The Contribution of Non-Wood Forest Products to Rural Livelihoods in Tunisia: The Case of Aleppo Pine

Research Highlights: Recently, there has been a growing interest in the contribution of Non-Wood Forest Products (NWFPs) to livelihoods and food security among local populations in Tunisia. NWFPs have gained special attention given the relevance of this forest heritage to alleviate poverty and improve household economies. Background and Objectives: This study focuses on determining the contribution of Aleppo pine production to local household livelihood and food security in Tunisia (Siliana province). The relevance of this region as a leading Tunisian Aleppo pine producer makes the analysis especially interesting. Materials and Methods: Data were obtained using structured surveys distributed among rural household heads during the collection season. A logistic regression as well as food security indicators were calculated to evaluate the contribution of NWFPs to household livelihood. Results: Empirical findings support evidence that there is a significant difference between the alternative sources of revenues. The collection of Aleppo pine was significantly affected by gender, attending extension days and agricultural training program, distance to market, household size and livestock activity. Conclusions: Aleppo pine plays an important role in supporting rural livelihoods and provides an important safety net for the local population throughout the year.

Nitrogen Deposition in Different Mediterranean Forest Types along the Eastern Adriatic Coast

Mediterranean forests along the eastern Adriatic coast have an important ecological role. However, few studies have been conducted on nitrogen deposition so far. To improve this knowledge, the main aims of our study were: (i) to estimate nitrogen inputs and determine differences among the four Mediterranean forests, (ii) to determine the seasonal behaviour of N deposition compounds, and (iii) to discuss the results in relation to forest type and precipitation. Measurements were carried out over a two-year period on four plots in two regions: holm oak and pubescent oak in Istria, Aleppo pine and black pine in Dalmatia. Bulk open field and throughfall deposition were sampled with continuously exposed collectors. Measurements, analyses and data validation of precipitation and N compounds were carried out. The results showed that the highest average monthly precipitation was recorded in the black pine plot and the lowest in the Aleppo pine plot. Nitrate and ammonia in conifer plots in throughfall samples were lower than in bulk open field samples, indicating possible retention by the tree canopy. The results revealed a higher amount of N deposition collected in broadleaved forests than in conifer forests indicating the washing out of N compounds previously deposited and accumulated in forest canopy. The chemistry of N deposition was strongly influenced by local and anthropogenic sources as well as neighbouring countries. Our results may fill the knowledge gap in understanding the influence of precipitation and seasonality of N compounds in different Mediterranean forest types along the eastern Adriatic coast.

Clumped or regular? the role of thinning pattern on pine growth and soil water content in dense Aleppo pine post-fire stands

The development of silvicultural practices that seek to promote structural heterogeneity is increasingly demanded. This work investigates the effect of thinning spatial pattern on the response to pre-commercial thinning of dense Aleppo pine post-fire stands. On three replicated experimental sites in SE Spain, we applied the following treatments: 600 trees/ha, regular thinning pattern (600R), with residual trees evenly spaced; 600 trees/ha, aggregated thinning pattern (600A), with residual pines arranged in clumps of ∽25 trees with a local within-clump density of 2500 trees/ha; and control treatment, with no thinning applied (> 20,000 trees/ha). We assessed treatment effects on pine growth, size-growth relationships, soil water content, and understory vegetation over the first three years after thinning application. Both regular and aggregated thinning pattern similarly increased pine radial growth. In general, dbh growth rates in response to thinning were faster for smaller trees than for larger trees. The growth rate of pine height was higher for 600R and control than for 600A, indicating a positive effect on height of both low and very high pine densities. We found a near-term positive effect of aggregated pattern on water availability at the stand level, mostly resulting from enhanced soil water content in the canopy gaps. For both thinning patterns, the recovery of understory vegetation was dominated by resprouter species. This study highlights the potential of aggregated thinning patterns to enhance the complexity and heterogeneity of the pine stands without compromising pine growth, which could be of great use to managing pine forests in Mediterranean areas.

Production Potential and Development of a Decision Support Models for the Plantations of Aleppo Pine in the Oued Laou Watershed in the Moroccan Rif

The present study was carried out in the Oued Laou watershed belonging to the Moroccan Rif. It aims at the elaboration of mathematical tariffs for cubing Aleppo pine, the morphometric and increments study. The data analyzed for this purpose were collected after a preliminary stratification of the forest based on the plantation age. The study of the region’s climate shows that the western sector of the watershed is part of the temperate humid bioclimate, and the eastern sector belongs to the warm variant subhumid. The analysis of the stand-study structure shows that the distribution of the number of stems as a function of the circumference is a distribution close to normal. Cubic rates have been constructed to estimate the volume of trees. The mean annual volume increment of Aleppo pine varies between 3.10 and 4.83 m3/ha/year from one plot to another; this small fluctuation largely reflects the homogeneity of the study area. Aleppo pine has a wide ecological and spatial plasticity: colonization of all substrates, bioclimates ranging from semi-arid to temperate humid. It’s a species that exhibits uniform behavior despite topographic and edaphic variations.

Investigating the prevalence of Bark beetles of Pinus halepensis in the North East semi-arid region of Algeria

Moumeni L, Gastebois A, Gillmann L, Papon N, Benia F, Bouchara J-P, Bounechada M. 2021. Investigating the prevalence of Bark beetles of Pinus halepensis in the North East semi-arid region of Algeria. Biodiversitas 22: 2755-2762. Aleppo pine is the most common tree in the semi-arid forests of Algeria. Despite its high resistance to drought and adaptability to all types of soils, the effects of climate change are affecting it directly and indirectly. Stressed trees indeed are subject to bark beetle attacks. In this study, we sampled the bark beetles directly from the affected pine trees. Six species belonging to the Scolytinae subfamily were identified. Tomicus detruens and Orthotomicus erosus were widely spread and present in the three studied forests, where they were found to colonize living trees while Crypturgus numidicus, Crypturgus mediterraneus, Hylurgus ligniperda and Hylurgus micklitzi colonized only dead trees. Together with future identification of the microfungi associated with these xylophagous insects, these data may help to define prevention measures to fight the decline of Aleppo pine forests observed in some parts of Eastern Algeria.