Predicción de la riqueza de especies del sotobosque a partir de las características de manejo y del rodal mediante árboles de regresión

Managing forests for multiple ecosystem services such as timber, carbon, and biodiversity requires information on ecosystem structure and management characteristics. National forest inventory data are increasingly being used to quantify ecosystem services, but they mostly provide timber management and overstory data, while data on understory shrub and herbaceous diversity are limited. We obtained species richness and stand management data from relevant literature to develop a regression tree model that can be used to predict understory species richness from forest inventory data. Our model explained 57% of the variation in herbaceous species richness in the coastal plain pine forests of the southeastern USA. Results were verified using field data, and important predictors of herbaceous richness included stand age, forest type, time since fire, and time since herbicide-fertilizer application. This approach can make use of available forest inventories to rapidly and cost-effectively estimate understory species richness for subtropical pine forest

Application of Nanostructured Carbon-Based Electrochemical (Bio)Sensors for Screening of Emerging Pharmaceutical Pollutants in Waters and Aquatic Species: A Review

Pharmaceuticals, as a contaminant of emergent concern, are being released uncontrollably into the environment potentially causing hazardous effects to aquatic ecosystems and consequently to human health. In the absence of well-established monitoring programs, one can only imagine the full extent of this problem and so there is an urgent need for the development of extremely sensitive, portable, and low-cost devices to perform analysis. Carbon-based nanomaterials are the most used nanostructures in (bio)sensors construction attributed to their facile and well-characterized production methods, commercial availability, reduced cost, high chemical stability, and low toxicity. However, most importantly, their relatively good conductivity enabling appropriate electron transfer rates—as well as their high surface area yielding attachment and extraordinary loading capacity for biomolecules—have been relevant and desirable features, justifying the key role that they have been playing, and will continue to play, in electrochemical (bio)sensor development. The present review outlines the contribution of carbon nanomaterials (carbon nanotubes, graphene, fullerene, carbon nanofibers, carbon black, carbon nanopowder, biochar nanoparticles, and graphite oxide), used alone or combined with other (nano)materials, to the field of environmental (bio)sensing, and more specifically, to pharmaceutical pollutants analysis in waters and aquatic species. The main trends of this field of research are also addressed.This work was financially supported by: projects UID/QUI/50006/2019 and PTDC/ASP-PES/29547/2017 (POCI-01-0145-FEDER-029547) funded by FEDER funds through the POCI and by National Funds through FCT - Foundation for Science and Technology. This proposal was also subsidized by the Brazilian agencies CNPq (Proc. 420261/2018-4) and CAPES (Proc. 88881.140821/2017-01; Finance code 001). F.W.P. Ribeiro acknowledges funding provided by FUNCAP-BPI (Proc. BP3-0139-00301.01.00/18). Acknowledgments T.M.B.F. Oliveira thanks the UFCA’s Pro-Rectory of Research and Innovation for initiating his investigations. F.W.P. Ribeiro thanks the CNPq (proc. 406135/2018-5) and all support provided by the UFCA‘s Pro-Rectory of Research and Innovation. A.N. Correia thanks the CNPq (proc. 305136/2018-6).info:eu-repo/semantics/publishedVersio

Stomatal responses of Eucalyptus species to elevated CO2 concentration and drought stress

