Estimation of Timber Production of Five Species of the Tamaulipas Thorny Shrubs Growing in Native Stands and Plantations

Shrub species have a great capacity to develop in extreme climatic conditions;this ability has a direct influence on their development and productivity in timber and firewood. In this paper, the timber’s production of experimental plantation aged 28 years of Acacia berlandieri (Benth.), Havardia pallens (Benth.) Britton & Rose, Helietta parvifolia (Gray) Benth., Ebenopsis ebano (Berl.) Barneby and Acacia wrightii (Benth.) species is quantified and compared with the production of the same species developed naturally in the native bush. The variables recorded were the number of shoots per tree, total height, basal diameter and diameter at breast height of each tree to determine the volume of wood with the Smalian equation. The results indicate that the volume of usable wood was higher in experimental plantation than that on native vegetation for H. parvifolia, A. berlandieri and H. pallens. The species that produced the highest volume of timber were H. parvifolia (0.396 m3·ha-1·year-1) in plantations and E. ebano (0.118 m3·ha-1·year-1) in native shrubs, species with lower production were H. pallens (0.059 m3·ha-1·year-1) and A. berlandieri (0.052 m3·ha-1·year-1) in the native area. The highest number of shoots was registered for A. berlandieri and H. parvifolia, with eight shoots per tree in experimental plantations of both species compared with native vegetation, which was five and three shoots per tree respectively. These results high-light the importance of developing plantations in degraded areas of scrub, which can increase timber volume production.

Geochemistry and mineralogy of beach sediments in the northern Gulf of Mexico,Tamaulipas state,Mexico:implication for provenance

Geochemical and mineralogical studies were performed in the La Pesca(LP)and Tesoro Altamira(TA)beach sediments,located in the Tamaulipas state,northern Gulf of Mexico.The main aim of this study is to infer the weathering history and provenance and to discriminate the tectonic environment of the beach sediments.The sediments are composed of quartz with small amounts of accessory minerals such as plagioclase,calcite,orthoclase,microcline,and zircon.Both beach sediments are classified as fine-grained and very well sorted,however LP has coarse skewed and leptokurtic sediments,whereas TA has fine-skewed and very leptokurtic sediments.The chemical index of weathering(CIW’)indicates intense weathering in the source area.The quartz grain microtextures in the LP and TA are classified into mechanical,chemical,and mechanical/chemical origin.Mechanical features such as fractures,pits,percussion marks,abrasion fatigue,and V-shaped marks favor high-energy littoral,fluvial,subaqueous-marine,and aeolian environments.The chemical features indicate solution pits and crystalline overgrowth,which suggests a silica saturated marine environment.The mechanical/chemical features display adhering particles and elongated depressions suggest formation in a sub-aqueous nearshore marine environment.Major and trace elements-based provenance discrimination diagrams indicate a felsic source derived from the Mesa Central(MC),Sierra Madre Oriental(SMOr)and Oaxaquia terranes.The major and trace element concentrations imply a passive margin setting for the northern Gulf of Mexico,which is consistent with the general geology.

First record of Leucoagaricus lilaceus(Agaricales:Agaricomycetes)in Mexico

Leucoagaricus lilaceus is recorded for the first time in Mexico.This species is characterized by the purplish pileus,whitish to pinkish gills and a wide bulbose base.The next record represents the northernmost distribution of this species so far in America.Microscopic and macroscopic features are described and illustrated.