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Background: Agri-silvicultures (ASC) are biocultural practices procuring either the maintenance of wild diversity in predominantly agricultural spaces or introducing agrobiodiversity into forests. In the Mesoamerican region, ASC contribute to food sovereignty and territorial conservation and provide strategies for dealing with global changes. Previous inventories of ASC identified gaps in information about these systems in the Mexican Arid America region. This article raises the general question: How have human interactions between cultural, wild, and domesticated biodiversity in this territory? The particular questions in this paper are: (i) How have historical processes shaped human interactions between wild and domesticated biodiversity in the region? and (ii) What types of agri-silvicultures have emerged in Mexican Arid America since these relationships? Methods: We trace a methodological border where archaeologists have identified the Mesoamerican region to define our study area as Arid America northern of this line in Mexico. We analyzed agriculturalization processes in Arid America through a historical review. Then, we carry out an inventory of Arid America ASC based on academic papers and other documented experiences. We constructed a spatial database and a typology to understand what kinds of agri-silviculture occur in the region. Results: We identified several pre-Hispanic agri-silvicultural practices in the region, like hunting, fishing, terraces, gathering, and irrigation systems. The cultivation of native species of maize, beans, and squash even was registered. The Spanish colonization forced the agriculturization in arid northern Mexico, where itinerant hunting-gathering patterns predominated. In the twentieth century, the Green Revolution adopted this area as the principal setting for industrialized agriculture. The industrialized irrigated systems expansion and other political strategies provoked the simplification of productive landscapes. The practices that integrate wild and agricultural diversity systems were marginalized and invisibilized in such a context. Our research group proposes seven types of agri-silvicultural systems (natives agrisilvicultures, the oases agroforestry, Mesquite and Huisache ASC, homegardens and other traditional forms of agroforestry or agri-silvicultures). These agri-silvicultures provide food, medicine, fodder, and other contributions, as income to the families that practice them and protect native and exotic species. Discussion and conclusion: The agriculturization of the arid environments initiated during Spanish colonization and the subsequent modernizing projects shaped dominant actors and ideologies in the arid north of Mexico. However, aridity has favored ancestral and agroecological relationships between cultures and biodiversity, emerging and subsisting Arid American agri-silvicultures. These agri-silvicultures deserve to be understood, adopted, and adapted to new contexts. They could be essential alternatives in the context of environmental changes. [ABSTRACT FROM AUTHOR]

Mining is one of the major pollution sources worldwide, causing huge disturbances to the environment. Industrial and artisanal mining activities are widespread in Mexico, a major global producer of various metals. This study aimed to assess the ecological impairments resulting from mining activities using aquatic macroinvertebrates assemblages (MA). A multiple co-inertia analysis was applied to determine the relationships between environmental factors, habitat quality, heavy metals, and aquatic macroinvertebrates in 15 study sites in two different seasons (dry and wet) along two rivers running across the Central Plateau of Mexico. The results revealed three contrasting environmental conditions associated with different MAs. High concentrations of heavy metals, nutrients, and salinity limit the presence of several families of seemingly sensitive macroinvertebrates. These factors were found to influence structural changes in MAs, showing that not only mining activities, but also agriculture and presence of villages in the basin, exert adverse effects on macroinvertebrate assemblages. Diversity indices showed that the lowest diversity matched both the most polluted and the most saline rivers. The rivers studied displayed high alkalinity and hardness levels, which can reduce the availability of metals and cause adverse effects on periphyton by inhibiting photosynthesis and damaging MAs. Aquatic biomonitoring in rivers, impacted by mining and other human activities, is critical for detecting the effect of metals and other pollutants to improve management and conservation strategies. This study supports the design of cost-effective and accurate water quality biomonitoring protocols in developing countries. [ABSTRACT FROM AUTHOR]