Five species of Eucalyptus (E. grandis, E. urophylla, E. camaldulensis, E. torelliana, and E. phaeotrica), among the ten species most commonly used in large scale plantations, were selected for studies on the effects of elevated CO2 concentration [CO2] and drought stress on stomatal responses of 2.5-month old seedlings. The first three species belong to the subgenus Smphyomyrtus, whereas the fourth species belongs to the subgenus Corymbia and E. phaeotrica is from the subgenus Monocalyptus. Seedlings were grown in four pairs of open-top chambers, arranged to have 2 plants of each species in each chamber, with four replications in each of two CO2 concentrations: 350 ± 30 mumol mol-1 and 700 ± 30 mumol mol-1. After 100 days in the chambers, a series of gas exchange measurements were made. Half the plants in each chamber, one plant per species per chamber, were drought-stressed by withholding irrigation, while the remaining plants continued to be watered daily. Drought stress decreased stomatal conductance, photosynthesis and transpiration rates in all the species. The effect of drought stress on stomatal closure was similar in both [CO2]. The positive effects of elevated [CO2] on photosynthesis and water use efficiency were maintained longer during the stress period than under well-watered conditions. The photosynthetic rate of E. phaeotrica was higher even in the fourth day of the drought stress. Drought stress increased photoinhibition of photosynthesis, as measured by chlorophyll fluorescence, which varied among the species, as well as in relation to [CO2]. The results are in agreement with observed differences in stomatal responses between some eucalyptus species of the subgenera Symphyomyrtus and Monocalyptus

SELECTION OF EUCALYPTUS CLONES AND ADJUSTMENT OF POTASSIUM DOSES FOR EXTENDED DROUGHT IN BAHIA SAVANNA

ABSTRACT The use of clones adapted to regions with water deficit caused by well-defined and prolonged dry periods, as happens in the western part Bahia, is a way to overcome water stress. The adjustment of potassium (K) also influences this aspect, because it regulates the opening and closing of stomata, impeding water loss by plants and making them more efficient in water use. Therefore, the aim of this study was to evaluate the performance of eucalyptus clones grown for energy production in response to potassium levels in soil and climate conditions, in the municipality of Luis Eduardo Magalhães, located in western Bahia state. A randomized block with four replications in a split plot was used as experimental design. Six eucalyptus clones (AEC-056, CEA-144, CEA-220, CEA-224, CEA-103 and CEA-1528) and four doses of K2O (0, 30, 60 and 120 kg ha-1) were tested. At two years old, clone 1528 showed greatest productivity, with the tallest height and trunk diameter, while 056 showed the lowest performance. Different K requirements were observed among eucalyptus clones for both growth and productivity

Soil water dynamics and litter production in eucalypt and native vegetation in southeastern Brazil

High productivity of eucalypt plantations is the result of advances in research that have led to gradual improvements in intensive silvicultural technology. High productivity notwithstanding, eucalypt plantations remain the focus of environmental concerns. Our study aimed to compare the soil water regime, litter fall and nutrients dynamics either in a fragment of native forest or in an adjacent stand of growing eucalypt. We took field measurements during the first three years of eucalypt plantation in a sandy soil in the southeastern region of Brazil. Soil moisture and internal drainage were higher during the early stages of growth of the eucalypt stand, as compared with native vegetation. However, one and a half years after planting, available soil water was similar in both vegetations. Higher water availability under the eucalypt stand during the first year occurs because of silvicultural operations (soil preparation and weed control) and the small size of eucalypt trees; these factors increase water infiltration and decrease transpiration. Total leaf fall, over the study period, was similar for both ecosystems; however, differences were observed in the winter and early spring of 2010. The transfer of nutrients to soil by leaf fall was similar except for N and S, which was higher in native vegetation. Nitrogen concentration in the soil solution was higher in native vegetation, but K was higher under the eucalypt stand, mainly to a depth of up to 0.2 m

Floristic variations in a woody plant community along a trail in a Semideciduous Seasonal Forest, Viçosa, Minas Gerais State, Brazil

The opening and use of a trail can modify abiotic factors along its route and in the closer surroundings. These changes can be verified by floristic changes of vegetation. This study evaluated a possible influence of a trail on the woody vegetation (DBH ³ 2.5 cm, except lianas) in a Semideciduous Seasonal Forest in Viçosa, Minas Gerais State, Brazil (20º45'S and 42º51'W). Ten plots were sampled in an area near a trail and 10 other plots in the forest interior, totaling 718 individuals. Cluster (WPGMA) and ordination (DCA) analysis suggest that it may be a certain degree of influence of the trail on vegetation, although some results were intriguing. Further studies may be added to this in order to establish, in the future, environmental policies that take this source of interference with native ecosystems into account