Abstract
A large area of the terrestrial land surface is used for livestock grazing. Trees on grazing lands provide and can enhance multiple ecosystem services such as provisioning, cultural and ...regulating, that include carbon sequestration. In this study, we assessed the above- and belowground carbon stocks across six different land-uses in livestock-dominated landscapes of Mexico. We measured tree biomass and soil organic carbon (SOC) stocks in fodder banks, live fences, pasturelands with dispersed trees, secondary forests, and primary forests from three different geographical regions and compared them with conventional open pasturelands respectively. We also calculated tree diversity indices for each land-use and their similarity with native primary forests. The aboveground woody biomass stocks differed significantly between land-uses and followed the gradient from less diverse conventional open pasturelands to silvopastoral systems and ecologically complex primary forests. The SOC stocks showed a differential response to the land-use gradient dependent on the study region. Multivariate analyses showed that woody biomass, fine root biomass, and SOC concentrations were positively related, while land-use history and soil bulk density showed an inverse relationship to these variables. Silvopastoral systems and forest remnants stored 27–163% more carbon compared to open pasturelands. Our results demonstrate the importance of promoting appropriate silvopastoral systems and conserving forest remnants within livestock-dominated landscapes as a land-based carbon mitigation strategy. Furthermore, our findings also have important implications to help better manage livestock-dominated landscapes and minimize pressures on natural protected areas and biodiversity in the hotspots of deforestation for grassland expansion.
Owing to the increasing extension of land for livestock production, silvopastoral practices have been among the promising approaches to enhance carbon (C) sequestration. However, the extent of C ...sequestration in different silvopastoral systems (SPS) and their relationship with fine root production (FRP) is not well understood. The objective of this research was to evaluate the changes in C storage, FRP, and turnover in a part of tropical SPS. We evaluated above‐ and belowground C storage, FRP and turnover in live fences (LF), dispersed tree (DT) silvopasture, and compared these with open pasturelands (OP) in Southeastern Mexico. We applied the stock change approach to calculate biomass growth rates and the ingrowth monolith method for FRP. Biomass stocks in the same plots are re‐measured over time in the stock change approach. Woody biomass stocks differed significantly between SPS (DT: 37.2, LF: 9.8 Mg ha−1) and the accumulation rates in both SPS were significantly higher than zero (0.2–2.2 Mg ha−1 yr−1). Soil organic carbon (SOC) contents were significantly higher in SPS (LF: 2.4%, DT: 3.1%) compared to OP (1.6%). FRP significantly differed between SPS (LF: 27.8, DT: 45.4, and OP: 9.4 g m−2 yr−1) and correlated positively with SOC content. Higher SOC reduced soil compaction in silvopastoral lands as indicated by lower soil bulk density. The results on C stocks change and fine root dynamics contribute to understanding C sequestration potential of tropical SPS, identifying ecologically sound strategies to mitigate greenhouse gases from the livestock sector, and aid restoration of ecosystem services for degraded pasturelands.
The sustainability of family farms, or Family Production Units (FPUs), cultivating native maize varieties in Chiapas, Mexico, is intricately linked to economic, socio-productive, environmental, and ...cultural factors. Given their significance within the regional socio-productive framework, the objective of this study was to assess sustainability across environmental, social, and economic dimensions. The methodology employed for sustainability analysis was the Framework for Evaluation of Natural Resource Management Systems (MESMIS). Thirty FPUs were purposively selected from 14 communities spanning four municipalities and were typologically classified into three groups: Traditional, Maize Growers-Livestockers, and Diversified. In-depth interviews were conducted with individual farmers, complemented by group interviews involving entire families. The collected data underwent processing through multiple correspondence statistical analysis, analysis of variance for linear models, and multiple comparisons of means. The results indicated that the Diversified FPU group exhibited higher sustainability, covering 68% of the sustainability perimeter. Consequently, this group demonstrated better conditions for preserving native maize varieties over time and developing strategies to meet their needs concurrently. The Traditional FPU group covered 58%, while the Maize Growers-Livestockers group covered 52% of the sustainability perimeter. In conclusion, it was observed that family reproduction strategies, grounded in resource utilization (capitals), shape forms of nature appropriation that are continually reconfigured. These configurations play a pivotal role in defining the sustainability of FPUs engaged in native maize cultivation in the Frailesca region.
