Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Background and study species: The endangered oak Quercus brandegeei Goldman, endemic to Baja California Sur, Mexico, is threatened because of its relictual distribution restricted to ephemeral riverbeds, declining populations, and a lack of seedling regeneration. Although there is evidence of viable acorn production, no seedlings or saplings have been found across the range of occurrence for this species. Hypothesis: We tested for spatial aggregation and factors determining acorn production, hypothesizing that Q. brandegeei trees would be less distant from one another in regions with higher precipitation and that tree attributes and climatic variables would co-determine acorn presence. Study site and dates: Baja California Sur, Mexico, 2016-2017 Methods: We conducted a Ripley’s K analysis to determine each population’s spatial pattern (random, uniform, clumped) across 12 populations and a total of 194 individuals. To find the impact of environmental factors on acorn production we conducted a series of generalized linear models on eight climatic variables. Results: Ripley’s K analysis revealed that Q. brandegeei is a highly clumped species, with the highest rate of aggregation occurring within 0-25 meters. Region but not climatic cues were found to be important determinants of presence of acorns. Conclusions: High aggregation in clumps and low evidence of acorn production in some populations suggests that there is a niche attrition for this species, which is confined to very specific microsites along ephemeral riverbeds. Suitable recruitment areas could be reduced even further under the hotter and drier climate predicted for the region.

Background: Capsicum annuum var. glabriusculum is the ancestor of most of the economically important chiles in the world. It is widely distributed throughout Mexico, and currently all indigenous groups interact with this plant species. On the Yucatan Peninsula wild chile is known as maax ik by the Maya. Although this area has been recognized as a domestication and diversification center of chile, ethnobotanical research on this species is still limited.      Questions: What ecological knowledge do local people have about maax ik? Where and how is maax ik gathered and managed? What uses does maax ik currently have? Studied species: Capsicum annuum var. glabriusculum Study site and dates: San Bernardo, Yucatan. Summer-Autumn 2021. Methods: In-depth semi-structured interviews and participatory observation. The management practices were identified, and management intensity was estimated. Results: Informants knew that maax ik reproduces sexually and recognized the role of birds in its seed dispersal. Maax ikwas mainly gathered from homegardens where this species was tolerated and other non-selective incipient management practices such as protection and promotion were also carried out. Fruit was harvested without harming the plant and only a small portion of the available fruit was usually taken. The informants used maax ik essentially as food. The management intensity index was relatively high (5). Conclusions: Maax ik is a sustenance food resource that is sustainably used and non-selectively managed in homegardens by our informants in San Bernardo, Yucatan.

Background: Centrosema (Fabaceae) includes 35-44 species in the New World, 10 in Mexico, and 9 in the Yucatan Peninsula. Most species have trifoliolate leaves and bicolored flowers. Unifoliolate leaves are an infrequent character that is found in a few species, e.g., C. sagittatum (Humb. & Bonpl. ex Willd.) Brandegee, but monochromatic flowers, e.g, lacking nectar guides, is even a more unusual character state. Several populations of a Centrosema from the Yucatan Peninsula share both character states, a combination that sets them apart from other members of the genus. Question: Is the Centrosema with unifoliolate leaves, alate petioles, and monochromatic flowers of the Yucatan Peninsula, a species distinct from the phenetically similar C. sagittatum? Studies species: Centrosema (Fabaceae, Papilionoideae). Study site and dates: Yucatan Peninsula, Mexico, 2021-2023. Methods: Botanical specimens were collected and determined taxonomically through the use of relevant literature, keys, and the consulting of botanical collections. The conservation status of the new species was assessed using the IUCN methodology. Results: The specimens collected do represent an undescribed species that differs from Centrosema sagittatum by its smaller, cream-yellow, monochromatic flowers. The species is assessed as Endangered (EN). Conclusions: A new species, Centrosema flavescens from the Yucatan Peninsula is proposed. Eleven species of Centrosema are now recognized in Mexico, nine in the Yucatan Peninsula. C. sagittatum does not occur in the Yucatan peninsula.

