European Journal of Soil Biology 40 (2004) 47–53 www.elsevier.com/locate/ejsobi Original article Recolonization of a burnt pine forest (Pinus pinaster)by Carabidae (Coleoptera) M.M. Fernández Fernández a,*, J.M Salgado Costas b a Dpto. de C. Agroforestales, Area de Zoología, Universidad de Valladolid, E.T.S.I.I.A.A. Palencia, Avda Madrid 44, Palencia 34071, Spain b Dpto Biología Animal (Zoología), Fac. C. Biologicas y Ambientales, Univ. León, Spain Received 10 March 2003; accepted 8 January 2004 Abstract This paper describe changes in Carabid fauna after a wild fire in June 1996 in a Pinus pinaster forest in Spain, and also, provides information about trap selectivity and the influence of a firebreak on carabid abundance. Sampling was carried out from April to October 1997 in the burnt area and in a nearby unburnt pine forest. Pitfall traps contained three different types of attracting bait and were placed in each area at different distances from the firebreak. The colonizing species in the burnt area are described and compared to those captured in the control pine forest. Data on abundance, species richness, equitability, diversity and size differences are given. Seasonal changes and the composition of the Carabidae community after the fire are also discussed. Greater abundance was observed in the burnt pine forest due to the arrival of opportunistic species after the wild fire. Species adapted to open areas were captured in the burnt pine zone whereas species detected in the control forest are characteristically located in areas covered by a lot of vegetation or in grasslands, needing more humidity and therefore not tolerant to prevailing post-fire drought conditions. © 2004 Elsevier SAS. All rights reserved. Keywords: Pine forest; Fire; Carabidae; Recolonization; Spain 1. Introduction fire because they are mostly decomposers and there is more food available for them and have many characteristics re- Many insects have developed their own survival or recolo- quired for use as an indicator taxon [38] that permit to nization strategies [14,26] in ecosystems that are frequently evaluate the impact of the disturbances on the ecosystems affected by fire.A relatively high number of insects including and changes in habitat. Various authors such as Winter [40], predators [2], wood-borers, soil-dwellers [27] or pyrophilous Collet and Neuman [5], Sgardelis et al. [32], McCoullough et insects respond positively to heat and smoke [10,11].In al. [24], Dajoz [6] have studied changes in carabid popula- Europe, about 40 species of pyrophilous insects are favored tions after a wild fire. This paper reports the effect of burning by fire [39]; most of them are Coleoptera, and some are on species richness, abundance, equitability and diversity of carabids. According to García-Villanueva et al. [15], the first carabid fauna. Differences in the Coleoptera community in a insects to colonize a burnt Quercus sp. forest were carabids, burnt pine forest and in an unburnt one were compared. belonging mainly to the genera Steropus and Calathus. They are more opportunistic in comparison to the fauna of unaf- fected forests. These pyrophilous insects take advantage of 2. Materials and methods * Corresponding author. Tel.: +34-979-10-8392; 2.1. Study area fax: +34-979-10-8440. E-mail address: [email protected] The study area is located in Ferreras de Abajo (Zamora (M.M. Fernández Fernández). province, Spain). It is a natural Pinus pinaster forest of © 2004 Elsevier SAS. All rights reserved. doi:10.1016/j.ejsobi.2004.01.003 48 M.M. Fernández Fernández, J.M. Salgado Costas / European Journal of Soil Biology 40 (2004) 47–53 11 500 ha with 2500 trees per ha that had been subjected to 2.3. Data analysis wild fire in June 1996. A total of 640 ha were burnt. Both sampling areas, each with an area of 1000 m2 are situated on Diversity was calculated using the Shannon and Weaver ′ ͚ a gentle slope with northern exposure at an altitude of 900 m index [33] as H =– Pi*log2 Pi, where Pi is the relative ′ above sea level. The first sampling area is in the burnt zone frequency of each species. Equitability is E = H /log2 N. ′ ͚ 2 ͚ (Bp) and the second one in the unburnt zone (control pine Variance was calculated as Var = H = Pi(log2 Pi) –( Pi 2 2 forest, Cp). The climate is Mediterranean with a dry period log2 Pi) /N –[S – 1/2N ] were Pi, relative frequency for each from July to September, mean annual temperature of 11.5 °C species; S, number of species – 1; N, total number of speci- and mean annual rainfall of 692.6 mm [25]. mens. A v2-test was used to compare species richness be- tween the two areas for each sampled month. An v2-test was 