Insect biodiversity reduction of pinewoods in southern Greece caused by the pine scale (Marchalina hellenica)

Abstract

This paper deals with the impact of the pine scale (Marchalina hellenica Gennadius, Hemiptera, Sternorrhyncha, Margarodidae) on the insect biodiversity of pinewoods in Attica, Greece. The comparison of biodiversities was done by estimating the biodiversity by the Ewens-Caswell V statistic in a set of nine sites each containing two linetransects. Transects pairs went through free and infested pinewoods from the pine scale and each one had several tenth hectare plots on both sides. The ecosystem temperature (= disorder) of the sites was computed and found high, together with the idiosyncratic temperatures (= susceptibility to extinction) of the 158 species in order to detect local extinctions. The indicator values of insect species were computed on the basis of the relative cover of each plant species. The main findings of this study are (1) the reduction of insect species biodiversity because of the introduction of the pine scale, (2) the moderate increase of disorder in pine scale infested sites,(3) many insect species can characterize site groups but none of them can distinguish infested from pine scale free sites. The introduction of pine scale in pinewoods disturbs their insect fauna before its influence to the floristic composition and the associated vegetation structure appears. The causes behind this reduction of biodiversity and the anthropogenic influences are discussed.

Forests of Greece, Their Multiple Functions and Uses, Sustainable Management and Biodiversity Conservation in the Face of Climate Change

“…Losses will be inevitably occurring during the time but it is important and profitable to maintain high effective population numbers for the keystone species (e.g. beech, fir, oak, pine) in order to conserve a rich biodiversity and high biodiversity quality In addition to the measures above, actions have been taken in order to increase and restore forest areas [18] [19] [52]: 1) reforestation plans (using native species and local provenances) for the restoration of fire destroyed forest areas;…”

“…Furthermore, some important evolutionary forces and actions should be considered when sustainable forest management and adaptive silviculture are applied in order to face climate change [72] [30]: 1) evolutionary dynamics of forest trees;…”

Growth and yield modelling for optimal multi-objective forest management of eastern Mediterranean Pinus brutia

“…Simulation of stand dynamics of infested pine stands reproduces logically the influence of M. hellenica on the growth and mortality of P. brutia according to the currently available scientific information (Ye il et al 2005;Gallis 2007;Petrakis et al 2010Petrakis et al , 2011. Since the influence of the scale insect on P. brutia growth was based on tree-level measurements (Ye il et al 2005), the use of an individual-tree growth model made it possible to directly incorporate the negative effect of the scale insect on tree diameter increment.…”

Predators of the giant pine scale, Marchalina hellenica (Gennadius 1883; Hemiptera: Marchalinidae), out of its natural range in Turkey

“…For this reason, it has been intentionally introduced at many natural pine forests in these countries and its population has increased locally [ 3 , 4 , 5 ]. Second, it is a pine pest as it feeds on pine sap and can cause increment loss, desiccation, branch dieback, increasing crown transparency and tree decline [ 5 , 6 , 7 , 8 , 9 ]. Furthermore, Petrakis et al [ 9 ] showed that the giant pine scale can cause decrease in diversity of pine-forest-related insects.…”