Rivers are critical ecosystems for protecting and harboring high biodiversity. Tropical rivers particularly are unique for facing extreme climatic events under the current accelerated disruption from human activities. The Bobos-Nautla river basin is exposed to climatic events and disturbances from anthropogenic impacts that stress aquatic organisms. We assessed the health condition of this river system using a non-conventional biomonitor, Corydalus sp., with a set of early-warning biomarkers including lipid peroxidation levels (LPO) and antioxidant activity, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and the neurotransmitter acetylcholinesterase (AChE) considering their spatial and temporal variations. Biomarkers and water quality parameters were analyzed, and the integrated biomarker response (IBR) was assessed as a stress index. Biomarkers showed no significant spatial differences; however, a high-stress period during the rainy season was detected, evidenced by the highest LPO levels; this period is related to the leaching of allochthonous materials from agricultural and urban zones. The peak IBR value during the rainy season confirmed the seasonality of biomarkers. A slight increase in IBR was recorded in lowlands, seemingly associated with agricultural land and human settlements. A principal component analysis showed nutrient enrichment during the rainy season and depletion during the cold-dry season, together with a peak activity of antioxidant enzymes. These results highlight the importance of climatic events such as the rainy season on the health condition of Corydalus sp., which is highly sensitive to the complex mixtures of pollutants that enter the waterbody during extreme climatic events, promoting oxidative stress. Our results also showed the ability of Corydalus sp. to recover and return to a basal level. [ABSTRACT FROM AUTHOR]

Background: Documenting the spectrum of ecosystem management, the roles of forestry and agricultural biodiversity, TEK, and human culture for food sovereignty, are all priority challenges for contemporary science and society. Ethnoagroforestry is a research approach that provides a theoretical framework integrating socio-ecological disciplines and TEK. We analyze in this study general types of Agroforestry Systems of México, in which peasants, small agriculturalist, and indigenous people are the main drivers of AFS and planning of landscape diversity use. We analyzed the actual and potential contribution of ethnoagroforestry for maintaining diversity of wild and domesticated plants and animals, ecosystems, and landscapes, hypothesizing that ethnoagroforestry management forms may be the basis for food sufficiency and sovereignty in Mexican communities, regions and the whole nation. Methods: We conducted research and systematization of information on Mexican AFS, traditional agriculture, and topics related to food sovereignty from August 2011 to May 2015. We constructed the database Ethnoagroforestry based on information from our own studies, other databases, Mexican and international specialized journals in agroforestry and ethnoecology, catalogues and libraries of universities and research centers, online information, and unpublished theses. We analyzed through descriptive statistical approaches information on agroforestry systems of México including 148 reports on use of plants and 44 reports on use of animals. Results: Maize, beans, squashes and chili peppers are staple Mesoamerican food and principal crops in ethnoagroforestry systems practiced by 21 cultural groups throughout Mexico (19 indigenous people) We recorded on average 121 ± 108 (SD) wild and domesticated plant species, 55 ± 27% (SD) of them being native species; 44 ± 23% of the plant species recorded provide food, some of them having also medicinal, firewood and fodder uses. A total of 684 animal species has been recorded (17 domestic and 667 wild species), mainly used as food (34%). Conclusions: Ethnoagroforestry an emergent research approach aspiring to establish bases for integrate forestry and agricultural diversity, soil, water, and cultural richness. Its main premise is that ethnoagroforestry may provide the bases for food sovereignty and sustainable ecosystem management. [ABSTRACT FROM AUTHOR]

