Humberto González-Rodríguez

Ethnobotany in Rayones, Nuevo León, México

BackgroundTrough collections of plants and interviews with 110 individuals, an ethnobotanical study was conducted in order to determine the knowledge and use plant species in Rayones, Nuevo Leon, Mexico. The aim of this study was to record all useful plants and their uses, to know whether differences exist in the knowledge about the number of species and uses between women and men, and to know if there is a correlation between the age of individuals and knowledge of species and their uses.MethodsA total of 110 persons were interviewed (56 men, 56 women). Semistructured interviews were carried out. The data were analyzed by means of Student t test and the Pearson Correlation Coeficient.ResultsA total of 252 species, 228 genera and 91 families of vascular plants were recorded. Astraceae, Fabaceae and are the most important families with useful species and Agave and Opuntia are the genera with the highest number of useful species. One hundred and thirty six species are considered as medicinal. Agave, Acacia and Citrus are the genera with the highest number of medicinal species. Other uses includes edible, spiritual rituals, construction and ornamentals. There was a non-significant correlation between the person’s age and number of species, but a significant very low negative correlation between the person’s age and number of uses was found.ConclusionsKnowing their medicinal uses is an important issue for the people of Rayones. Boiling and preparing infusions are the main ways of using plants by residents. The leaves, the branches, and the fruits are the most commonly used parts. Almost 18% of the flora is used for wood and construction purposes. Several uses such as cosmetic, shampoo, firming skin tonics and health hair products recorded in Rayones has not been reported for other areas in the state of Nuevo León. In Rayones, women have a greater knowledge about plants and their uses than men, particularly, medicinal plants, but, men have a greater knowledge about wood and construction species.

Acclimatation of three co-occurring tree species to water stress and their role as site indicators in mixed pine-oak forests in the Sierra Madre Oriental, Mexico

Water availability and salt excess are limiting factors in Mexican mixed pine-oak forest. In order to characterise the acclimatation of native species to these stresses, leaf water (Ψw) and osmotic potentials (Ψs) of Juniperus flaccida, Pinus pseudostrobus and Quercus canbyi were measured under natural drought and non-drought conditions under two different aspects in the Sierra Madre Oriental. Factorial ANOVA revealed significant differences in Ψw and Ψs between two aspects, species and sampling dates. In general, all species showed high predawn and low midday values that declined progressively with increasing drought and soil–water loss. Seasonal and diurnal fluctuation of Ψw and Ψs were higher for J. flaccida and Q. canbyi than for P. pseudostrobus. Leaf Ψw and Ψs were mainly correlated with soil water content, while Ψs of P. pseudostrobus were hardly correlated with environmental variables. Thus, species have different strategies to withstand drought.P. pseudostrobus was identified as a species with isohydric water status regulation, while J. flaccida and Q. canbyi presented water potential patterns typical for anisohydric species. The type of water status regulation may be a critical factor for plant survival and mortality in the context of climate change. Nevertheless, for precise conclusions about the advantages and disadvantages of each type, further long-term investigations are required.

Mineral content in range forages from north Mexico.

Native forages such as trees Quercus eduardii and Quercus grisea; shrubs such as Atriplex canescens, Acacia constricta, Acacia shaffneri, Cassia wislizeni, Celtis pallida, Condalia lycioides, Cordia parvifolia, Flourencia cernua, Larrea tridentata, Mimosa biuncifera and Prosopis leavigata; forbs such as Coldenia greggii, Dalea bicolor, Jatropha dioica and Parthenium incanum; cacti such as Opuntia imbricata, Opuntia leptocaulis and Opuntia leucotricha; red and white fruits from O. leucotricha; fruits from O. leptocaulis, O. imbricata and A. canescens; pods from P. leavigata; pods from A. shaffneri and flowers from Yucca spp. were collected to estimate and compare the mineral content. Plant samples were collected during the dry and wet seasons of two consecutive years (2006–2007) at seven locations situated in four counties of the state of Durango, Mexico. All macrominerals and trace elements were significantly different among plants within each group of plants. The Ca, Mg, K, Fe and Mn content of most plants were in sufficient amounts to satisfy adult range requirements; however, P, Na, Cu and Zn resulted with marginal deficiencies.