ABSTRACT The objective of this study was to evaluate the productive performance, apparent digestibility, and carcass and longissimus dorsi muscle characteristics of lambs fed diets supplemented with ...four levels of Saccharomyces cerevisiae. Thirty-two male Hampshire lambs (25.82±1.95 kg body weight) were distributed in four treatments: basal diet (20:80, forage:concentrate), and the inclusion of 0, 3, 5, and 10 g animal−1 d−1Saccharomyces cerevisiae. The variables evaluated were dry matter intake, daily weight gain, feed conversion, apparent digestibility, dorsal fat thickness, longissimus dorsi muscle area, and physicochemical characteristics of carcass and muscle. We used a completely randomized design and orthogonal polynomials to test the linear and quadratic effects of the inclusion levels of the yeast. Saccharomyces cerevisiae showed a quadratic effect on lamb performance. Dry matter intake decreased with yeast in response to a better feed conversion and body weight gain; however, at the highest Saccharomyces cerevisiae dose, daily weight gain and final weight were lower than with the basal diet treatment. Saccharomyces cerevisiae did not affect apparent digestibility or carcass and muscle physicochemical characteristics. Supplementation with 3 and 5 g d−1 Saccharomyces cerevisiae improves productive performance of lambs fed high concentrate diets without affecting the physicochemical characteristics of the carcass or muscle.
Agroforestry practices that include trees on grazing lands could enhance atmospheric CO
2
sequestration and storage. However, carbon sequestration rates and storage capacity of intensively grazed ...agroforestry systems vary due to the diversity in species composition, stand structure, system age, and management practices. The objective of this study was to evaluate carbon stocks and accrual rates in
Leucaena leucocephala
+
Cynadon plectostachyus,
and
Brachiaria decumbens
grass silvopastoral systems and compare them with conventional open grazing lands. The study was carried out in Chiapas in southern Mexico, one of the hotspots of deforestation driven by the expansion of livestock farming. We measured above- and belowground carbon stocks in 18 silvopasture (SP) plots, with the plantation age ranging from 2 to 10 years. Nine plots of adjacent conventional full-sun grasslands (open pasturelands) grazed rotationally were sampled for comparison. The average tree biomass stock in SP was 5.5 ± 1.9 Mg C ha
−1
and differed with SP age. Mean annual biomass accrual rates ranged from 0.25 to 2.57 Mg C ha
−1
year
−1
, indicating that SP systems are CO
2
sinks, excluding other sources of GHG such as methane emissions from enteric fermentation. The average soil organic carbon (SOC) sequestration rate of SP was 0.143 ± 0.043 Mg C ha
−1
year
−1
to 50 cm depth. The SOC sequestration rates correlated positively with SP age at the beginning and decreased after about 8 years. The results suggested that the age and lifespan of trees play a significant role in aboveground C sequestration through the
Leucaena leucocephala
SP, while SOC storage varied with soil properties. Further research on the relative response of active and stable SOC fractions along with soil CO
2
fluxes could explain the results on the SOC storage potential of these agroforestry systems.
This experiment was designed to evaluate the effects of Agave tequilana inulin and Lactobacillus casei (L. casei) on growth performace, hematological variables, serum metabolites, and total coliforms ...in nursing lambs.
The experimental design was completely randomized; treatments were T1, control (pre-starter concentrate, PC), T2: T1+2% inulin, and T3: T1+2% inulin+L. casei; treatments were compared with Tukey test (p≤0.05); and 45 new born Kathadin×Dorset lambs (4.8±0.8 kg birth weight) were the experimental units (15 per treatment). The variables were daily weight gain (DWG), dry matter intake and diarrheas incidence (%) during 56 d. Twenty-four hours after birth and at the end of the experiment, blood samples were collected to evaluate hematological variables and serum metabolites. Besides, the populations of total coliforms and lactobacilli were estimated in fecal samples.
Addition of agave inulin and L. casei increased (p≤0.05) DWG 356, 384, and 415 g/d, weaning weight 24.92, 26.18, and 28.07 kg, as well as lactobacilli population 5.79, 6.32, and 6.48 Log10 cfu/g, for T1, T2, and T3, respectively. Lambs fed L. casei had decreased (p≤0.05) populations of total coliforms (T1 = 6.18, T2 = 5.77, and T3 = 5.07 Log10 cfu/g), diarrheas incidence (T1 = 11.67%, T2 = 8.33%, and T3 = 5.0%), and serum cholesterol concentration (11% in T2 and 13% in T3, compared to control).
The combination of Agave tequilana inulin and L. casei increases weight gain and improves intestinal health by reducing coliforms and diarrheas incidence in Katahdin× Dorset lambs during the pre-weaning period.
Fire has been an integral part of ecosystem functioning in many biomes for a long time, but the increased intensity and frequency of wildfires often affect plant diversity and carbon storage. ...Prescribed burning is one of the alternatives to forest fuel management where the fire is controlled and carried out under a determined set of weather conditions and objectives. The effect of prescribed burning on plant diversity and carbon (C) storage has not been studied widely. The objective of this study was to evaluate the effect of prescribed burning on plant diversity indices, biomass stocks, and soil C storage in the tropical highland forests of Southern Mexico. We assessed plant diversity and carbon stocks at 21 sampling sites: seven with prescribed burning, seven non-burning, and seven with wildfires. We calculated tree biodiversity indices, stand structural properties, and species composition among burning treatments. We quantified C stocks in vegetation biomass by using an allometric equation and forest litter by direct sampling. We analyzed 252 soil samples for soil organic C content and other properties. The results showed that the biodiversity index was higher in sites with prescribed burning (Shannon index, H = 1.26) and non-burning (H = 1.14) than in wildfire sites (H = 0.36). There was a greater similarity in plant species composition between non-burning and prescribed burning sites compared to wildfire sites. Prescribed burning showed a positive effect on soil carbon storage (183.9 Mg C ha−1) when compared to wildfire (144.3 Mg C ha−1), but the difference was not statistically significant (p > 0.05) in biomass stocks. Prescribed burning in this study conserved plant diversity as well as soil carbon stocks compared to non-burning, the opposite of what we found in wildfires.
