments.
  4. In contrast the relationships between soil biodiversity and pedodiversity have been none explored. However it could be an interesting novel research line. It is interesting have into account that soil organisms live into the soil and they must be affected by physical, chemical, etc., characteristics of each pedotaxa and its composition in terms of pedogenetic horizons. Thus, it is probable that in this case the matching could be better than with plant species.
  5. In any case current results of pedodiversity analysis could be very useful in conservation biology with independence of the above mentioned matching between pedotaxa and biotaxa. We will show as it is possible made use of soil maps and soil information for the design of natural reserves (mainly when in the region studied lack biodiversity information but there are soil maps; like is the case of many less developed countries) without previous studies of the matching between biotaxa and pedotaxa classes. The authors will show some examples.