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Inga jinicuil is used extensively in shade coffee farms in Mexico, a diversified agroforestry system providing important environmental goods and services. However, its recalcitrant seeds represent an important barrier to its propagation. Given the climate change scenarios, it will be necessary to generate information on the effect of temperature on germination, a key stage for the establishment and conservation of the species. The objective of the study was to determine the optimal germination temperatures for I. jinicuil using linear and non-linear models, as well as the species’ potential distribution under contrasting climate change scenarios using the GISS-E2-1-G model. Seeds were placed in germination chambers at constant temperatures of 5 ± 0.5 to 40 ± 0.5 °C, and their thermal responses were then modelled using a thermal timing approach. Results indicated a good fit of models of I. jinicuil germination in response to temperature. Seeds germinated across a wide temperature range; the base temperature for germination was in the range of 4.8 to 9.45 °C (average T b : 6.21 ± 2.23 °C). and the ceiling temperature in the range of 44.51 to 49.20 °C (average T c : 47.6 ± 2.73 °C). While the optimal temperature was found in the range of 29.58 to 33.02 °C (average T o : 31.52 ± 1.43 °C). The suboptimal thermal time ( 1 (50)) for germination of 50% of the seed lot was 117.164 ± 0.636°Cd, which under current climatic conditions is reached in 6.6 days. According to climate modeling, the distribution of I. jinicuil populations will decrease by up to 23% in the future relative to the current distribution. Results indicate that high temperatures have a negative effect on germination, which may be related to seed physiology. More research on seed germination and growth is needed to improve the management and conservation of this species and its continued use as a shade tree in coffee agroforestry systems.

Agroforestry systems with native vegetation enhance climate adaptation and mitigation by improving coffee farm resilience, carbon storage, and income diversification. Seven native tree species were pre-selected as shade providers for Veracruz coffee agroforestry systems based on ecological, cultural, and economic criteria. The present study evaluated their physiological performance through above-ground biomass, carbon stocks, and in-situ chlorophyll fluorescence and gas exchange measurements under controlled light and temperature conditions. Five Coffea arabica varieties were also assessed under these shade canopies using the same leaf-level parameters, and leaf nitrogen and moisture content. Erythrina americana and Persea schiedeana had the highest carbon sequestration per tree. E. americana showed the highest water-use efficiency, whereas P. schiedeana showed the lowest transpiration and stomatal conductance, indicating a water-saving strategy via stomatal restriction. These traits reflect their ecological adaptations to shade and microclimate conditions in agroforestry systems. Inga inicuil achieved the highest carbon capture per hectare due to high tree density, despite lower individual performance. Species-specific strategies were identified: Psidium guajava and P. schiedeana exhibited high transpiration but limited carbon gain. E. americana and Inga punctata formed a drought-resilient group, having a high carbon assimilation and low water loss. Intermediate species ( Heliocarpus appendiculatus , Inga vera , I. inicuil ) balanced moderate CO 2 assimilation rates with adaptable stomatal response. Photochemical efficiency remained stable across species. Shaded Coffea arabica var. Oro Azteca had significantly higher leaf nitrogen, moisture, and water-use efficiency than unshaded ones. These differences coincided with lower PAR under shade, aligning with known variations in shaded versus unshaded coffee plants. Principal component analysis showed that PC1 correlated strongly with stomatal conductance and transpiration, driven by P. guajava and P. schiedeana . PC2 showed a carbon economy trade-off between CO 2 assimilation and internal concentration, dominated by E. americana . Collectively, these components highlight stomatal regulation and carbon management as adaptive strategies. Coffee PCA revealed contrasting water-use strategies: PC1 showed inverse stomatal regulation (especially in shaded varieties), and PC2 an energy allocation trade-off between photochemical efficiency and carbon assimilation, with shaded plants maintaining stable CO 2 assimilation regarding unshaded ones. These results demonstrate notable interspecific variation in carbon storage, water-use efficiency, and light conditions among shade trees, offering empirical support for species selection in Veracruz coffee agroforestry.

The temperature reduces the viability and seed vigor; however, the effect of temperature on imbibition and fatty acid profile has not been studied. Chia (Salvia hispanica L.) seeds have a substantial quantity of oil, making them a potential study model for fatty acid metabolism. Therefore, we explore the effect of temperature (10, 20, and 30 °C) on chia seed imbibition, germination, and fatty acid profile by GC-MS. Imbibition FI occurs within the first hour in all the treatments; while FII and FIIend elapse with an hour of difference at 20 °C and 30 °C. The highest viability and germination rate were observed at 30 °C; while the highest concentrations of all fatty acids, except oleic acid, were observed at 20 °C. Maximum fatty acid concentrations were detected at FI and FIIend; while at 30 °C, different patterns for saturated and unsaturated fatty acids and three linolenic acid isomers were observed. A shorter FII is associated with earlier germination; the increase in concentration in fatty acids after 3 h and a negative correlation between linoleic and linolenic acid observed at 20 °C were related to a higher germination efficiency. At 30 °C, isomer formation is related to homeoviscous cell membrane adaptation.

