(Coleoptera: Carabidae) Responses to a Forest Wildfire in Northern Europe
Total Page:16
File Type:pdf, Size:1020Kb
Russian Entomol. J. 17(3): 273282 © RUSSIAN ENTOMOLOGICAL JOURNAL, 2008 Ground beetle (Coleoptera: Carabidae) responses to a forest wildfire in northern Europe Ðåàêöèè æóæåëèö (Coleoptera: Carabidae) íà ëåñíîé ïîæàð â Ñåâåðíîé Åâðîïå Konstantin B. Gongalsky1, Lars-Ove Wikars2 & Tryggve Persson2 Ê.Á. Ãîíãàëüñêèé1, Ë.-Ó. Âèêàðø2, Ò. Ïåðøîí2 1 A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33, Leninsky pr., Moscow, 119071, Russia. 1 Èíñòèòóò ïðîáëåì ýêîëîãèè è ýâîëþöèè èì. À.Í. Ñåâåðöîâà ÐÀÍ, Ëåíèíñêèé ïðîñïåêò 33, Ìîñêâà 119071, Ðîññèÿ. 2 Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7044, Uppsala, SE-750 07, Sweden. KEY WORDS: forest fire, pyrophilous carabids, Carabidae ÊËÞ×ÅÂÛÅ ÑËÎÂÀ: ëåñíîé ïîæàð, ïèðîôèëüíûå æóæåëèöû, Carabidae ABSTRACT. Carabid beetles were studied for two ñòàëè äîìèíàíòàìè, ïðè÷åì S. quadripunctata âñòðå- years following an extensive wildfire in a pine forest area ÷àëàñü â îñíîâíîì íà ñèëüíî, à P. quadrifoveolatus with shallow soil close to Stockholm. The beetles were íà ñëàáî âûãîðåâøèõ ó÷àñòêàõ. Îêîëîâîäíûå âèäû collected in pitfall traps placed at six plots along a 1.2-km áûëè îáû÷íû â òå÷åíèå ïåðâîé âåñíû ïîñëå ïîæà- line-transect from the unburnt forest (control) to the ðà, âåðîÿòíî èç-çà òîãî, ÷òî îíè ïåðåæèëè ïîæàð â centre of the burnt area. Two of the plots in the centre of áîëîòèñòûõ ïîíèæåíèÿõ â ëåñó. Íàèáîëüøàÿ ÷èñ- the area differed in fire behaviour. The pyrophilous ëåííîñòü è ðàçíîîáðàçèå æóæåëèö áûëè îòìå÷åíû carabids Sericoda quadripunctata and Pterostichus íà ñëàáî âûãîðåâøèõ ó÷àñòêàõ ïî ñðàâíåíèþ ñ ñèëü- quadrifoveolatus became readily dominating, of which S. íî âûãîðåâøèìè è íåòðîíóòûì ëåñîì. Äàæå ëåñíûå quadripunctata seemed to be favoured by severe burning âèäû áûëè áîëåå ìíîãî÷èñëåííû íà ñëàáî âûãîðåâ- and P. quadrifoveolatus by weak burning. Close-to-wa- øèõ ó÷àñòêàõ ïî ñðàâíåíèþñ ñ ëåñîì, ÷òî ìîæåò ter-habitat specialists were fairly common during the first áûòü îáúÿñíåíî áîëåå âûñîêîé ìîáèëüíîñòüþ æó- spring after the fire, probably because they could survive æåëèö íà ïîæàðèùå èç-çà îòñóòñòâèÿ ìîõîâî-ëè- the fire in swampy depressions. The carabids were more øàéíèêîâîãî ïîêðîâà. Êîëè÷åñòâî âèäîâ íå îòëè- abundant and rich in species in the least severely burnt ÷àëîñü ìåæäó ïîæàðèùåì è íåãîðåëûì ëåñîì. Ñëà- area than in the unburnt forest or in the severely burnt áî ñãîðåâøèé ëåñ ìîã âûñòóïàòü â êà÷åñòâå óáåæè- plots. Even the carabids classified as forest species were ùà âî âðåìÿ ïîæàðà è ñîäåðæàòü çíà÷èòåëüíî áîëü- more commonly collected in the weakly burnt area than øåå êîëè÷åñòâî ïèùåâûõ ðåñóðñîâ ïî ñðàâíåíèþ ñ in the forest, which might be explained by higher carabid ñèëüíî âûãîðåâøèìè ó÷àñòêàìè. Èíòåíñèâíîñòü mobility due to less ground vegetation than in the forest. ïîæàðà, à íå ðàññòîÿíèå äî êðàÿ ëåñà îïðåäåëÿëè The number of species did not differ in a consistent way ïëîòíîñòü ïîïóëÿöèé æóæåëèö íà ïîæàðèùå â òå÷å- between the unburnt and burnt forest. The weakly burnt íèå äâóõ ëåò ïîñëå ïîæàðà. forest might have served as a partial refuge during the fire and might also have kept a greater amount of prey than the more severely burnt areas. Fire severity rather than dis- Introduction tance to the forest edge seemed to determine the popula- tion densities during the first two years after the fire. Natural forest fires have been an extensive and recurrent phenomenon in boreal forests of Northern ÐÅÇÞÌÅ.  