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 CO2 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 CO2 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 CO2 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.

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 (Tt50) of 118.5 °C d−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.

Agroforestry systems, such as shade-grown coffee plantations are particularly well suited to address the challenges of climate change, due to potential synergies between adaptation and mitigation strategies. The traditional knowledge of coffee producers can play a critical role in optimizing agroforestry approaches and shade tree selection to balance biodiversity conservation and local needs. This knowledge was used in a two-stage hybrid methodology identifying the shade tree species that help coffee growers in central Veracruz, México, face multiple challenges including climate change, biodiversity conservation, and improved livelihoods. Multi-criteria decision analysis using the distribution and conservation traits and agroecological information available of the native tree species of Veracruz, helped generate a preliminary list of 50 prioritised species, which was refined by incorporating local knowledge of each species in participatory workshops involving smallholder producers, where gender equality and social inclusion principles were applied. Species with the highest priority score were those belonging to the genus Inga (I. jinicuil, I. vera, I. punctata), which provides shade, soil fertility, bird habitat, and food. Domesticated species of the genera Persea (P. americana, P. schiedeana, P. longipes) and Psidium (P. guajava), were also prioritised as they are considered as important elements for shade and fruit production. This methodology combines distribution and conservation and ecological traits with local knowledge to prioritise native tree species for use in shade-grown coffee plantations in the central region of Veracruz. This multidisciplinary approach could be replicated more broadly in México and other coffee growing regions.

Cucurbita argyrosperma Huber ssp. argyrosperma. Cucurbita argyrosperma Huber; Cucurbita moschata argyrosperma Naudin; Cucurbita mixta Pang.; Cucurbita mixta Pang. var. cyanoperizona Pang.; Cucurbita mixta Pang. var. stenosperma Pang.; Cucurbita mixta Pang. gr. var cyanoperizona (Pang.) Zhit.; Cucurbita mixta Pang. gr. var. stenosperma (Pang.) Zhit.; Cucurbita argyrosperma Hort. ex L.H. Bailey; Cucurbita argyrosperma Huber ssp. argyrosperma var. argyrosperma sensu Merrick and Bates; Cucurbita argyrosperma Huber ssp. argyrosperma var. stenosperma (Pang.) Merrick and Bates; and Cucurbita argyrosperma Huber ssp. argyrosperma var. callicarpa Merrick and Bates

In drylands, as far as we know, the impact of subsistence activities such as rainfed agriculture and firewood extraction on the soil seed bank is unknown. In a tropical dryland of central Mexico, rainfed agriculture and firewood extraction resulted in abandoned croplands and mesquite shrublands, respectively. Our aim was to evaluate the species richness, density, and composition of the soil seed bank in abandoned croplands and mesquite shrublands. Species richness and seed density were evaluated in soil samples taken from open spaces and under shrubs in abandoned croplands and mesquite shrublands during the dry season. Seeds were identified and grouped into grasses, weeds, and native plants. The species richness and seed density were similar between the soil bank of abandoned croplands and mesquite shrublands. The soil seed bank in abandoned croplands was dominated by weeds and grasses, whereas in mesquite shrublands was dominated by weeds and native plants. The soil seed bank was relatively similar between the rainfed agriculture and firewood extraction. These results suggest that rainfed agriculture and firewood extraction promote similar changes in the soil seed bank of this tropical dryland, despite being very different subsistence activities.

A substantially rich diversity of the world's recorded useful plants (UPs) is captured within the Millennium Seed Bank collection hosted by the Royal Botanic Gardens, Kew, at Wakehurst, UK with 13,598 species (34%) belonging to 3696 genera and 325 families. This constitutes just over half of the total accessions and one third of the species and covers all 9 continents, 8 realms, 14 biomes, 34 biodiversity hotspots and 175 countries. The most common beneficial use category within the captured diversity is medicinal, then species with environmental, material, and human food value. About 86% of conserved UP species have a 'Least Concern' conservation status but 8% are identified as globally threatened. The advantages of mutual, continued, and long-term partnership (e.g., Mexico) are showcased when conserving plants important for local communities and addressing conservation challenges beyond seed banking. However, the geographic coverage suffers from a lack of partnerships with some parts of the world. Also, a low number of accessions contributed from many countries means that insufficient native range is yet to be captured for many species. This is particularly the case for restricted or narrow distribution species from families or genera with a high incidence of recalcitrant or short-lived seeds. Future planning must tailor better to cover the spatial distribution patterns for individual species, thereby improving the number of accessions and geographical coverage for those captured. Moreover, seed biology research should characterise desiccation tolerance and develop complementary, novel conservation methods, such as cryopreservation, to strengthen conservation options for UP species.