Objective. To determine the recommended dose of bentonite as a chelator of arsenic (As) and lead (Pb) in the rumen, abomasal and duodenal environment by means of an in vitro system, considering the ...variables of ruminal fermentation and the adsorbent effect of As and Pb. Materials and Methods. Vials were prepared with 50 mL of anaerobic medium and 0.5 g of alfalfa as substrate. The culture media were added with 1.01 and 1.95 ppm of As and Pb, respectively. The treatments consisted of different levels of bentonite (B) added to the medium, B-0%, B-1.5%, B-3.0% and B-4.5%. The media were incubated for 24 h, and pH, volatile fatty acid (VFA) and N-NH3 production, in vitro DM digestibility (IVDMD) and chelating effect of bentonite were measured, simulating rumen, abomasum and duodenum conditions. A completely randomised design and orthogonal contrasts were used. Results. Bentonite did not modify the pH (p > 0.05) and the molar proportion of VFAs, but the total VFA concentration presented a negative linear effect with increasing bentonite levels. Likewise, the N-NH3 level decreased (p < 0.05) with increasing inclusion levels of bentonite. The IVDMD was reduced with B-3% and B-4.5% (52.36b and 49.74b%) in comparison to B-0% and B-1.5% (62.30a and 61.98a%). Treatments B-1.5% and B-4.5% improved (p < 0.05) As and Pb adsorption in the rumen, abomasal and duodenal environments. Conclusions. The recommended level of bentonite as chelator of As and Pb is 1.5%; doses of 4.5% affect IVDMD and, consequently, animal productivity.
Objetivo. Determinar la dosis recomendable de bentonita como quelante de arsénico (As) y plomo (Pb) en el medio ruminal, abomasal y duodenal mediante un sistema in vitro, considerando las variables de fermentación ruminal y el efecto adsorbente de As y Pb. Materiales y Métodos. Se prepararon viales con 50 mL de medio anaerobio y 0.5 g de alfalfa como sustrato. Los medios se adicionaron con 1.01 y 1.95 ppm de As y Pb, respectivamente. Los tratamientos consistieron en el nivel de bentonita (B) adicionada al medio, B-0%, B-1.5%, B-3.0% y B-4.5%. Los medios se incubaron durante 24 h y se midió el pH, producción de AGV, N-NH3, degradabilidad in vitro de MS (DIVMS) y efecto quelante de la bentonita, simulando las condiciones del rumen, abomaso y duodeno. Se usó un diseño completamente al azar y contrastes ortogonales. Resultados. La bentonita no modificó el pH ni la proporción molar de AGV (p>0.05), pero la producción total de AGV presentó un efecto lineal negativo al aumentar el nivel del mineral. Asimismo, el N-NH3 disminuyó (p<0.05) al adicionar bentonita. La DIVMS fue menor con B-3.0% y B-4.5% (52.36b y 49.74b%) en comparación con B-0% y B-1.5% (62.30a, 61.98ª). La inclusión de B-1.5% y B-4.5% mejoró (p<0.05) la adsorción de As y Pb en el medio ruminal, abomasal y duodenal. Conclusiones. La proporción de bentonita recomendable como quelante de As y Pb es de 1.5%, ya que la dosis de 4.5% afectan la DIVMS y por consiguiente, la productividad animal.
El objetivo fue evaluar modelos predictivos de la producción metano de los frutos Leucaena collinsii y Guazuma ulmifolia medido a través de la técnica de producción de gas in vitro (TPG) y ...cromatografía de gases. A los frutos se realizó un análisis químico, parámetros de fermentación in vitro, y se estimó metano por cromatografía de gases y por la TPG. Se realizó un análisis de varianza considerando los efectos fijos de la técnica de medición y el tipo de fruto. Se hizo un análisis de correlación y regresión para conocer las ecuaciones y los coeficientes de determinación entre CH4 por cromatografía de gases y estimación de CH4 a partir de la TPG. Se encontró una tendencia positiva entre la estimación de metano por cromatografía de gases y por la TPG, por lo que, la TPG es promisoria para la determinación de metano de frutos de Leucaena collinsii y Guazuma ulmifolia.
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