Šumarski List 9-10/2010

IZVORNI I ZNANSTVENI ČLANCI – ORIGINAL SCIENTIFIC PAPERS Šumarski list br. 9–10, CXXXIV (2010), 475-486 UDK 630* 114.6 + 411 (001) VARIATIONS OF CARABID BEETLE AND ANT ASSEMBLAGES, AND THEIR MORPHO-ECOLOGICAL TRAITS WITHIN NATURAL TEMPERATE FORESTS IN MEDVEDNICA NATURE PARK RAZLIKE U SASTAVU I MORFOLOŠKO-EKOLOŠKIM ZNAČAJKAMA MRAVA I TRČAKA U PRIRODNIM ŠUMAMA NA PODRUČJU PARKA PRIRODE MEDVEDNICA Lucija ŠERIĆ JELASKA1, Ana JEŠOVNIK1, Sven D. JELASKA2, Aljoša PIRNAT3, Mladen KUČINIĆ1, Paula DURBEŠIĆ1 SUMMARY: The aim of this study was to investigate responses of ant and carabid assemblages and their morpho-ecological traits to habitat differences within natural temperate forests in Medvednica Nature Park. To quantify habitat differences in examined areas, both structural heterogeneity of the vegetation and taxonomic diversity of plants were measured on six plots. Habitat complexity was quantified using four habitat characteristics within the site: tree canopy cover; shrub canopy cover; ground herbs and leaf litter cover. Ants and carabids were sampled using pitfall traps. Ant species richness and abundance, unlike carabid species richness were positively correlated with habitat complexity, especially with leaf litter cover on plots. The responses of insects morpho-ecological traits to habitat were recor- ded, with more large bodied carabids present in more complex site and higher abundance of opportunist ant species in more open sites with low complexity of vegetation. Higher dominance of certain carabid species at the lower plots then those on the top of the mountain, suggest competitive exclusion, confirming lower areas as more stable. Species adapted to colder climate, that inhabit higher elevations such as flightless forest specialist Cychrus caraboides and Cara- bus irregularis, and boreo-montane ant species Camponotus herculeanus, are less competent to colonize lower areas. Furthermore, they may not survive se- vere instability of their habitats, especially in a changing climate. Overall re- sults suggest that conservation issues need to be focused on preserving stability and structural complexity of forest habitat in summit areas of the mountain. Key words: biodiversity, vegetation structure, litter, altitude, nature conservation, forest habitat INTRODUCTION – Uvod Mountain landscapes usually offer steep gradients perature, precipitation, etc.), what is reflected in the for a wide range of environmental parameters (i.e. tem- adaptation and distribution of different types of orga- 1 Dr. sc.Lucija Šerić Jelaska, dipl. prof. Ana Ješovnik, nisms and ecological communities that occupy different prof. dr. sc. Mladen Kučinić, prof. dr. sc. Paula Durbešić, positions along these gradients (review in Hodkinson Division of Biology (*Group for Systematic Zoology & Entomo- 2005). Many of these environmental factors are multifa- logy), Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia, Phone: +385 1 4877711; ceted and interlinked in defining overall structural com- Fax: +385 1 4826260, e-mail: [email protected] plexity of insect habitats, which Hodkinson (2005) 2 Doc. dr. sc. Sven D. Jelaska, Division of Biology (*Group has found to decrease with increasing altitude. The latter for Terrestrial biodiversity), Faculty of Science, University affects not only the species richness but also the species of Zagreb, Marulićev trg 20, 10000 Zagreb, Croatia 3 Mr. sc. Aljoša Pirnat, Groharjeva 18, SI-1241 Kamnik, Slovenia composition of insect communities (Whittaker 1952 475 L. Šerić Jelaska, A. Ješovnik, S. D. Jelaska, A. Pirnat, M. Kučinić, P. Durbešić: VARIATIONS OF CARABID ... Šumarski list br. 9–10, CXXXIV (2010), 475-486 in Hodkinson 2005). The physical structure of the (Thiele 1977, Pearce and Venier 2006). The use environment, mediated by plant communities, can inf- of carabids morpho-ecological traits like wing morpho- luence the distribution and interactions of species (re- logy, body size or diet are recommended in the evalua- view in Lawton 1983). “Structural heterogeneity tion of habitat quality (Blake et al. 1994, Gutiérrez hypothesis” assumes that structurally complex habitats et al. 2004, Gobbi and Fontaneto 2008). Brose may provide more niches and environmental resources (2003a) found that large carabids, as more preferable for exploitation and thus increase species diversity, alt- prey because of their higher nutritive value and redu- hough empirical support for this relationship is biased ced foraging time required, prefer dense vegetation towards studies of vertebrates and habitats under anthro- plots as enemy-free spaces. According to Ander- pogenic influence (Te w s et al. 2004). Lassau and s e n et al. (2002), ant functional groups can be used as Hochuli (2004) and Lassau et al. (2005) showed indicators