Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Crescimento inicial de Campomanesia xanthocarpa O. Berg sob diferentes composições de substratos

RESUMO:O objetivo do trabalho foi avaliar a influência de diferentes composições de substratos no crescimento inicial de Campomanesia xanthocarpa, bem como avaliar índices fisiológicos. O trabalho foi desenvolvido em Dourados-MS, no período de janeiro a outubro de 2008. Foi estudada aCampomanesia xanthocarpa sob cinco diferentes substratos (LVd/A/O= Latossolo Vermelho distroférrico+areia grossa lavada+Organosuper® (5:4:1 v/v); LVd/A/C= Latossolo Vermelho distroférrico+areia grossa lavada+cama-de-frango (5:4:1 v/v); LVd/A/O2= Latossolo Vermelho distroférrico+areia grossa lavada+Organosuper® (7:2:1 v/v); LVd/A/C2= Latossolo Vermelho distroférrico+areia grossa lavada+cama-de-frango (7:2:1 v/v); LVd/A= Latossolo Vermelho distroférrico+areia grossa lavada (6:4 v/v)), em vasos de 7 dm3, e mantidos em ambiente protegido com 100% de luminosidade. O substrato composto por Latossolo Vermelho distroférrico + areia grossa lavada proporcionou maior diâmetro de caule (8,29 mm), massa seca de raiz, caule e folhas (6,98; 4,49 e 9,06 g/planta, respectivamente) e aumento nos índices fisiológicos nas avaliações finais, indicando que este substrato pode ser utilizado no desenvolvimento de Campomanesia xanthocarpa

Espaçamentos entre plantas e adição de cama-de-frango na produção de biomassa das plantas e na composição química dos frutos da Campomanesia adamantium (Cambess.) O. Berg Spacing between plants and addition of chicken manure in the biomass production of plants and in the chemical composition of fruits of Campomanesia adamantium (Cambess.) O. Berg

O objetivo deste trabalho foi avaliar o efeito de espaçamentos entre plantas e o uso ou não de cama-de-frango semidecomposta incorporada ao solo na produção de biomassa das plantas e nos teores de fenóis, flavonóides e atividade antioxidante do extrato dos frutos da Campomanesia adamantium. O experimento foi desenvolvido no Horto de Plantas Medicinais - HPM, da Universidade Federal da Grande Dourados/UFGD, em Dourados-MS. Foi estudada a C. adamantium com cinco espaçamentos entre plantas, na linha (0,30; 0,35; 0,40; 0,45 e 0,50 m) e sem, ou com, cama-de-frango semidecomposta incorporada ao solo na dose de 10 t ha-1. Os tratamentos foram arranjados como fatorial 5 x 2, no delineamento experimental de blocos casualizados, com quatro repetições. Aos 390 dias após o transplante as plantas possuíam 54,89 cm de altura, 10,01 mm de diâmetro de caule e 178,27 folhas por planta. Os diâmetros, longitudinal (17,34 mm) e transversal (18,07 mm), dos frutos não variaram com os espaçamentos e nem com o uso da cama-de-frango. O maior número de frutos (28,56 frutos planta-1) e a maior massa fresca dos frutos (83,65 g planta-1) foram das plantas cultivadas sob os espaçamentos de 0,32 m e 0,35 m entre plantas, respectivamente, independente do uso ou não da cama-de-frango. A cama-de-frango induziu aumento significativo no teor de fenóis e reduziu o teor de flavonóides e a atividade antioxidante da polpa dos frutos. A cama-de-frango não influenciou a produtividade da C. adamantium nem a composição química dos frutos. Recomenda-se o uso do espaçamento 0,35 m entre plantas e 1,50 m entre fileiras, com o objetivo de produção de frutos.The aim of this study was to evaluate the effect of five spacing between plants and the use or not of semi-decomposed chicken manure incorporated into the soil on the biomass production of plants and on the levels of phenols, flavonoids and antioxidant activity of the extract of C. adamantium fruits. The experiment was carried out in the Medicinal Plant Garden - HPM, of Federal University of Grande Dourados/UFGD, in Dourados-Mato Grosso do Sul State, Brazil. C. adamantium was studied under five spacing between plants in a row (0.30; 0.35; 0.40; 0.45 and 0.50 m) and with and without semi-decomposed chicken manure incorporated in the soil, at a dose of 10 t ha-1. Treatments were arranged as 5 x 2 factorial, in randomized block design, with four replicates. At 390 days after transplanting, the plants had 54.89 cm height, 10.01 mm stem diameter and 178.27 leaves per plant. The longitudinal (17.34 mm) and transverse (18.07 mm) diameters of the fruits did not vary with the spacing or with the use of chicken manure. The largest number (28.56 fruits plant-1) and greatest fresh weight (83.65 g plant-1) of fruits were obtained for plants cultivated under spacing of 0.32 and 0.35 m between plants, respectively, independent of the use of chicken manure. The chicken manure induced a significant increase in phenol content and reduced flavonoid content and the antioxidant activity of the fruit pulp. The chicken manure did not influence the productivity of C. adamantium or the chemical composition of fruits. The use of spacing of 0.35 m between plants and 1.50 m between rows is recommended, with the aim of producing fruits