First record of the tropical house gecko Hemidactylus mabouia (Moreau de Jonnès, 1818) in Texas

Invasions of the tropical house gecko Hemidactylus mabouia (Moreau de Jonnes, 1818) in the tropical Americas are well documented. While this gecko has been reported as well established and expanding its range in Florida, here we document the first record in the United States outside of this state. We detected a small reproducing population in Cameron County, Brownsville, Texas. We expect a rapid colonization of buildings by this species in southern Texas. We consider that this potential invasion poses novel obstacles to the continued presence of the earlier invasive Mediterranean gecko Hemidactylus turcicus (Linnaeus, 1758) across Texa

Enhancing the seed germination process of Montezuma cypress (Taxodium mucronatum Ten.)

Montezuma cypress (Taxodium. mucronatum) is an ecological, cultural and economically valuable riparian tree species. Two experiments evaluating the effectiveness of various seed treatments were conducted to identify germination best practices and to evaluate the dynamics of the germination process. Seeds were collected on two occasions, one year apart, from the only remaining natural T. mucronatum tree stand in the United States. The seeds were subjected to various soaking and stratification conditions. Across all treatments, germinability ranged between approximately 30%-40%, with slightly higher values occurring among the second seed cohort. Overall, no significant differences in germinability were detected in either study, however, soaking seeds in water for 96 hours and stratifying them in moist conditions for 3 weeks significantly accelerated the germination process. Seeds soaked briefly in a NaOH solution followed by a 48-hour water soak demonstrated more synchronous germination than other treatments. Control conditions in which seeds were not soaked or stratified exhibited the slowest germination. These findings are consistent with previous evidence showing that T. mucronatum seeds do not exhibit physiological dormancy and that treatments promoting seed water imbibition enhance the germination process. This study adds to the limited available research on T. mucronatum propagation practices and offers novel data on the germination parameters of seeds sourced from a natural U.S. stand, rather than seeds from few scattered individual trees, as in previous reports. Seed germination recommendations garnered from this study can improve nursery production of T. mucronatum to enhance ecological restoration efforts and ornamental production

Indicadores funcionales y estructurales para evaluar el estado de conservación de humedales costeros en el sur de Tamaulipas

El manejo adecuado de las zonas costeras requiere de herramientas que permitan detectar procesos degradantes en los ecosistemas estratégicos prestadores de servicios ambientales. Los indicadores ecológicos responden adecuadamente a esta necesidad en humedales costeros. Se estudiaron ocho humedales de origen y características distintas, con afectaciones contrastantes conocidas. Se seleccionaron los indicadores que mejor discriminaron los sitios y se utilizaron para evaluar la evolución del estado de conservación de los mismos. La correspondencia ecológica entre indicadores funcionales y estructurales no se confirmó en todos los casos, por lo que es necesario utilizar ambos tipos para obtener un mejor diagnóstico. En dicha contribución se muestra la utilidad del uso simultáneo de indicadores funcionales y estructurales para detectar, tanto degradación, como recuperación de este tipo de ecosistemas acuáticos. Los resultados presentados son parte del primer estudio conocido para desarrollar indicadores ecológicos en humedales costeros tropicales

Fish Assemblage Structure Indicates Limited Restoration Progress over a Lustrum of a Severely Degraded Estuary in Southern Tamaulipas, Mexico

Today the biggest incentive to attempt the restoration and protection of estuarine systems is their widely recognized ecological and economic importance. In the reconstruction of an estuary where the original aquatic communities disappeared before the restoration interventions, the fish assemblage is an adequate source of indicators of initial recovery. Following substantial restoration efforts, this study reports on the biannual for a lustrum monitoring and assessment of a severely degraded estuary (Garrapatas) in terms of its fish assemblage using a reference estuary (Barberena) in Tamaulipas, Mexico. Twenty fishes were associated with the restoring and reference estuaries. Species composition (richness, abundance, dominance) clearly showed differences among sites. No piscivorous estuarine or marine fishes were found in Garrapatas pointing at an unbalanced and incomplete trophic chain. On the other hand, the mangrove plant community appears to have fully recovered. Water parameters were more variable in Barberena compared to the restoring sites, especially salinity, DO, and pH, which were also higher. Estuaries are transitional systems with inherent variation of abiotic parameters. It is proposed that this variability of abiotic parameters still missing in the restored sites, and may be key to the full recovery of biotic assemblages and ecosystem function

Decomposition of paper de-inking sludge in a sandpit minesoil during its revegetation

Paper de-inking sludge was used as an organic amendment for revegetating an abandoned sandpit in Québec, Canada. In situ patterns of sludge decomposition and of total nitrogen and phosphorus dynamics were characterized in a litter bag study. In a one-time operation, sludge was applied at a rate of 0 or 105 Mg dry matter ha−1, along with N at 3, 6 or 9 kg Mg−1 sludge and P at 0.5 or 1.0 kg Mg−1 sludge. Sludge and fertilizers were incorporated into the top 0.21 m of the minesoil and tall wheatgrass (Agropyron elongatum (Host) Beauv.) was seeded. Mass loss was well described by a double exponential model when cumulative degree-days (sum of daily temperature above 0°C) were used as the independent variable. Fifty-one percent of the initial material decomposed with a half life of 0.4 yr, whereas the remaining material had a much slower rate of decay with a half life of 13 yr. The large size and slow decomposition rate of the recalcitrant pool of this material were attributed to the high lignin content and the presence of clay in the sludge. Both N and P in decomposing sludge presented a short accumulation phase followed by a long release phase which likely contributed to the successful revegetation of this disturbed sandpit site