Xylem water potentials of native shrubs from northeastern Mexico

Abstract Xylem water potentials (Ψ) were evaluated in browse plants such as Forestiera angustifolia (Oleaceae), Celtis pallida (Ulmaceae), Zanthoxylum fagara (Rutaceae), and Eysenhardtia texana (Fabaceae). Collections were carried out at Linares County, a semi-arid region of northeastern Mexico. Ψ (MPa) were estimated at 10-day intervals between July 10 and September 30, 2008 by using a Scholander pressure bomb, and were monitored in five different plants per species at 06:00 h (predawn) and 14:00 h (midday). Air temperature, relative humidity, precipitation, and soil water content were registered throughout. Data were subjected to one-way ANOVA and linear correlation analysis. At the wettest period, Ψ at predawn varied from − 0.29 (C. pallida and E. texana) to − 0.37 (F. angustifolia and Z. fagara); in contrast, at the driest period, predawn Ψ ranged from − 3.28 (F. angustifolia) to − 4.50 (Z. fagara). At midday E. texana achieved the highest (−1.14) and lowest (−4.20) values at wettest and driest sampling dates, respectively. It seems that air temperature and vapor pressure deficit negatively influenced Ψ values in all species; conversely, Ψ values augmented as relative humidity increased. Since F. angustifolia and C. pallida maintained higher predawn and midday Ψ values under water stress, these species may be considered as drought-adapted species while, Z. fagara and E. texana that acquired lower values, may be less adapted to drought and in physiological disadvantage under limited water conditions.

Firewood Production, Yield and Quality of Charcoal From Eucalyptus camaldulensis and E. microtheca Planted in the Semiarid Land of Northeast Mexico

Energy production is one the most important topics worldwide. Native forests are good contributors for the production of bioenergy. However, in environmentally difficult conditions, such as arid and semi-arid lands, native trees species produce low woody volume. Alternatives of raw sources from forest plantations of fast growing species, such as eucalyptus, should be analyzed. Firewood production and physical properties of Eucalyptus camaldulensis and E. microtheca on semi-arid land were determined. Yield and quality of charcoal produced at 450, 650, 850, and 1050°C from sapwood and hardwood under laboratory conditions were analyzed. Data were analyzed as random blokes, and ANOVA tests were developed to determine differences in charcoal yield and quality between temperatures and anatomical sections on both species. Eucalyptus microtheca produced higher firewood volume (71.10 m3 ha−1) than E. camaldulensis (19.78 m3 ha−1). Green (1.0 to 1.3 g cm−3), oven-dry (0.8 to 1.1 g cm−3), and basic densities (0.6 to 0.9 g cm−3) showed statistical differences between species and wood type. Statistical differences (p < 0.0001) in the charcoal yield of both species were found; E. microtheca heartwood produced the highest charcoal yield (44%) at a temperature of 450°C. Correlation coefficient between basic density and charcoal yield at all temperatures was high (r = 0.36 to 0.72). Values of moisture content, ash, volatile materials, fixed carbon, and calorific value meet the international standard requirements.

Variability in leaf Traits of 14 Native Woody Species in Semiarid Regions of Northeastern Mexico

The present study was undertaken with the goal of analyzing the morphology and variability of leaf length, width, petiole length, and total leaf length, fresh and dry weight of individual leaves of 14 species native to Northern Mexico. The native species Cordia boissieri, Condalia hookeri, Sargentia greggii, Diospyros texana, Zanthoxylum fagara, Sideroxylon celastrinum, Karwinskia humboldtiana, Celtispallida, Guaiacum angustifolium, Prosopis laevigata, Celtis laevigata, Parkinsoniatexana, Forestiera angustifolia and Havardia pallens where chosen due to their ecological and economic importance to the rural villages as well as large variability in morphological characteristics between them. Descriptive statistical analyses showed that there was large variability in these leaf traits between the different species. Principal component analysis (PCA) revealed that it was possible to produce two axes that can explain more than 83% of the observed variation and could therefore be used in the future for separating tree species in ecological guilds and to study. Species and vegetation community level response to perturbations or individual performance in the field or under experimental conditions between the different species of this study. This suggests that similar advances are possible for other species for the same traits both in the region of study but also elsewhere.

