Ancient Woods, Trees and Forests

As trees age, they become ecologically richer and more full of life. The process of a tree, wood or forest becoming ‘ancient’, however defined, involves a vast and subtle web of relations – among the trees themselves, with other organisms, with the wider landscape and with human beings. A single tree can provide a vast array of habitats which are an integral part of the complex co-evolutionary relationships evolved over its lifetime and later during its sometimes long afterlife. From ancient times until today, trees and woods have inspired artists, writers and scientists; they have shaped cultures and reverberated through belief systems. Yet worldwide, forest cover has declined dramatically over the last 1,000 years, and what remains has been more or less altered from its original condition. Today, ‘virgin forests’ are only to be found at a few sites unreachable by humans, and even then they are affected by climate change, atmospheric pollution and species extinctions. The aim of this book is to help an understanding of the web of connections relating to ancient trees and woodlands, and to offer techniques to ensure effective conservation and sustainability of this precious resource. This book considers the key issues from a range of different aspects and varied geographical locations, beginning with fundamental concepts and reflecting on the strengths and limitations of the idea of ancient trees. Individual chapters then deal with cultural heritage, the archaeology of trees, landscape history, forest rights, tree management, saproxylic insects, the importance of dead wood, practical conservation and monitoring, biodiversity, and wood pasture among many other themes. Fresh perspectives are put forward from across Europe as far as Turkey, as well as Great Britain. Overall, given the urgent need to discover, understand, conserve and restore ancient woodlands and trees, this publication will raise awareness, foster enthusiasm and inspire wonder.

Census of the longhorn beetles (Coleoptera, Cerambycidae and Vesperidae) of the Macau SAR, China

An intensive census, extended over a period of approximately three and a half years, October 2017– May 2021, was conducted in the remaining green areas of the Macau SAR in order to provide an updated status of the biodiversity of longhorn beetles in this region. This insect group includes more than 36,000 species worldwide, subdivided into four families of mainly xylophagous or saproxylic insects, the Vesperidae, Oxypeltidae, Disteniidae, and Cerambycidae. They are of key importance in agricultural and forestry science, and are often used as an indicator of forest habitat health. A total of 52 species was recorded during this census, 2.6 times more than previously reported in the literature for this area. However, recorded abundances and frequency of occurrence for the various species were remarkably low, and of the 20 species previously reported for the region, some prominent ones remained unaccounted for. Among others, these include Batocera horsfieldii (Hope, 1839), Apriona rugicollis Chevrolat, 1852 [previously incorrectly reported as Apriona germarii (Hope, 1831)], Aristobia reticulator (Fabricius, 1781) [previously reported as Aristobia testudo (Voet, 1778)] and Imantocera penicillata (Hope, 1831). It is hypothesised that this may be related to the ongoing manipulation of the natural vegetation of the Macau SAR, which is rapidly being converted to plantations, city parks, and gardens. In particular, dead or dying trees and lower tree branches are systematically removed in order to improve the aesthetic appearance of these green areas. However, this process is also depriving xylophagous and saproxylic species of their essential habitats.

Saproxylic beetles (Insecta: Coleoptera) on an old beech (Fagus sylvatica L.) in Madonie Mountains (Sicily, Italy)

Saproxylic insects associated with old trees are seriously threatened in Europe and their habitat is severely decreased. Usually, old trees harbour a very diverse fauna of beetles with many rare species and red-listed saproxylic insect species. These insects live in the dead wood outside the tree (in branches or parts of the trunk), inside the tree hollows, in the debris, and in fungal fruit bodies. During 2019 we collected saproxylic beetles near Monte Carbonara (Madonie Mountains, Sicily, Italy) at 1800 meters above sea level. Particularly, we studied a very old still standing beech (Fagus sylvatica L.), t with numerous cavities and parts of the trunk fallen to the ground. Samples were collected by visually looking for beetles, on the ground and under leaves near the old beech, in its cavities and sifting the debris in the laboratory. Up to date the results include interesting beetle species such as Osmoderma cristinae Sparacio, 1994 (Cetoniidae), Byrrhus numidicus Normand, 1935 (Byrrhidae), Rosalia alpina (Linnaeus, 1758) and Morimus asper Sulzer, 1776 (Cerambycidae).

The attraction of Tremex apicalis (Hymenoptera, Siricidae, Tremecinae) and its parasitoid Ibalia japonica (Hymenoptera, Ibaliidae) to the fungus Cerrena unicolor

Woodwasps (Hymenoptera: Siricidae) are saproxylic insects and a common forest pest. Siricid woodwasps are classified into two subfamilies: Siricinae and Tremecinae. All known symbiotic fungi of Siricinae are in the genusAmylostereumBoidin while some species of Tremecinae have been observed to have a relationship with the fungusCerrenaunicolor(Bull.) Murrill. Previous studies about the host searching behavior of woodwasps and their parasitoids have focused primarily on the subfamily Siricinae.We analyzed the role ofC.unicolorvolatiles on the host searching behavior ofTremexapicalisMatsumura (Hymenoptera: Siricidae: Tremecinae) and its parasitoid Ibalia (Tremibalia) japonica Matsumura (Hymenoptera: Ibaliidae). The results of an olfactory response experiment indicated that the females ofT.apicalisand its parasitoid find their respective hosts using volatiles fromC.unicolor. Using DNA barcode, we identified basidiocarps on the trees infested withT.apicalis.The basidiocarps were all white-rot fungi that cause sapwood decay, includingC.unicolor. Two additional species that we identified belonged to genera closely related toC.unicolor.Woodwasp species are known to carry symbiotic fungi in a pair of specialized sacs called mycangia. Notably we found that mycangia-like structures were absent in the abdomens ofT.apicalisfemales. To the best of our knowledge,Xerisspectrum(Linnaeus) (Hymenoptera: Siricidae) is the only reported example of woodwasp species that do not contain symbiotic fungi in their bodies.Our results suggested that: (1)T.apicalisfemales search for host wood that is already infected with sapwood decaying fungus using volatile compounds; (2)T.apicalis’ female parasitoid also uses volatile compounds from fungus to locate wood that is infested with its potential host.