Simone Fattorini

Insect rarity, extinction and conservation in urban Rome (Italy): a 120-year-long study of tenebrionid beetles

Abstract.u2002 1.u2002Urbanisation is an obvious cause of insect extinction, but few studies have investigated insect species loss in urban areas, and the importance of urban environment in conservation biology is controversial.

Biotope prioritisation in the Central Apennines (Italy): species rarity and cross-taxon congruence

The conservation status of invertebrates is usually lesser known than that of vertebrates, and strategies to identify biotopes to preserve invertebrate diversity are typically based on a single surrogate taxon, or even on the use of vertebrates as surrogates. Aim of this research is to illustrate a method for biotope prioritisation that can be easily adapted to different animal groups and geographical contexts. A two-step protocol for biotope prioritisation is proposed on the basis of a multidimensional characterisation of species vulnerability. Firstly, species vulnerability is estimated from rarity measures which include geographical range, abundance and biotope specialisation. Then, these values of vulnerability are used to rank biotopes. The method was applied here to the tenebrionid beetles, the butterflies, the birds and the mammals of the Central Apennines, a montane area of high conservation concern for South Europe. This study provides evidence for the importance of including insects in conservation decisions, because vertebrates are poor surrogates for insects. Conservation efforts in the reserves included in the study area are mostly focused on vertebrates, for which woodlands are considered particularly important. However high altitude open biotopes are crucial for both tenebrionids and butterflies, and preservation of such kind of biotopes would be beneficial also for vertebrates. The approach applied here demonstrates that (1) vertebrates are poor surrogates for insects, and (2) measures of species rarity, typically used in vertebrate conservation, can be obtained also for insects, for which a veritable amount of data are hidden in specialised literature and museum collections.

Use of insect rarity for biotope prioritisation: the tenebrionid beetles of the Central Apennines (Italy)

Insect conservation has been traditionally based mainly on the identification of priority biotopes. One of the most commonly used criteria for biotope prioritisation is the occurrence of priority species, hence the need for measures of species vulnerability. In this paper a two-step protocol for biotope prioritisation is proposed. Firstly, insect species vulnerability is estimated from rarity measures that can be easily derived from basic data. Then, these values of vulnerability are used to rank biotopes. The method was applied here to the tenebrionid beetles of the Central Apennines, a montane area of high conservation concern for South Europe. Their use in this paper is an example of the use of data hidden in museum collections for analyses dealing with traditionally overlooked insect groups. Most of conservation decisions for Mediterranean mountains are biased towards certain vertebrates. Although current management practices in the preserves of the study area are generally consistent with the conservation of tenebrionids (especially woodland protection, which is essential for arboreal species), results provided in this study stress the importance of preserving also open biotopes, which are crucial for many taxa, including several endemic forms. Moreover, there is indication that preservation of such kind of biotopes would be important also for vertebrates. The approach for biotope prioritisation based on species rarity was here applied to a single animal taxon, but it can be easily extended to other insect groups, in order to obtain a more general view of the relative importance of different biotope types for Apennine conservation.

Effects of fire on tenebrionid communities of a Pinus pinea plantation: a case study in a Mediterranean site

Fire is a frequent event in Mediterranean ecosystems, yet the effects on animal diversity are poorly understood. In this paper, the short-term effects of a severe fire on the tenebrionid beetles in a planted pinewood in Central Italy are investigated in comparison with those recorded in other animal communities, namely collembolans, isopods and birds. The use of statistical tests to compare values of dominance, diversity and equitability (measured with various indexes), between burned and unburned habitats, as well as the use of two major niche-based species abundance models (the geometric series and the MacArthur broken stick model), revealed a strong decrease in diversity and evenness in all investigated animal groups, including birds, for which previous research suggested minor effects. In particular, tenebrionids are proved to be particularly indicative of habitat transformations determined by fire, showing important changes in community structure, from that characteristic of woodlands to that of open habitats. Because most of the original vegetation of Mediterranean woodlands has been removed by the continued influence of man, mature pinewoods, even if artificial, represent an important surrogate habitat for most species of tenebrionids (and likely other animals of conservation concern, such as bird species), and their preservation from catastrophic fires is of paramount importance.

Disentangling the effects of available area, mid-domain constraints, and species environmental tolerance on the altitudinal distribution of tenebrionid beetles in a Mediterranean area

Most studies have attempted to identify the major environmental factors responsible for elevational variations in species richness. Such studies have been mainly performed in temperate and tropical areas, whereas the mediterranean biome has been substantially neglected. The aim of this paper was to disentangle the effects of available area, mid-domain constraints, and the environmental tolerance of species, on the altitudinal distribution of tenebrionid beetles in a Mediterranean region. A comprehensive faunistic database was used to assess the elevational distribution of tenebrionids in Latium (Central Italy). Variations in species richness, beta diversity and nestedness were analysed in association with variation in species ranges and midpoints. Variation in species richness was contrasted with patterns expected on the basis of the mid domain effect (MDE) and available surface area. After correcting for differences in area availability due to the conical shape of mountains, an unexpected triphasic pattern emerged: (1) at low altitudes, species richness was higher than expected on the basis of the effect of area and the MDE; (2) at around 800xa0m elevation, there is an abrupt change in species assemblages, and richness values fit those predicted by the MDE; (3) a new dramatic change occurred at 1,700xa0m, with tenebrionid assemblages composed of a small number of mainly eurytopic species. The integrated approach used in this study demonstrates that neither MDE nor monotonic patterns fully explain the observed diversity patterns. Variations in species ranges indicate that the elevational gradient filters species according to their ecological tolerance.

Should we correct rarity measures for body size to evaluate arthropod vulnerability? Insights from Mediterranean tenebrionid beetles

We investigated the influence of body size on rarity patterns at a regional scale using the tenebrionid beetles of Latium (Central Italy). For this we calculated geographical range size (no. of 10xa0km square cells), habitat breadth (no. of phytoclimatic units), and abundance (no. of sampled individuals) using a large database containing 3,561 georeferenced records for 84 native species. For each species, we used total body length to correct rarity measures for body size. Then we calculated vulnerability (Kattan) indices using both corrected and uncorrected rarity scores. Finally we used species range trends (expanded vs. contracted) as a measure of actual species decline. We found that range trends were correlated with vulnerability index independently from body size correction, the species with the highest vulnerability being those that experienced the strongest range contraction for both corrected and uncorrected measures. Also, we found that correcting for body size may be problematic because of the weak correlations between body size and geographical and ecological rarity (notably, abundance was not correlated). These findings indicate that correcting rarity for body size is not only theoretically questionable, but also practically difficult and possibly useless for conservation purposes.