Sechium compositum (J.D. Smith) C. Jeffrey: Microsechium compositum J.D. Smith

Twenty-one years have elapsed of the 21st Century and within the framework of the celebration of the 100th volume of Botanical Sciences, it is relevant to assess the progress of the research on conservation and on the activities undertaken for protecting the plants of Mexico, including the complementary in situ and ex situ approaches. By means of a systematic search of scientific articles related to the conservation of the Mexican flora on the Web of Science database, for the 2000–2021 period, we identified different scientific inputs, all showing specific objectives for undertaking conservation activities. The publications that resulted from this search were classified into six categories: (a) Regions and Ecoregions; (b) Communities or Ecosystems; (c) Taxonomic Groups; (d) Species and Populations; (e) Botanical Gardens; and (f) Seed Banks. For these categories, the results are presented under the headings “in situ conservation” and “ex situ conservation.” Additionally, we assessed by a random examination, the bibliography used to support touristic development projects. The results show that, despite the wide temporal range considered in this review, and even though there is a vast number of publications related to the characterization of the Mexican biodiversity, the production of scientific work oriented to the development of plant conservation strategies and activities is still scarce. Also evident is the lack of connection and communication among researchers of different disciplines, highlighting the disciplinary or multidisciplinary activities that they undertake. Finally, ten conclusions are presented, and some future research activities are suggested for conserving the Mexican flora.

It is well known that bruchids and legumes generally have ecological relationships, such as parasitism and predation; however, little is known about the effects of such relationships on the initial life cycle stages of wild legumes. This study evaluates the effect of Stator pruininus infestation on the germination and early growth of Acacia berlandieri. Germination tests were performed under controlled conditions on healthy seeds, seeds with physical scarification, chemical scarification, damage from larvae, and seeds with eggs. A one-way analysis of variance was used to analyze the germination of seeds (percentage, rate, and mean germination time), as well as the early growth of the seedlings (survival, size, and biomass). The percentage of germination in all of the seed categories was greater than 85%, with significant differences (p < 0.05) between seed categories. However, there were no significant differences between seed categories in germination rate or average germination time (p > 0.05). In the early growth of the seedlings, there were significant differences (p < 0.001) between seed categories in the size of the seedling, stem, and root, and in the aboveground and belowground biomass. Based on these results, S. pruininus is not a predator of A. berlandieri, but the damage done to the cotyledons by this insect species can reduce seedling growth and accumulation of biomass in the first days of growth.

Twenty-one years have elapsed of the 21 st Century and within the framework of the celebration of the 100 th volume of Botanical Sciences , it is relevant to assess the progress of the research on conservation and on the activities undertaken for protecting the plants of Mexico, including the complementary in situ and ex situ approaches. By means of a systematic search of scientific articles related to the conservation of the Mexican flora on the Web of Science database , for the 2000–2021 period, we identified different scientific inputs, all showing specific objectives for un dertaking conservation activities. The publications that resulted from this search were classified into six categories: (a) Regions and Ecoregions; (b) Communities or Ecosystems; (c) Taxonomic Groups; (d) Species and Populations; (e) Botanical Gardens; and (f) Seed Banks. For these categories, the results are presented under the headings “ in situ conservation” and “ ex situ conservation.” Additionally, we assessed by a random examination, the bibliography used to support touristic development projects. The results show that, despite the wide temporal range considered in this review, and even though there is a vast number of publications related to the characterization of the Mexican biodiversity, the production of scientific work oriented to the development of plant conservation strategies and activities is still scarce. Also evident is the lack of connection and communication among researchers of different disciplines, highlighting the disciplinary or multidisciplinary activities that they undertake. Finally, ten conclusions are presented, and some future research activities are suggested for conserving the Mexican flora.