Temperature is the main factor that impacts germination and therefore the success of annual crops, such as chia (Salvia hispanica L.), whose seeds are known for their high nutritional value related to its oil. The effect of temperature on germination is related to cardinal-temperature concepts that describe the range of temperature over which seeds of a particular species can germinate. Therefore, in this study, in addition to calculated germinative parameters such as total germination and germination rate of S. hispanica seeds, the effectiveness of non-linear models for estimating the cardinal temperatures of chia seeds was also determined. We observed that germination of S. hispanica occurred in cold to moderate-high temperatures (10–35 °C), having an optimal range between 25 and 35 °C, with the highest GR and t50 at 30 °C. Temperatures higher than 35 °C significantly reduced germination. Output parameters of the different non-linear models showed that the response of chia germination to temperature was best explained by beta models (B). Cardinal temperatures calculated by the B1 model for chia germination were: 2.52 ± 6.82 °C for the base, 30.45 ± 0.32 °C for the optimum, and 48.58 ± 2.93 °C for the ceiling temperature.

Climate change models predict temperature increases, which may affect germination, an important stage in the recruitment of individuals in agroecosystems. Therefore, it is crucial to conduct research on how temperature will impact the germination of multipurpose native species. Leucaena diversifolia (Schltdl.) Benth. is native to America and is commonly cultivated around the world due to having a high protein content in seeds, and their trees are used in agrosilvopastoral systems because they fix nitrogen and provide shade and cattle feed. However, climate change affects the critical phases of its life cycle and influences its growth, reproduction, phenology, and distribution. To assess the germination performance of Leucaena diversifolia under different temperatures throughout thermal times, we estimated germination variables and determined cardinal temperatures and thermal time; we also analysed germination and potential distribution under two climate change scenarios. We found significant variations in seed germination (78–98%) and differences in cardinal temperatures (Tb = 5.17 and 7.6 °C, To = 29.42 and 29.54 °C, and Tc = 39.45 and 39.76 °C). On the other hand, the sub-optimal and supra-optimal temperature values showed little differences: 51.34 and 55.57 °Cd. The models used showed variations in germination time for the analysed scenarios and the potential distribution. We confirm that the populations and distribution of L. diversifolia will be altered due to climate changes, but the species retains the ability to germinate under warmer conditions.

Swietenia macrophylla is an economically important tree species propagated by seeds that lose their viability in a short time, making seed germination a key stage for the species recruitment. The objective of this study was to determine the cardinal temperatures and thermal time for seed germination of S. macrophylla; and its potential distribution under different climate change scenarios. Seeds were placed in germination chambers at constant temperatures from 5 to 45 °C and their thermal responses modelled using a thermal time approach. In addition, the potential biogeographic distribution was projected according to the Community Climate System Model version 4 (CCSM4). Germination rate reached its maximum at 37.3 ± 1.3 °C (To); seed germination decreased to near zero at 52.7 ± 2.2 °C (ceiling temperature, Tc) and at 12.8 ± 2.4 °C (base temperature, Tb). The suboptimal thermal time θ150 needed for 50% germination was ca. 190 °Cd, which in the current scenario is accumulated in 20 days. The CCSM4 model estimates an increase of the potential distribution of the species of 12.3 to 18.3% compared to the current scenario. The temperature had an important effect on the physiological processes of the seeds. With the increase in temperature, the thermal needs for germination are completed in less time, so the species will not be affected in its distribution. Although the distribution of the species may not be affected, it is crucial to generate sustainable management strategies to ensure its long-term conservation.

Cedrela odorata is a native tree of economic importance, as its wood is highly demanded in the international market. In this work, the current and future distributions of C. odorata in Mexico under climate change scenarios were analyzed according to their optimal temperature ranges for seed germination. For the present distribution, 256 localities of the species’ presence were obtained from the Global Biodiversity Information Facility (GBIF) database and modelled with MaxEnt. For the potential distribution, the National Center for Atmospheric Research model (CCSM4) was used under conservative and drastic scenarios (RCP2.6 and RCP8.5 Watts/m2, respectively) for the intermediate future (2050) and far future (2070). Potential distribution models were built from occurrence data within the optimum germination temperature range of the species. The potential distribution expanded by 5 and 7.8% in the intermediate and far future, respectively, compared with the current distribution. With the increase in temperature, adequate environmental conditions for the species distribution should be met in the central Mexican state of Guanajuato. The states of Chihuahua, Mexico, Morelos, Guerrero, and Durango presented a negative trend in potential distribution. Additionally, in the far future, the state of Chihuahua it is likely to not have adequate conditions for the presence of the species. For the prediction of the models, the precipitation variable during the driest month presented the greatest contribution. When the humidity is not limiting, the thermal climatic variables are the most important ones. Models based on its thermal niche for seed germination allowed for the identification of areas where temperature will positively affect seed germination, which will help maximize the establishment of plant populations and adaptation to different climate change scenarios.