Background: Percentage and speed of germination are crucial factors that can restrict processes involved in plant succession during ecological restoration. Pre-germination treatments and the effect of storage time on germination percentage and mean germination time were investigated in nine native herbaceous plants of the La Primavera Flora and Fauna Protection Area. Question: Do the seeds of the studied species go dormant, and can storage time affect germination percentage and mean germination time? Species studied: Aeschynomene villosa var. longifolia (Micheli) Rudd, Crotalaria pumila Ort., Dalea leporina (Ait.) Bullock, D. foliolosa (Ait.) Barneby, Desmodium aparines (Link) DC., D. distortum (Aubl.) JF Macbr., D. tortuosum (Sw.) DC., Paspalum notatum Flüggé, and Zornia reticulata I. E. Smith. Place and dates of study: Area of Protection of Flora and Fauna La Primavera. From 2019 to 2020 Methods: Under greenhouse conditions, four treatments were applied prior to germination: scarification with a tweezer pliers, immersion in water at 40 ᵒC for 24 and 48 h, and control. Results: Seven species had highly viable (≥ 90 %) seeds after 12 months of storage. Five species with seed dormancy reached germination above 80 % after 24 months of storage and scarification with a tweezer pliers. Mean germination time for most species decreased with the scarification treatment. Conclusion: Our findings provide basic information on the germination of native species that could help restore degraded sites in the La Primavera Flora and Fauna Protection Area.

Background: Lichen diversity in the Mexican state of Aguascalientes has historically been neglected. Lichen species in all vegetation types, except for the arid zones, remain underexplored. Hypotheses: Lichenized fungi richness reported for Aguascalientes will increase due to exploration and collecting activities in vegetation types other than xerophilous scrubs. This will allow finding species of interest for conservation purposes, including Mexican endemics and/or threatened taxa. Data description: Lichenized fungi, vegetation types, substrates. Study site and dates: Mexican state of Aguascalientes, 2018 to 2021. Methods: Revision and taxonomic identification of lichenized fungi specimens deposited at the HUAA herbarium. Once the endemic species were detected, the Extent of Occurrence (EOO) and the Area of Occupancy (AOO) were calculated to assess their conservation status according to the IUCN Red List. Results: 162 new records were found for Aguascalientes. Chrysothrix insulizans R.C. Harris & Ladd, Hertelidea botryosa (Fr.) Kantvilas & Printzen, and Sarcogyne novomexicana H. Mag., were new records for the country. The epiphytic substrate and the foliose growth form were dominant. Parmotrema acutatum had an EOO = 192,141 km2, while Phaeophyscia sonorae had a EOO = 18,285 km2. Conclusions: The number of lichenized fungi species recorded for Aguascalientes increased to 218. We suggest publication of Parmotrema acutatum Kurok. as Least Concern (LC) and Phaeophyscia sonorae Essl. as Vulnerable (VU) in the IUCN Red List.

Background: Bromeliaceae are widespread in Mexico and present in all types of vegetation. A high number of species are restricted to the country. Jalisco is the fifth Mexican state regarding Bromeliaceae richness and 18 % of its species are state endemics. Questions and / or Hypotheses: How bromeliads are distributed in Western Sierra-Coast region of Jalisco? What is the endemism status of bromeliads in the region? Studied species: Native Bromeliaceae of WSC. Study site and dates: WSC region in Jalisco, collections from 1926 to 2020. Methods: Data were obtained by herbarium material revision and field expeditions. We analyzed life form, distribution by vegetation type, altitudinal range, and recollection activity per year. A richness map was generated. To determine the affinity of the bromeliad flora with other regions of the state, a cluster analysis was performed using UPGMA method. Results: We found nine genera and 53 species, richest genera were Tillandsia and Pitcairnia. Epiphyte was the commonest life form. Oak forest had the highest species number, most taxa were found between 250-750 m asl. Most collections come from the municipality of Cabo Corrientes accounting for 66 % of total species in WSC. The study area hosts, six species of endemic bromeliads. Conclusions: Despite to their restricted distribution, none of the endemic species from WSC are listed under special protection. The WSC should be considered for conservation. The tourism development, deforestation and climate change could have a negative impact on bromeliads, especially epiphytes that depend entirely on the host trees.

Background: Plant-plant facilitation provides benefits to the protected species since the host species reduces the intensity of stressful physical conditions. However, it has been hypothesized that the outcome of the interaction could be regulated by the characteristics of the interacting species and that herbivores could counteract the benefits of protective plants. Question: Can cactus size and identity of neighboring plants influence the herbivory of the columnar cactus P. leucocephalus? Studied species / Mathematical model: Pilosocereus leucocephalus (Poselg.) Byles & G.D. Rowley /One-way ANOVA, Repeated measures ANOVA, Analysis of covariance and linear regression. Study site and dates: San Ignacio, Veracruz, Mexico. April to May 2019. Methods: We randomly selected 60 P. leucocephalus plants growing underneath the canopy of seven species of shrubs and P. leucocephalus plants growing ≥ 3 m away from other species and exposed to full sunlight conditions. We obtained the size of the P. leucocephalus plants (size of main stem from ground to apex) and determined the intensity (number of bites on the stem) of vertebrate herbivory. Results: The number of bite scars by small vertebrate species was significantly higher on the stems of cacti established in open spaces than on those underneath the canopy of seven shrub species and increased significantly with the stem size of the protected species. Conclusions: We conclude that herbivory damage by rodents on a giant cactus in a dry tropical forest depends on cactus size and the identity, but not the shade, of the nearest neighbor.

