辽宁奉国寺彩绘泥塑木骨架生物病害研究

Investigation and research on the biodegradations of wooden skeletons of painted clay sculptures in Fengguo Temple,Liaoning

辽宁义县奉国寺的彩绘泥塑群中多尊泥塑发生倾斜,初步勘察为木骨架糟朽导致。为确认木骨架糟朽原因,经过现场勘察,采集糟朽木骨架木材、进行树种鉴定、微生物分离和甲虫尸体鉴定。结果显示:两彩绘泥塑木骨架样品分别为硬木松(Pinus sp.)和杨木(Populus sp.);真菌多样性测序结果表明子囊菌门霉菌为优势真菌,从糟朽木材中分离到一株曲霉(Aspergillus sp.),未见其他腐朽菌;虫体经鉴定为鞘翅目象甲科、窃蠹科、皮蠹科和拟步甲科昆虫。辽宁位于木材腐朽危害中等风险区域(D2),分析认为木骨架糟朽的原因主要为窃蠹和象甲科害虫危害导致,根据甲虫的侵染途径和生长特性,推断木骨架木材在应用之初或者维修替换的新木材未进行预处理,没有杀灭虫卵导致虫卵孵化为幼虫,底部被蠹虫幼虫蛀空导致倾斜。经进一步对奉国寺建筑木构件勘察发现部分柱、梁等构件也出现直径3 mm左右蠹虫羽化孔,说明彩绘泥塑所处的古建筑木构也存在类似的虫害。本研究揭示了窃蠹和象科甲虫对彩绘泥塑的破坏影响,说明了彩绘泥塑木骨架与古建筑木构件在加工使用前进行预防性保护的重要性,为彩绘泥塑的生物病害预防和维修工程中木材防虫害预处理提出了建议。

Several painted clay sculptures in Fengguo Temple in Yixian County,Liaoning Province,showed the severe problem of leaning.A preliminary investigation was conducted,and it was concluded that the inclination was caused by the decay of the wooden skeletons inside the sculptures.With the aim of defining the reason for deterioration of the wooden skeletons,collection of decayed samples in an on-site investigation was carried out,in order to determine the species of the wood samples and the microbes and to identify dead insect corpses.The results show that:1)the two wood samples were hardwood pine(Pinus sp.)and poplar(Populus sp.);2)there was no wood-decaying fungi,only one strain of the mold,Aspergillus sp.was isolated,and Ascomycota fungi were the main species,according to fungal diversity analysis;3)insects were identified as Coleoptera beetles,belonging to 4 families,namely Curculionidae,Anobiidae,Dermestidae and Tenebrionidae.Considering that Liaoning is located in the moderate decay hazard zone(D2)in the wood decay hazards map,the primary influence of the deterioration is mainly due to beetles.It is speculated that there was no pretreatment against the larvae and eggs of beetles,or that the pretreatment was not thorough,and later the eggs were hatched and then damaged skeleton wood,finally causing the sculptures to incline.In addition,further investigations show that some columns,beams and other wooden structures in the main hall also had emergence holes with a diameter of about 3 mm,indicating that there is some connection between the sculptures and the building when the biological hazard exists.This research reveals the impact of biodeterioration on the painted clay sculptures and the importance of preventive treatments for wooden skeletons inside the sculptures,and also provides ideas for the preventive conservation and conservation protocols to be designed for clay sculptures in Fengguo Temple and other wooden heritage structures.