Background: Breastfeeding (BF) improves food security (FS) in underprivileged and Indigenous communities and strongly correlates with midwifery practice. This paper examines the generational history of breastfeeding in the resilient and culturally diverse Mazahua Otomi (MO) community and its relationship to midwifery, traditional herbalism, and food security. Research Aim: To analyze the time of generational breastfeeding (BF) and relate it to midwifery, traditional herbalism, and food security. Methods: A structured survey, conducted under the esteemed auspices of the Intercultural University of the State of Mexico (UIEM), was administered to the students, their mothers, and their paternal and maternal grandmothers, ensuring the reliability and quality of the data collected. Results: In three generations, the lactation period has been 13.73 months, which is above the national average and has remained constant. Births by midwives have decreased at a rate of 35%, and there is a surplus of 16% more births by midwives compared to the mestizo community. 55% of the MO community perceive that through BF, there is a saving to the family economy of between 50% and 100%. Conclusion: This study's findings underscore the substantial contribution of MO's breastfeeding practices, midwifery, and use of medicinal plants to FS in the first 13 months of infants' lives. This is particularly significant regarding the accessibility of food and herbal resources, providing crucial insights for future research and policy development.

Pinus ayacahuite is an important species for reforestation in Mexico, as it is a pioneer species in open areas. Its regeneration could be threatened by rising temperatures. The effect of a temperature gradient on germination was analyzed, and potential distribution projections of climate change scenarios were modeled at various time scales. Seeds were collected in Huayacocotla, Veracruz; these were germinated under nine constant temperatures (5–45 °C). Germination parameters, cardinal temperatures, and thermal time were estimated using a Gaussian model. Germination occurred between 10 and 40 °C, with optimal, base, and ceiling temperatures of 27 °C, 10 °C, and 42 °C, respectively, and a thermal time (Tt[sub.50]) of 118.5 °C d[sup.−1]. Based on climate change projections (SSP1-2.6 and SSP5-8.5), NASA’s GISS-E2-1-G model predicts temperature increases from 1.1 to 2.3 °C by 2050 and from 1.7 to 3.6 °C by 2090, which would accelerate germination by 12.9–25 days. However, the species’ potential distribution is projected to decline by 15%–22%, primarily in southern states such as Chiapas, Oaxaca, and Puebla, although it could shift to new suitable areas in Tamaulipas and Nuevo León. These results suggest that while higher temperatures may favor earlier germination, water availability will remain the main limiting factor for successful establishment. Integrating physiological parameters into distribution models offers a stronger foundation for seed storage, conservation, and reforestation strategies in the face of changing climatic conditions.

Thermal time models are useful to determine the thermal and temporal requirements for seed germination. This information may be used as a criterion for species distribution in projected scenarios of climate change, especially in threatened species like red cedar. The objectives of this work were to determine the cardinal temperatures and thermal time for seeds of Cedrela odorata and to predict the effect of increasing temperature in two scenarios of climate change. Seeds were placed in germination chambers at constant temperatures ranging from 5 ± 2 to 45 ± 2 °C. Germination rate was analyzed in order to calculate cardinal temperatures and thermal time. The time required for germination of 50% of population was estimated for the current climate, as well as under the A2 and B2 scenarios for the year 2050. The results showed that base, optimal and maximal temperatures were −0.5 ± 0.09, 38 ± 1.6 and 53.3 ± 2.1 °C, respectively. Thermal time (θ1(50)) was 132.74 ± 2.60 °Cd, which in the current climate scenario accumulates after 5.5 days. Under the A2 scenario using the English model, this time is shortened to 4.5 days, while under scenario B2, the time is only 10 hours shorter than the current scenario. Under the German model, the accumulation of thermal time occurs 10 and 6.5 hours sooner than in the current climate under the A2 and B2 models, respectively. The seeds showed a wide range of temperatures for germination, and according to the climate change scenarios, the thermal time accumulates over a shorter period, accelerating the germination of seeds in the understory. This is the first report of a threshold model for C. odorata, one of the most important forest species in tropical environments.