According to the World Reference Base for Soil Resources (IUSS Working Group WRB, 2006), the differentiation of Acrisols and Alisols is based on the cation-exchange capacity of clay, which cannot be directly determined in the field, but needs expensive and time-consuming soil-chemical analyses. This is an unsatisfactory situation for pedologists, who urgently require a rapid field method to distinguish illuviation-type reference soil groups (Alisols, Acrisols, Luvisols, Lixisols).In this study, we tested the ability of gamma-ray spectrometry to separate major WRB reference soil groups in the field. The underlying hypothesis is that Alisols and Acrisols are distinguished by their clay mineral composition, which should be reflected by geochemistry and consequently gamma-ray radiation (i.e., K-containing illite vs. K-free kaolinite). Highly significant differences in their gamma-ray spectrum for K, Th, and U were found for limestone and its soils. Especially the K and Th signatures allowed a clear separation of Acrisols and Alisols. In general, the surface radiation was sufficient to separate these soils. Best results were revealed considering parent rock and the whole soil profile. This means by using a portable radiometer and a pH meter, all illuviation-type reference soil groups could be distinguished in this case. If applicable at other sites, this approach could enormously reduce expenditures for soil-chemical analysis needed to assist soil classification.

Izvleček UDK 591.542(94+739,9) Andreas Wessel, Petra Erbe & Hannelore Hoch: Vzorec in proces: Evolucija troglomorfnosti pri jamskih mrežekrilnih škržatkih iz Avstralije in Havajev Preliminarne ugotovitve (Insecta: Hemiptera: Fulgoromorpha: Cixiidae) Evolucija troglobiontov zajema tri značilne korake: kolonizacija jame s površinskim prednikom, razvoj troglomorfnosti ter podzemeljska speciacija. Študija podzemeljskih mrežekrilnih škržatkov je prispevala veliko k našemu razumevanju evolucije troglobiontov in hkrati predstavlja uporaben modelni sistem za testiranje različnih teoretičnih pristopov, ki so bili razviti v zadnjih letih. V tem pogledu so najobetavnejši tisti taksoni, ki so si sicer sorodni, toda pripadajo evolucijsko neodvisnim troglobiontskimi linijami, kot so npr. tisti na Kanarskih otokih, v državi queensland (Avstralija) in na havajskem arhipelagu. Bližje sorodne vrste se v jamah pogosto pojavijo v primerljivih ekoloških pogojih, vendar se razlikujejo v starosti. Za ugotavljanje dinamike trendov redukcijske evolucije (evolucija troglomorfizmov) teh taksonov in jamskih škržatkov na splošno, smo v prispevku uporabili ocene primerjalnih starosti za avstralske in havajske jamske škržatke. Ugotavljamo, da stopnja troglomorfnosti ni v korelaciji s starostjo jamskih linij. Zgolj morfološke spremembe pri organizmih se ne bi smele uporabljati za prikazovanje filogenetske starosti jamskih organizmov. Hipoteze, ki temeljijo na takšnih predpostavkah, bi morale biti preverejene v luči pričujočih ugotovitev. Ključne besede: prilagoditveni premik, prilagoditve na podzemlje, klimatski relikt, učinek osnovatelja, redukcijski evolucijski trendi, troglobiti, troglomorfizmi. AbstractUDC 591.542(94+739,9) Andreas Wessel, Petra Erbe & Hannelore Hoch: Pattern and process: Evolution of troglomorphy in the cave-planthoppers of Australia and Hawai'i -Preliminary observations (Insecta: Hemiptera: Fulgoromorpha: Cixiidae)The evolution of troglobites comprises three distinct problems: cave colonization by an epigean ancestor, the evolution of troglomorphies, and intra-cave speciation. The study of cave-dwelling planthoppers has contributed much to our understanding of troglobite evolution and provides useful model systems to test various aspects of the theoretic framework developed in recent years. Most promising in this respect are taxa with several closely related but independently evolved troglobiontic lineages, such as on the Canary Islands, in queensland/Australia and on the Hawaiian Archipelago. Closely related species often occur in caves with comparable ecological parameters yet differ in their age. Here we use comparative age estimates for Australian and Hawaiian cave cixiids to assess the dynamics of reductive evolutionary trends (evolution of troglomorphy) in these taxa and cave planthoppers in general. we show that the degree of troglomorphy is not correlated with the age of cave lineages. Morphological alteration may not be used to draw conclusions about the phylogenetic age of cave organisms, and hypotheses based on...

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