Background: Traditional climate knowledge is a comprehensive system of insights, experiences and practices used by peasant communities to deal with the uncertainties of climate conditions affecting their livelihood. This knowledge is today as relevant in the Mesoamerican and Andean regions as it is in Europe and Asia. Our research sought to analyze the traditional knowledge about the weather and climate in a rural village of the state of Tlaxcala, Mexico, and its importance in decision-making in agriculture. Methods: Through 30 interviews and participant observation in the community during 2013, information was gathered about traditional climate and weather indicators and prediction tools, as well as rituals and agronomic and agroforestry strategies. This information allowed for the reconstruction of the community's agro-festive calendar. Data analysis was carried out with the help of the qualitative analysis software Atlas.ti (version 7). Results: The socio-ecological importance of traditional knowledge about the climate lies in its ability to forecast local weather conditions and recognize climate variations, so vital to the food security of rural families. Knowledge about climate predictors is exchanged and passed on from generation to generation, contributing to the preservation and promotion of biodiversity. By observing the behavior of 16 animals and 12 plant species (both domestic and wild) as well as seven astronomical indicators, villagers are able to predict rain, dry weather and frosts. However, the continuity of this traditional knowledge in the community under study is now compromised by the little interest in agriculture characteristic of the younger generations, the ensuing abandonment of the countryside, the widespread economic crisis and the disappearance of animal and plant species. Conclusions: Traditional climate knowledge includes the understanding of weather events and weather changes at different time scales (hours, days, weeks, and seasons). The ability to interpret weather events thanks to the accumulated knowledge about the climate through generations may prove today a relevant tool for improving agricultural practices and dealing with local and global socio-ecological changes. [ABSTRACT FROM AUTHOR]

The analysis of functional diversity has shown to be more sensitive to the effects of natural and anthropogenic disturbances on the assemblages of aquatic macroinvertebrates than the classical analyses of structural ecology. However, this ecological analysis perspective has not been fully explored in tropical environments of America. Protected Natural Areas (PNAs) such as biosphere reserves can be a benchmark regarding structural and functional distribution patterns worldwide, so the characterization of the functional space of biological assemblages in these sites is necessary to promote biodiversity conservation efforts. Our work characterized the multidimensional functional space of the macroinvertebrate assemblages from an ecosystemic approach by main currents, involving a total of 15 study sites encompassing different impact and human influence scenarios, which were monitored in two contrasting seasons. We calculated functional diversity indices (dispersion, richness, divergence, evenness, specialization, and originality) from biological and ecological traits of the macroinvertebrate assemblages and related these indices to the physicochemical characteristics of water and four environmental indices (Water Quality Index, habitat quality, Normalized Difference Vegetation Index, and vegetation cover and land use). Our results show that the indices of functional richness, evenness, and functional specialization were sensitive to disturbance caused by salinization, concentration of nutrients and organic matter, and even to the occurrence of a forest fire in the reserve during one of the sampling seasons. These findings support the conclusion that the changes and relationships between the functional diversity indices and the physicochemical parameters and environmental indices considered were suitable for evaluating the ecological conditions within the reserve. [ABSTRACT FROM AUTHOR]

The Lake of Texcoco is a closed basin with soils that confer salinity, conductivity, and alkalinity to it. It has undergone a reduction in size, incorporation of wastewater, and short-term desiccation, and includes temporary wetlands interconnected during the rainy season, some of which receive treated wastewater. Sediments contain metals, thus affecting water quality. Five artificial lakes were studied, and 12 metals (As, Ba, Cd, Cu, Cr, Fe, Mg, Mn, Hg, Ni, Pb, and Zn) were monitored bimonthly in water and sediments from June 2015 to March 2018. The Metal Pollution Index (MPI) and the Distribution Coefficient (Kd) were computed. Fe and Cd were the most and least stable metals in sediments, respectively (mean Log(Kd) = 4.24 and 2.079). Based on Log(Kd), metals were ranked as Fe > Mn > Zn > Cu > Mg > Cr > Ni > Ba > Pb > Hg > As > Cd. Log(Kd) values < 3 and > 5 indicate that metals occur mainly in water and sediments, respectively. The Mean Distribution Coefficient Log(Kd MPI) is a novel index proposed to assess ecological risk from metals in a water body. This index allows determining the phase (liquid or solid) where metals predominate, negatively affecting either free-swimming or benthic organisms. Log(Kd MPI) values indicated that metals occur primarily in the liquid phase in all lakes studied. [ABSTRACT FROM AUTHOR]