Domingos Cardoso

Summary: Dalechampia parvopseudantha (Euphorbiaceae), a new species with the smallest pseudanthium (2 – 2.5 cm long) within Dalechampia sect. Tiliifoliae , is described from the Atlantic Forest of Espírito Santo state in southeastern Brazil. The species is further distinguished by a combination of a 5 – 6 mm long peduncle; involucral bracts 1 – 1.5 × 0.7 – 0.8 cm, slightly 3-lobed, oblanceolate, yellowish-green, with a tomentose surface; staminate flowers with three broadly lanceolate sepals; sepals of pistillate flowers bearing conspicuous glandular trichomes and a stylar column with a slightly lobed apex. This unique set of morphological features readily distinguishes D. parvopseudantha from all other species of Dalechampia sect. Tiliifoliae , which is widely known to bear relatively large, up to 6.5 cm long pseudanthium. A full description, illustrations, field photographs, distribution map, phenology, habitat and a preliminary conservation status assessment are provided, as well as a table comparing the new species with its morphologically related, congeneric species. The striking size reduction of the pseudanthium discovered in a genus long used as a model for pollination biology, suggests that key ecologically informative variation may remain undocumented even in comparatively well-studied lineages.

Accurate mapping of woody biomass and its temporal change is critical for understanding the global carbon balance, informing restoration and supporting evidence‐based policy on climate mitigation and livelihoods. The vegetation of the dry tropics, comprised largely of dry forests and savannas, holds substantial woody carbon stocks, but both stocks and change over time remain uncertain. Where Earth Observation (EO) data have been used to estimate change over time, different products give conflicting results on the direction, magnitude and location of change. We present pan‐dry‐tropical maps of aboveground carbon density (AGCD) and AGCD change at 100 m resolution for the years 2015–2024, developed using ALOS ScanSAR satellite radar observations calibrated with in situ measurements ( n = 237). These maps suggest an aboveground woody carbon pool (AGC) in the dry tropics of 25.3 2.0 PgC, ~13.0% of global AGC. Net AGC has increased by 0.43 0.07 PgC yr ⁻¹ , ~20.0% of the global net land sink. The overall net increase (0.43 PgC yr ⁻¹ ) is comprised of gross losses from deforestation and degradation (0.27 0.05 PgC yr ⁻¹ ) and gains due to densification and extensification of 0.59 0.1 PgC yr ⁻¹ , with the balance accounted for by small changes (change < 20% of AGCD; 0.11 PgC yr ⁻¹ ). Losses are equally split between degradation and deforestation, while gains are divided roughly 2:1 between the densification of woody ecosystems and expansion into previously grass‐dominated areas. These new maps, created with a dry‐tropics‐specific EO method, highlight the importance of tropical dry forests and savannas in the global carbon cycle. The prominent role of degradation‐related losses suggests that climate change mitigation will need to focus much more on reducing losses from overharvesting than at present. The widespread increases in carbon density and the increase in tree biomass into open systems present major challenges for biodiversity conservation, restoration and livelihoods.

Species extinction-risk assessments are central to conservation planning, yet frequently lack quantitative evidence of historical land-cover change relevant to habitat conditions within species distributions. Here, we integrate long-term land-use and land-cover (LULC) time series from MapBiomas with IUCN Red List assessments to quantify historical LULC dynamics relevant to habitat conditions across the distributions of 1,036 Brazilian legumes (Leguminosae), of which 915 are endemic. We operationalize the ’continuing decline’ of IUCN Criterion B using LULC-derived regression slopes, transforming a traditionally qualitative judgment into a measurable, reproducible metric, and estimate the number of locations using a buffer-based spatial method. Net loss of natural cover consistently outweighs gains—a pattern more pronounced in extent of occurrence (EOO; losers-to-winners ratio: 2.61) than in area of occupancy (AOO; ratio: 1.13)—supporting a ’few winners and many losers’ dynamic. EOO natural land cover decline rates are significantly higher among non-threatened than threatened species, with Least Concern species showing the highest rates of large-scale land-cover change within their distributions, whereas AOO trends show little differentiation across threat categories. Applied to 218 threatened species assessed exclusively under Criterion B for which expert location counts were available, the automated framework produced predominantly conservative outcomes, with category downgrades consistently outnumbering upgrades across all buffer radii. Nevertheless, a small but consistent set of upgrades identified species whose current categories may underestimate extinction risk. We conclude that annual LULC data enable rapid and consistent detection of extinction-risk signals across large taxonomic groups, supporting scalable and transferable evidence-based approaches to conservation prioritisation in megadiverse regions.