òå÷åíèå äâóõ ëåò èçó÷àëè ñîîáùå- Europe [Zackrisson, 1977; Niklasson & Granström, ñòâà æóæåëèö ïîñëå ñèëüíîãî ïîæàðà â ñîñíîâîì 2000]. A diverse set of organisms needs fires, especially ëåñó íà ñëàáîðàçâèòûõ ïî÷âàõ â îêðåñòíîñòÿõ Ñòîê- insects and fungi [Esseen et al., 1997]. Due to efficient ãîëüìà (Øâåöèÿ). Æóêîâ ñîáèðàëè ñ ïîìîùüþ ëî- fire suppression, the area affected by wildfire has de- âóøåê Áàðáåðà, ðàñïîëîæåííûõ íà øåñòè ó÷àñòêàõ creased more than 100-fold during the last 100 years in ïî òðàíñåêòå äëèíîé 1,2 êì îò íåãîðåëîãî ëåñà (êîí- Sweden. Many fire-dependent species have experienced òðîëü) ê öåíòðó ïîæàðèùà. Äâà ó÷àñòêà â öåíòðå range contractions, and a few of them have already gone ïîæàðèùà ðàçëè÷àëèñü ïî ñèëå âûãîðàíèÿ. Ïèðî- nationally extinct [Gärdenfors, 2000; Kotze & OHara, ôèëüíûå æóæåëèöû Sericoda quadripunctata è 2003]. Prescribed fires by forestry and conservation Pterostichus quadrifoveolatus âñêîðå ïîñëå ïîæàðà agencies are today regularly made in Sweden for con- 274 Konstantin B. Gongalsky, Lars-Ove Wikars and Tryggve Persson servation purposes to favour fire-dependent species hypothesized that fire-dependent species should be [Granström, 2001]. quick invaders in the area, be favoured by fire severity Wildfires are extremely variable, and the effects will and prefer the central part of the fire, whereas other depend on both deterministic and stochastic factors species should recover more slowly and gradually in- [Johnson & Miyanishi, 2001; Certini, 2005]. For soil- crease their populations from the edge of the surround- dwelling arthropods, the burning of the organic soil by ing, unaffected forest towards the fire centre. glowing fires in the humus layer will determine to what extent the organisms survive [Ahlgren, 1974; Wikars & Materials and methods Schimmel, 2001]. The amount of soil consumption will, in turn, depend on soil moisture before the fire [Schim- Study area mel & Granström, 1996]. However, soil burning also In August 1999, a wildfire affected an area of 450 ha differs between dry and wet vegetation types [Ryan, in the central part of Tyresta National Park and Nature 2002]. The post-fire assemblage will presumably de- Reserve, which together make up 4700 ha of predomi- pend on to what extent the fauna has survived, the nantly coniferous forests. The area is situated 20 km immigration capacity of the fauna and vegetation suc- south of Stockholm in central Sweden (59°10´ N, 18°20´ cession. Spatial patterns during colonisation may be E). Mean annual temperature and precipitation is 6.6 °C important if a large area is affected by fire, but have and 539 mm, respectively, at the nearest meteorological seldom been reported. station in Stockholm. The area is heterogeneous be- Several studies have been made on carabid beetles cause of numerous fissure valleys. Protruding areas following forest fires in boreal forest. Most studies have consist of undulating rocky outcrops, and mires/swamps compared unburnt and burnt forests or focussed on the and lakes fill the depressions. A sparse forest of Scots post-fire succession [Winter, 1980; Richardson & Hol- pine (Pinus