2.2. Sampling method used to compare the species that had fallen into the beer, liver and water traps in Cp and Bp. Sampling was started 10 months after the fire. Carabids A principal component analysis [37] was also applied to were captured using 18 pitfall traps (glass vials 6 cm in relate species data obtained using the attracting traps in both diameter and 12 cm deep, buried just below the ground study areas and type of forest. The type of forest, the bait surface) with different types of attracting baits: three liver used as well as the distance to the firebreak were all tested by baits, three beer baits and three water baits (the last with a ANOVA [36]. Finally, all the captured specimens were mea- few drops of formol) were placed in both burnt and control sured. Total length was taken from the margin of clypeus to areas. Beer traps as well as other fermented liquids have been apex of elytra. A Student’s t-test was applied in order to tested as attractant for carabids [29,31]. Water traps are often compare significant differences between the mean body used for the capture of carabids [20,35]. Finally, liver is the length of carabids captured in both pine forests for each most effective bait used in the capture of necrophagous, but sampled month. often, a lot of carabids were found inside due to the fact that liver provides a high number of Diptera larvae that will be 3. Results and discussion used as food for carabids [1,12,28]. Cannibalism has been noticed by several authors [4,17,23], but in this study it was 3.1. Abundance and trap selectivity not important because of the high presence of Diptera larvae. The traps containing liver were covered with a perforated lid A total of 393 Carabidae specimens were captured. so that the insects could get in but ensured that would not be Greater abundance was recorded for the beer baits, followed eaten by small mammals. The beer and water traps were by the water and liver baits, respectively, in both study areas. buried in the same way without a lid and filled to 2/3 of their Using a v2-test and taking into account the species appearing capacity. They were all covered with a flat stone to prevent in the different baits, significant differences were observed excess evaporation or rainwater getting in and damaging the only amongst those species caught in the beer baits in Bp and attracting baits but with enough space to allow entry of Cp (v2 = 23.6; P < 0.05). carabids. Data on abundance, species richness, equitability, diver- The pitfall traps were placed along transects at 50 m sity and variance for each studied area is shown in Table 1. intervals. The first one was placed on the outer limit of the Greater abundance was observed in the burnt zone. Diversity sampling area, coinciding with the firebreak. The second one was similar in both pine zones and no significant differences was placed at a distance of 50 m from the first, and the third, were noticed (t = 1.94, n = 208, P < 0.10). 100 m, towards the inner part. All the traps were located perpendicular to the firebreak (Fig. 1). In all, nine traps were 3.2. Composition of the carabid community placed in the burnt pine forest and nine in the control. They were collected about every 12–15 days for 6 months (April– The carabid community in the burnt area was different October 1997). from that in the control zone (Table 1). Species adapted to Burntp ine forest Control pine forest 100 m. 50 m. 100 m. Firebreak Fig. 1. Plot design for each experimental pine forest. White circles represent water traps, grey circles indicate beer traps and black ones, the liver traps. M.M. Fernández Fernández, J.M. Salgado Costas / European Journal of Soil Biology 40 (2004) 47–53 49 Table 1 Number of captured specimens for each species in both burnt and control pine forest with each type of bait (B, beer; W, water; L, liver). Data on species richness, equitability, diversity and variance Burnt pine forest Control pi deforest BWLBWL A. aenea 720000 C. dejeanni 3302423 C. mollis 110200 C. piceus 1400800 C. uniseriatus 850000 H. neglectus 1580000 N. salina 46 2 2 11 9 2 O. rufipes 300000 O. gestchmanni 100000 Platyderus sp.0 00010 P. coerulescens 000210 P. kugelanni 0002960 S. globosus ebenus 65 69 14 0 0 0 T. obtusus 000100 T. quadristriatus 0001211 Total (%) 193 (64.7) 87 (29.1) 18 (6.2) 69 (72.6) 20 (21) 6 (6.4) Total 298 95 Species richness 10 9 Equitability 0.68 0.77 Diversity 3.32 3.16 Variance 0.007 0.014 open areas, such as Amara aenea, Calathus uniseriatus, were related to fire and type of bait,whereas the distance to Harpalus neglectus, Ophonus rufipes, Oreocarabus gestch- the firebreak only affected the abundance of A.