Stand structure and regeneration of Cedrus libani (A. Rich) in Tannourine Cedar Forest Reserve (Lebanon) affected by cedar web-spinning sawfly (Cephalcia tannourinensis, Hymenoptera: Pamphiliidae).

Abstract

The analysis of forest structure is a useful tool to understand stand biodiversity characterizing forest ecosystems, and could help in suggesting appropriate management plans. Cedar forests in Lebanon are remnant patches that survived past human activities but are still threatened by other different anthropogenic and natural disturbances. Among these threats, the cedar web-spinning sawfly (Cephalcia tannourinensis) discovered in Tannourine Cedar Forest Nature Reserve in 1997, which is able to cause the death of trees. The aim of this study is to investigate the impact of this pest on the stand structure and regeneration of Cedrus libani in Tannourine Cedar Forest Nature Reserve located in North Lebanon. The dependence of stand structural attributes (diameter at breast height, total height and basal area) on the presence of infestation by the cedar web-spinning sawfly was identified using the Student's ttest. The Ripley's K(d) function was used to analyse the spatial pattern of cedar stands. In addition, the diameter, the vertical structure and the crown projection were characterized using the Weibull function and graphic representations. The results showed that stand structure and regeneration are significantly different between infested and non-infested stands. The cedar of Lebanon remains as the dominant species, with abundant young individuals and a good regeneration status (c = 1.0). The analysis of the spatial pattern showed a positive spatial relationship between mature Lebanese cedar trees as well as between mature and juvenile cedars, with a bigger aggregation in infested plots (6 to 10 meters) than in non-infested quadrates (2 to 7 meters), reflecting the impact of the cedar web-spinning sawfly on the stand structure and regeneration of Cedrus libani stands.

Assessment of How Natural Stand Structure for Narrow Endemic Cedrus brevifolia Henry Supports Silvicultural Treatments for Its Sustainable Management

“…In the PRCSA and PRCSB the basal area of the species is 36.47 and 38.49 m 2 •ha -1 respectively (Table 1). These values are higher compared to the value of C. libani basal area referred for stands in Tannourine Cedar Forest Reserve in Lebanon (Bassil et al 2018), but they are lower than the basal area of pure C. atlantica forests in Theniet El Had National Park in Algeria (Sarmoum et al 2018) and the values of C. atlantica basal area of most closed stands in the Moroccan Middle Atlas forests (Linares et al 2011). In Cyprus, two groups of pure structural types are formed regarding basal area.…”

Influence of strata-specific forest structural features on the regeneration of the evergreen broad-leaved forest in Tianmu Mountain

“…Investigation and analysis of stand structure can help us understand the history, current situation, and future development of forest ecosystems and thus carry out appropriate management practices [ 26 , 30 ]. The structural characteristics of the stand affect the spatial and temporal distribution of regeneration, the quantity and quality of provenance, and the growth and death of individuals [ 4 , 6 , 44 ].…”

“…koraiensis seedlings in all experiment sites increased with the increase of opening degree in the same aspect [ 29 ]; medium mingling and random distribution were suitable for artificial regeneration of Pinus koraiensis seedlings in the secondary forest [ 28 ]. Spatial pattern analysis showed that there was a positive spatial relationship between mature Lebanese cedar trees as well as between mature and juvenile cedars [ 30 ]. Through quantifying the competitive influence of neighboring trees, Saha et al [ 31 ] indicated that the height to DBH ratio of young oak ( Quercus robur ) significantly increased with aggregate and intraspecific competition, but interspecific competition had no significant effect on the height to DBH ratio.…”

Spatial point-pattern analysis as a powerful tool in identifying pattern-process relationships in plant ecology: an updated review

“…dead vs living). For all analysis types, positive, negative, or absence of departure from the null model simulation envelopes occurs at a given scale r Hao et al 2007;De Luis et al 2008;Navarro-Cerrillo et al 2013;Kang et al 2014;Cordero et al 2016;Hu et al 2017;Miao et al 2018;Bassil et al 2018;Zhang et al 2020;Wang et al 2020b Paircorrelation function g(r) (Stoyan and Stoyan 1994) g(r) = 1 Points of the pattern are randomly distributed g(r) > 1 Points of the pattern are aggregated g(r) < 1 Points of the pattern are segregated Pélissier 1998;Wiegand et al 2007a;Suzuki et al 2008;LeMay et al 2009;Comas et al 2009;Batllori et al 2010;Wang et al 2010a;Zhang et al 2010;Martínez et al 2010;Lan et al 2012;Liu et al 2014;Petritan et al 2014;Velázquez et al 2014;Petritan et al 2015;Wang et al 2015 ;Jácome-Flores et al 2016;Nguyen et al 2016;Janík et al 2016;Fibich et al 2016;Gradel et al 2017;Wang et al 2017;Erfanifard and Stereńczak 2017;Collet et al 2017;Ghalandarayeshi et al 201...…”

“…dead vs living). For all analysis types, positive, negative, or absence of departure from the null model simulation envelopes occurs at a given scale r (Continued) Iszkuło et al 2012;Zhang et al 2013;Navarro-Cerrillo et al 2013;Ebert et al 2015;Wehenkel et al 2015;Jácome-Flores et al 2016;Jia et al 2016;Zhang et al 2016;Owen et al 2017;Gradel et al 2017;Zheng et al 2017;Nguyen et al 2018b;Omelko et al 2018;Muvengwi et al 2018;Vandekerkhove et al 2018;Kazempour Larsary et al 2018;Lv et al 2019;Baran et al 2020 Patterns 1 and 2 are segregated Riginos et al 2005;Hao et al 2007;De Luis et al 2008;Batllori et al 2010;Navarro-Cerrillo et al 2013, Kang et al 2014Cordero et al 2016;Hu et al 2017;Miao et al 2018;Bassil et al 2018; Wang et al 2010a;Zhang et al 2010;Martínez et al 2010;Lan et al 2012;Liu et al 2014;Petritan et al 2014Petritan et al , 2015Wang et al 2015;…”