Background: Water deficit and salinity are common conditions in arid agro-ecosystems. Hypothesis: Salinty increases the hydric stress effect on the yield and gel quality of Aloe vera. Study species and data description: In A. vera plants the variables meassured were: plant height, leaf length, width, and thickness, fresh biomass, the relative content of water, total solids, gel percentage, and harvest index. Study site and dates: The study was conducted from spring to summer 2020 in Bermejillo, Durango, Mexico. Methods: A split-block experimental design with four replications was used. The large plots were two soil moisture contents: field capacity (18.5 ± 2.5 %) and permanent wilting point (12.5 ± 2.5 %). The small plot was the salinity, with levels: 0, 20, 40, 60, and 80 mM of NaCl.   Results:Water deficit and salinity reduced the width and thickness of leaves and, consequently, the fresh biomass and gel percentage were reduced, but gel quality increased. Conclusions: Water deficit and salinity, mainly the latter, reduced plant growth and leaves, and therefore, the yield of fresh biomass and gel. Although gel yield was reduced, its quality was enhanced, in terms of high total solids content.

Background: Palynological studies have contributed with topics closely linked to sustainability. However, there are still few scientific reviews that have discussed the relevance of practical applications in current palynology and its perspectives as a theoretical framework for the study of integrated landscape management. This review shows palynological contributions within agricultural model diversities in both natural and novel ecosystems. Questions: What are the current perspectives and concerns of the mature phase in palynology? What are the approaches of pollen analysis on landscape management and biodiversity conservation?Studied species: Pollen analysis and palynomorphs.Study site and dates: Global literature from current palynology.Methods: Global scientific literature using keywords, theoretical frameworks, and original articles.Results: We identified palynological perspectives for the study of sustainability based on global scientific literature: 1) ecological-evolutionary and 2) interdisciplinary research. In addition, we discussed some synergies and trade-offs between ecosystem services that were recognized through current palynology in different farming landscapes: biodiversity-based farming systems and chemical input-based farming systems. While pollen morphology and descriptive palynology can provide the basis for crop improvement, biological invasions, and the effect of deforestation on native species, more analytical approaches such as land-use indicators are necessary for sustainable management. In addition, we have included some biocultural aspects to conservation, due to a lack of practical discourse in current palynology. Conclusions: Innovative influences from current palynology are powerful approaches to integrated landscape management.

Background: Oaxaca, a southern State in Mexico, belongs to the Mesoamerican hotspot of biodiversity. The taxonomic and diversity knowledge of arbuscular mycorrhizal fungi (AMF) in Oaxaca State is scattered and accessibility to it is difficult. Questions: Which AMF species have been identified in Oaxaca and which is their distribution? Studied species: Arbuscular mycorrhizal fungi. Study site: State of Oaxaca, Mexico. Methods: It was prepared an updated and annotated checklist of the AMF species with frequency of occurrence and the sampling sites where the species had been registered. All studies carried out previously (to date, 2022) were considered. Information on AMF taxa was available in scattered form in different publications in physical and electronic media, theses, projects, technical reports, and scientific papers. Results: The checklist includes 78 species, distributed among 23 genera, 10 families, and four orders. The most diverse families were Glomeraceae (26 species), followed by Gigasporaceae (20) and Acaulosporaceae (15), whereas the most diverse genera were Acaulospora and Glomus (15 and eight species, respectively). The most frequent species were Funneliformis geosporus, Acaulospora scrobiculata, and A. spinosa. The highest species diversity has been reported under the rhizosphere of Agave angustifolia, A. karwinskii, and Zea mays (39, 36, and 34 species, respectively). A new AMF species was recently isolated from the rhizosphere of a microendemic agave. Conclusions: The recorded AMF species of Oaxaca State confirms its position as one of the states with the highest AMF species diversity of Mexico.