Identifying nitrogen source and seasonal variation in a Black Mangrove (Avicennia germinans) communityof the south Texas coast

Black mangrove (Avicennia germinans) stands in south Texas grow in association with other autotrophic organisms including herbaceous halophytes and cyanobacterial mats. Despite the relevant ecosystem services provided by this coastal plant community, limited information exists on its functioning, in particular as it pertains to nutrient dynamics, namely nitrogen (N). Nitrogen stable isotopes were used to assess potential N sources for plant growth in this community. Plant tissue (leaves), cyanobacteria, and sediment were sampled once every season for one year. Total N in A. germinans (2.6 %) and associated saltwort (Batis maritima) (2.1 %) was higher than in cyanobacteria (0.6 %), and sediment (0.1 %). Isotopic signatures (δ15N) in A. germinans (5.85 ‰) and B. maritima (4.75 ‰) were more similar to sediment (5.21 ‰) than to cyanobacteria (1.98 ‰), suggesting mangroves and saltwort obtain N mostly from the sediment; no evidence of N transfer from cyanobacteria was found

Study of metals in leached soils of a municipal dumpsite in Tampico, Tamaulipas, Mexico: preliminary results

The Zapote dumpsite measures 420000 m 2 and is 28 years old; an estimated 2.5 millions tons of waste have accumulated on the site (household waste, clinical waste, commercial waste). The thickness of the waste is 3 to 9 meters. Since operations began, no control regulations have existed on the residues received. The Zapote dumpsite is located within a salt-marsh between a system of channels and river lagoons of brackish water, located in a tropical sedimentary environment in the urban zone of Tampico, Tamaulipas, Mexico. Recently, the Zapote has been closed and work is presently underway in its rehabilitation since a geo-environmental perspective. The present investigation integrates information of preliminary results of metals (Pb, Ni, Cd, Cu, Mg, Fe and Al) contained in sediments that underlie the Zapote dumpsite. In laboratory research the metals of the sediment were correlated with the metals contained in samples of leachate from the Zapote dumpsite. The concentration of metals Pb, Ni, Cd, Cu, Mg, Fe and Al were analyzed in samples of sediments that underlie the body of the dumpsite in layers of 10 cm, reaching a depth of 1.5 m under the interface waste-soil. The results denote high concentrations of metals in layers that are in contact with waste that decreased until reaching 60 to 80 cm of depth. The proportions of the concentrations of metals studied in the soil are comparable with that leached, until layers of 60 to 80 cm of depth are reached, and are then lost in the deepest layers. The high plastic characteristics of clay layers have stood in the way of metallic contaminants in sub layers of the Zapote dumpsite. The results were correlated with metal concentrations of natural and anthropogenic sediments of the region

Integrating Remote Sensing with Ground-based Observations to Quantify the Effects of an Extreme Freeze Event on Black Mangroves (Avicennia germinans) at the Landscape Scale

Climate change is altering the frequency and intensity of extreme weather events. Quantifying ecosystem responses to extreme events at the landscape scale is critical for understanding and responding to climate-driven change but is constrained by limited data availability. Here, we integrated remote sensing with ground-based observations to quantify landscape-scale vegetation damage from an extreme climatic event. We used ground- and satellite-based black mangrove (Avicennia germinans) leaf damage data from the northern Gulf of Mexico (USA and Mexico) to examine the effects of an extreme freeze in a region where black mangroves are expanding their range. The February 2021 event produced coastal temperatures as low as − 10 °C in some areas, exceeding thresholds for A. germinans damage and mortality. We used Sentinel-2 surface reflectance data to assess vegetation greenness before and after the freeze, along with ground-based observations of A. germinans leaf damage. Our results show a negative, nonlinear threshold relationship between A. germinans leaf damage and minimum temperature, with a temperature threshold for leaf damage near − 6 °C. Satellite-based analyses indicate that, at the landscape scale, damage was particularly severe along the central Texas coast, where the freeze event affected \u3e 2000 ha of A. germinans-dominated coastal wetlands. Our analyses highlight the value of pairing remotely sensed data with regional, ground-based observations for quantifying and extrapolating the effects of extreme freeze events on mangroves and other tropical, cold-sensitive plants. The results also demonstrate how extreme freeze events govern the expansion and contraction of mangroves near northern range limits in North America

Stability of fishes assemblage structure over a lustrum in coastal wetlands under different disturbances in an industrial zone of the central Gulf of Mexico coast

Shallow coastal wetlands within the territory of an industrial port in southern Tamaulipas, Mexico, were monitored seasonally over a lustrum, focusing on their fishes assemblage and water parameters. The purpose was to characterize these ecosystems that are affected by different disturbances of industrial origin, document changes, and assess potentially degrading terms as the affectations prevailed over the period of study. The wetlands are differentially affected by impacting land uses in their immediate surroundings, by crude oil leaks, and/or by diverse industrial wastewater discharges. Water parameters varied only slightly over time for most sites, and relative disparities among sites remained. The fishes assemblage was dominated by a native planktivorous species in eutrophic sites and by a native omnivorous fish in the oligotrophic wetland. The sole exotic species found was only the second-most dominant in all sites. The structure of the fish assemblage was maintained over time. Such stability is attributed to moderate temporal variation of water parameters; limited fish migration due to relative confinement of water bodies; and a reduced pool of species with dominant fishes potentially exhibiting trophic plasticity. These degraded aquatic ecosystems support a simplified but relatively stable fishes assemblage and may have reached an alternate steady state that could facilitate environmental management by the port authority