sylvestris L.) and common silver birch liday, 1982; Gardner & Usher, 1989; Holliday, 1992; (Betula pendula Roth) is growing on the outcrops, Muona & Rutanen, 1994; Wikars, 1995; Fernández whereas the mire elements are to a large extent covered Fernández & Salgado Costas, 2004; Saint-Germain et by Scots pine and hairy birch (Betula pubescens Ehrh.). al., 2005]. However, few studies have focussed on the The pine forest is dominated by 150300 year-old trees effects of the heterogeneity within a recently burnt area and has never been affected by large-scale forestry. on carabid beetles. Norway spruce (Picea abies (L.) Karst.) and aspen The aim of this study was to determine the effects of (Populus tremula L.) mostly grow on slopes and seldom a wildfire on carabid beetles in central Sweden. We form stands in the burnt area. Fig. 1. The study area in Tyresta National Park (Sweden) affected by a wildfire in 1999. Arabic numbers tha sampling plots. Ðèñ. 1. Ðàéîí ïðîâåäåíèÿ èññëåäîâàíèé íàöèîíàëüíûé ïàðê Òþðåñòà (Øâåöèÿ), íà òåððèòîðèè êîòîðîãî â 1999 ã. ïðîèçîø¸ë ëåñíîé ïîæàð. Àðàáñêèìè öèôðàìè îáîçíà÷åíû ó÷¸òíûå ïëîùàäêè. Ground beetle responses to a forest wildfire in northern Europe 275 A long drought preceded the fire in 1999, and warm vulgaris (L.) Hull. and Vaccinium vitis-idaea L. had and windy weather made the fire intense, and it burnt probably grown before the fire, as judged from the deeply into the soil. The shallow organic soils on the regrowth observed after the fire by the latter two species bedrock were to a large extent burnt away, whereas the [Schimmel & Granström, 1996] and by comparison peat soils in the moist depressions were reduced, but with the vegetation in unburnt areas. In the moister seldom completely burnt. Crown fires affected 5% of parts, there were Sphagnum mosses, Ledum palustre L. the burnt area (Fig. 1), estimated from aerial photo- and Eriophorum vaginatum L. (based on vegetative re- graphs taken shortly after the fire [Granström, pers. growth after the fire). A documentation of the tree layer comm.]. Despite this, the fire killed more than 90% of (including soot-height on trees which indicates fire the trees because of serious root injuries and subsequent severity) and vegetation was done in October and No- blow-downs. In December 1999, a storm felled more vember 2001. On these occasions, mosses dominated than 80% of the trees, and winter storms in 19992001 the vegetation. Dominant herbs were Chamaenerion felled even more [Wikars, own observation]. angustifolium Scop., Rubus idaeus L. and Senecio spp., together with regenerating species such as Calluna vul- Sampling plots garis L., Vaccinium vitis-idaea L., and V. myrtillus L. Carabid beetles were sampled at six different plots, 30x30 m, one unburnt (0) and five burnt plots (15) Sampling during 20002001 (Table 1, Fig. 1). The control plot (0) Carabid beetles were sampled by 40 Barber pitfall consisted of a pine forest ca. 200 m from the edge of the traps consisting of 6 cm wide and 8 cm deep plastic jars burnt area. A line transect that represented a gradual that were placed at the level of soil surface. The distance increase in distance (plots 13) from the forest edge was between traps was 35 m. The jars were filled with 50% established, and at the end of this transect two plots with propylene glycol and a detergent.