Background Mexico is one of the most floristically rich countries in the world. Despite significant contributions made on the understanding of its unique flora, the knowledge on its diversity, geographic distribution and human uses, is still largely fragmented. Unfortunately, deforestation is heavily impacting this country and native tree species are under threat. The loss of trees has a direct impact on vital ecosystem services, affecting the natural capital of Mexico and people’s livelihoods. Given the importance of trees in Mexico for many aspects of human well-being, it is critical to have a more complete understanding of their diversity, distribution, traditional uses and conservation status. We aimed to produce the most comprehensive database and catalogue on native trees of Mexico by filling those gaps, to support their in situ and ex situ conservation, promote their sustainable use, and inform reforestation and livelihoods programmes. Methods A database with all the tree species reported for Mexico was prepared by compiling information from herbaria and reviewing the available floras. Species names were reconciled and various specialised sources were used to extract additional species information, i.e. endemic status, threat status, availability in seed collections, reports on plant uses and conservation actions currently in place. With this information, a comprehensive catalogue of native trees from Mexico was redacted. Available georeferenced records were used to map each species distribution and perform spatial analyses to identify gaps of information and priority areas for their conservation and exploration. Results Mexico has at least 2,885 native tree species, belonging to 612 genera and 128 families. Fabaceae is the most represented family and Quercus the most represented genus. Approximately 44% of tree species are endemic to the country. The southern part of the country showed the highest values of species richness. Six hundred and seventy-four species have at least one documented human use. In terms of conservation assessment, ca. 33% of species have been assessed by either the IUCN Red List (919) or the National protection catalogue “NORMA Oficial Mexicana NOM-059” (29) or both (45). Additionally, 98 species have been included in the CITES listing for protection. In terms of existing conservation efforts, 19% of species have ex situ protection in seed banks, while protected areas overlap with all the identified peaks of species richness, except for those in the states of Veracruz and Chiapas. This work constitutes a key milestone for the knowledge, management, and conservation of the Mexican native trees. The two areas with high density of tree species identified in Veracruz and Chiapas represent two priority areas for tree conservation in Mexico, where integrated in situ and ex situ conservation efforts should be focused.

The efficient storage and germination of seeds underpin the effective use of plants for livelihoods and sustainable development. A total of 204 wild species useful for local communities of the Tehuacán–Cuicatlán Valley were collected and stored in seed banks in country for long term conservation, and 66 % (i.e., 134) duplicated in the U.K., as an effective means of ex situ conservation. Of the 204 species, 147 (122 of which also duplicated in the U.K.) were previously listed as useful plants in the ethnofloristic inventory of the Valley. Based on literature surveys, we found that one of the major impediments to the use of stored seeds of wild species is the lack of knowledge of how to germinate the seed. In detailed studies, we found that seeds of 18 useful plant species from 10 different families germinated readily and could be propagated. In contrast, four species (Actinocheita filicina, Bursera submoniliformis, Karwinskia mollis and Lippia graveolens) produced dormant seeds and therefore further studies are needed before their use can be maximised in large scale propagation programmes in support of conservation and livelihoods. Overall, this large-scale study on useful wild plant species in Mexico confirms that conventional seed banking can effectively support sustainable development and livelihood programmes.

In this chapter, the importance of ex situ conservation is discussed to safeguard plant genetic resources on relationship to its ethnobotanical relevance. It also highlights the importance of preserving the germplasm of species that are closely associated to human being. The diverse forms and intensities of human–plant relationship lead to the accumulation of traditional knowledge and the modification of the characteristics of plant populations as a result of human manipulation. When the germplasm of plant populations that are important to human being is protected, the information associated to this relationship is also protected, so that the conservation of biological diversity of useful plant species favors the protection of cultural diversity associated to its plant use. The urgency to conserve and protect the Mexican germplasm is associated to the fast and dramatic change of habitats that the country is facing. In megadiverse countries with serious institutions, such as the Seed Bank FESI-UNAM, has undertaken efforts to conserve seeds from species of wild plants and particularly useful wild species, so that it is possible to have the raw material to carry out taxonomical, ethnobotanical, genetics, ecological and phytochemical studies and sustainable projects.