of habitat quality and forest health under dif- that habitat complexity in forests may affect the compo- ferent management (Stephens and Wagner 2006). sition of ant and beetles assemblages. Brose (2003b) Lassau and Hochuli (2004) suggested measure- showed that effects of habitat heterogeneity on ground ment of habitat complexity as a surrogate for the diver- beetle assemblages were positive on the micro- and sity of a range of arthropods including ants. Very often, meso-scale (0.25 and 500–1000 m2, respectively), and different taxonomic groups indicate certain areas as im- were not significant on a macro-scale (10 km2). portant for protection or nature conservation, showing In “taxonomic diversity hypothesis” plant taxonomic mutual positive correlations. Based on the existence of diversity is positively correlated with the diversity of these correlations, the use of “surrogate species groups” herbivore insects (Murdoch et al. 1972, Root 1973), for estimation of overall biodiversity has been reported and thus with predator diversity (Hunter and Price (Garson et al. 2002; Sætersdal et al. 2003); being 1992). The importance of floristic richness for the particularly useful where limited biodiversity data exist. ground beetle abundance was also reported by B a - Vascular plants have been reported by Sætersdal et guette (1993). al. (2003) as a good surrogate group, which also works Ants and ground beetles have been widely recom- for estimation of ground beetle diversity. Although, mended as environmental, ecological and biodiversity some habitat preferences are known for many species of indicators (e.g. Altegrim et al. 1997, Andersen ants and ground beetles, it is not always evident which 1997, Niemelä 2000, Szyszko et al. 2000, A n - environmental factors are the most responsible for spe- dersen et al. 2002, Antonova and Penev 2006, cies assemblage and distribution. Pearce and Venier 2006, Šerić Jelaska et al. The aim of this study was to analyze ants and cara- 2007, Šerić Jelaska and Durbešić 2009). They bid species richness and abundance, carabids body size respond well to natural and anthropogenic disturban- and ants functional groups, in different habitats within ces. Microhabitat characteristics, i.e. litter type, orga- natural temperate mature forests, and to test whether nic matter content, insolation, temperature fluctuation, higher habitat complexity and plant species richness are important for providing hunting, foraging niches support higher insect diversity along vertical gradient and for protection of beetles from predators, oviposi- in Mt. Medvednica. tioning, larval development, over wintering etc. MATERIAL AND METHODS – Materijal i metode Study Area – Područje istraživanja Mount Medvednica is part of the Croatian contine- Med vednica are constantly increasing (road construc- ntal karst, located north of Zagreb, the capital of Croatia. tion, recreation, ski trails, logging, etc.), mainly at its The great floristic diversity (Dobrović et al. 2006), upper elevations, changing the habitat quality. This can due to the mosaic structure of forest communities, geo- change structural complexity of forests, especially where graphical position and geological structure make this trees and shrubs form part of the natural landscape. area very interesting for biodiversity investigations. Surveyed forests are natural temperate ones on Dobrović et al. (2006) reported that the floristic rich- brown acid soil with silicate parent rocks (Basch ness and diversity of the mountain was higher than simi- 1995). For this investigation, six plots (50 x 50 m) were lar regions in Croatia and several European countries selected along the central profile of Mt. Medvednica (Italy, Austria, Slovakia, Poland and Serbia). For protec- across a vertical gradient on both slopes of the moun- tion of its valuable forest areas, the western part of Mt. tain (Figure 1). They were placed in mature stands of Medvednica (228 km2) was proclaimed a nature park by five different forest communities, that account for 78% the Nature Protection Act in 1981. The highest peak of of the total forest cover of the nature park: Querco–Ca- the mountain, named Sljeme, is placed 1035 m above sea staneetum sativae Ht. 1938, (plot 1); Luzulo–Fagetum level. Despite protection, anthropogenic pressures on sylvaticae Mausel 1937, (plot 2); Lamio orvale–Fage- 476 L. Šerić Jelaska, A. Ješovnik, S. D. Jelaska, A. Pirnat, M. Kučinić, P. Durbešić: VARIATIONS OF CARABID ... Šumarski list br. 9–10, CXXXIV (2010), 475-486 Figure 1 Position of the study area - Medvednica Nature Park (black polygon) and position of investigated plots in the Park Slika 1. Područje istraživanja i položaj istraživanih ploha na području Parka prirode Medvednica

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