Flower, fruit phenology and flower traits in Cordia boissieri (Boraginaceae) from northeastern Mexico

We characterized variations in Cordia boissieri flowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80% C. boissieri plants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1–4 styles; 2–9 stamens; 6.5–41.5 mm long corolla; sepals from 4.5–29.5 mm in length; a total length from 15.5–59 mm; a corolla diameter from 10.5–77 mm. The nectar guide had a diameter from 5–30.5 mm; 4–9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants.

Seasonal water relations in four co-existing native shrub species from Northeastern Mexico

ABSTRACT Seasonal xylem water potentials (Ψ, MPa) and their relationship to soil water content and evaporative demand components were studied in the shrub species Acacia amentacea, Celtis ehrenbergiana, Forestiera angustifolia, and Parkinsonia texana var. macra. Predawn (Ψpd) and midday (Ψmd) water potentials were estimated at 15 days intervals, between January 15 and October 30, 2009 using a Scholander pressure bomb at 06:00 h (predawn) and 14:00 h (midday), respectively. During the humid period, Ψpd ranged from −0.30 MPa (C. ehrenbergiana), to −0.90 MPa (P. texana). In contrast, over the driest period, Ψpd varied between −2.18 (P. texana) and −3.94 MPa (F. angustifolia). At midday, P. texana and F. angustifolia showed the highest (−1.14 MPa) and lowest (−3.38 MPa) Ψ values, respectively. Average soil water content accounted for 35 to 70% of the variation in predawn Ψ. Furthermore, both Ψ reflected the environmental conditions, as indicated by typical correlations observed. The studied shrub species exhibited what seem to be different strategies to avoid damage caused by drought. Thus, P. texana behaved rather as an isohydric plant able to deal well with severe, but short periods of drought. Under exceptionally dry environmental conditions, Ψpd undercut Ψmd values. Similar observations have been made by researchers studying plants in dry ecosystems. All studied native species are recommended for reforestation of the Tamaulipan shrublands, although C. ehrenbergiana and F. angustifolia seem to have limited tolerances for extreme water stress.

Nutritional value of Acacia amentacea and Parkinsonia texana grown in semiarid conditions

In order to evaluate the nutritional value of Parkinsonia texana and Acacia amentacea, two leguminosae species of the Tamaulipan scrubland, Northeastern Mexico, two experiments were carried out: the first tested the effects of season and browse species on chemical composition as nutritional variable to small ruminants; the second tested the effect of the addition of polyethylene glycol (PEG) on fermentation parameters. Foliage samples were collected from three sites. Data of chemical composition were analysed using analysis of variance for a bi-factorial arrangement, whereas the effect of PEG was analysed by a strip plot design. Results of chemical composition were affected by interacting factors season*species as individually they were significantly different (P<0.001). Addition of PEG affected (P<0.001) fermentation parameters. Significantly higher values of neutral detergent fibre (42%), condensed tannins (19%), purines (9 μmol), partitioning factor (PF) (6.1) and gross energy losses (GEL=6.7%) were found in A. amentacea, while P. texana gave higher crude protein (18%), in vitro true organic matter digestibility (82%), metabolisable energy (ME) [2.1 Mcal/kg dry matter (DM)], A (183 mL), c (0.07/h) and L (0.86 h). Addition of PEG increased ME, and affected (P<0.001) fermentation parameters A and c, while purines and PF decreased. Results indicate that chemical composition and fermentation parameters vary according to seasons and species. PEG addition increases the fermentation parameters, which indicates that PEG counteracts the detrimental effects of secondary components of samples. Data suggest that using both species combined could supply necessary nutritional requirements to small ruminants in the Tamaulipan scrubland.