Se documentaron los usos y el manejo tradicional de la especie Pachycereus hollianus en el Valle de Zapotitlan, dentro de la Reserva de la Biosfera del Valle de Tehuacan-Cuicatlan, en el centro de Mexico. Mediante entrevistas abiertas y semi-estructuradas, se encontro que la gente de la region sigue utilizando sus productos (tallos, madera y frutos). Se identificaron 6 variantes locales con diferentes tipos de frutos comestibles y se observo una clara asociacion de las poblaciones de plantas con las poblaciones humanas. Los mejores fenotipos, con frutos mas grandes y pulpa roja de sabor dulce, son protegidos en areas manejadas, de manera que el manejo puede haber tenido efectos sobre la frecuencia de genotipos dentro de las poblaciones de P. hollianus, incrementando la abundancia de algunos de ellos a traves de la seleccion artificial, ejercida principalmente sobre estructuras de reproduccion sexual.

An ethnobotanical survey was conducted to document uses and traditional management of Pachycereus hollianus in the Valley of Zapotitlan, within the Tehuacan-Cuicatlan Valley in Central-Mexico. Open and semistructured interviews showed that local people still use its products (stems, wood and fruits). Six local variants with different kinds of edible fruit were identified and a clear association between plant and human populations was observed. The best phenotypes with large fruit and a red sweet pulp were found to be protected in managed areas and such management might have had effects on phenotype frequency in P. hollianus populations, increasing abundance through artificial selection principally directed towards sexual reproduction structures.

Sicyos mcvaughii , a new species from Oaxaca, is described and illustrated. It is similar to Sicyos sertuliferus Cogn., and grows in secondary tropical deciduous forest, between 20 and 630 meters.

Two new species of Sicyos from Mexico are described and illustrated: Sicyos cordifolius from the state of Guerrero, which belongs to the group with dry, armed fruits, and Sicyos bulbosus from the state of Oaxaca, which belongs to the group with fleshy, unarmed fruits. Sicyos cordifolius is quite different from the rest of the species previously described. Although S. bulbosus is very similar to S. galeottii Cogn., it is clearly different in receptacle shape and size. (C) 2004 The Linnean Society of London.

Sicyos lirae is described as a new species from Chiapas, Mexico, and Guatemala. It grows in zones with primary or secondary montane rain forest at elevations between 1400 and 3800 meters. In Guatemala the species is commonly called “güisquil de ratón.” It is similar toSicyos galeottii Cogn., from which it differs in blade consistency, shape of the stigma lobes, and several important ovary and fruit characters.

Information on richness of plant resources, and their forms of use and management in the biosphere reserve Tehuacan-Cuicatlan, Mexico is analyzed. This 10 000 km2 region hosts nearly 2700 vascular plant species, and it is acknowledged as one of the arid areas with the highest floristic diversity in North America. The seven indigenous ethnic groups that live in this region have cultural roots that date back almost 10 000 years. Based upon ethnobotanical and floristic studies, as well as bibliographical sources, a total of 808 useful plant species were identified, most of them (90%) being native, and 44 species being endemic to the region. A total of 681 species are wild plants, 109 are weeds and ruderal plants, and 86 are domesticated crops. However, it was noted that considerable overlap exists between the species of these 3 categories. For example, while wild and ruderal plants (706 species) are foraged by both humans and domestic animals, 59 species of this group are also managed in situ. On the other hand, 168 wild, ruderal and domesticated species are cultivated. The Tehuacán-Cuicatlan Valley is one of the richest regions of Mexico in plant resources. Local knowledge on use and management of plants is a valuable source of information for designing conservation and social development strategies for the biosphere reserve.