Premise: Advances in the digitization of herbarium collections are enabling open access to specimen data for research and conservation. In Brazil, the Herbário Virtual Reflora (HVR) hosts over 4.8 million high‐resolution images of botanical specimens and their associated data from 86 national and international herbaria. Methods and Results: To facilitate access and use of HVR data in biodiversity research, we developed the R package refloraR. This tool interacts with the HVR Integrated Publishing Toolkit (IPT) to download, parse, summarize, and filter herbarium records in Darwin Core Archive (DwC‐A) and dataframes. It also retrieves occurrence records and indeterminate specimens for any hierarchical level. We provide a working example that combines the refloraR functions for quantifying indeterminate specimens as an indicator of taxonomic gaps within and among collections. Conclusions: The refloraR package supports reproducible workflows in systematics, conservation, and ecology. By enabling the efficient retrieval of specimen data, it integrates the HVR into modern biodiversity informatics and democratizes access to natural history collections.

Societal Impact Statement: Biodiversity science depends on more than collecting plants—it depends on how we search for them. Although GPS and digital maps have transformed fieldwork, they can also encourage repeated visits to the same easy‐to‐access sites, leaving other habitats and populations unknown to science. This paper formalizes “niche‐tracking,” a well‐known practical approach in which botanists combine scientific knowledge with traditional and local ecological knowledge to track the conditions where target plants are most likely to occur. By making this search strategy explicit and reportable, we improve transparency in biodiversity data and increase the chances of finding new populations—especially for rare, threatened, or poorly known species. Summary: Botanical collecting protocols are highly standardized for specimen preparation, labeling, and curation, yet the search strategy used to locate target taxa is often reported vaguely. In practice, taxon‐focused fieldwork rarely samples at random. Collectors rely on prior ecological knowledge from floras and taxonomic treatments, herbarium labels, personal field experience, and increasingly digital maps, as well as traditional and local ecological knowledge. Here, we define and name this tacit approach as “niche‐tracking,” a field collecting method in which botanists intentionally track the multidimensional ecological niche of a taxon—integrating abiotic and biotic dimensions—to decide where and when to search. By prioritizing habitat space rather than repeatedly revisiting the same georeferenced localities (“GPS‐chasing”), niche‐tracking can broaden the environmental and geographic scope of collecting effort and increase the likelihood of bring to light additional populations still unknown to science, which is especially valuable for rare, threatened, or poorly known taxa. We clarify that niche‐tracking is not ecological niche modeling: It is a flexible field methodology that can complement quantitative models while leveraging niche dimensions that models often under‐represent. We also discuss when niche‐tracking improves collecting efficiency and botanical documentation.

Questions: Seasonally dry tropical forests are widespread globally and can store large quantities of carbon, yet they remain underrepresented in spatial assessments compared with humid tropical forests. The Caatinga biome in northeastern Brazil has experienced centuries of wood extraction and land‐use expansion, reducing its current biomass below ecological potential. We asked: (i) how do climatic, atmospheric, and topographic gradients regulate the spatial distribution of aboveground biomass? and (ii) where does the biome maintain a high potential for carbon storage under current environmental conditions? Location: Caatinga biome, northeastern Brazil. Methods: We compiled data from 301 georeferenced forest inventory plots and integrated them with high‐resolution climatic, atmospheric, and topographic predictors. We used principal component analysis to identify major environmental gradients and fitted a spatially validated random forest model to estimate the potential aboveground biomass across the biome. Model performance was evaluated using both random and spatial cross‐validation. Results: Two nearly orthogonal environmental gradients emerged: a hydrothermal gradient associated with precipitation, temperature, and drought severity, and a topographic gradient associated with slope, terrain ruggedness, and landform position. The spatial model explained substantial variation in biomass potential ( R ² = 0.81; RMSE = 21 Mg ha ⁻¹ ). Biomass potential increased markedly when drought severity was lower (maximum cumulative water deficit less negative than −500 mm) and annual precipitation exceeded approximately 1100 mm, while higher vapor pressure deficit and potential evapotranspiration were associated with reduced biomass potential. Rugged and concave terrain supported more than twice the aboveground biomass found in flat or convex sites. Conclusions: The Caatinga is not a uniformly low‐biomass system but a heterogeneous landscape containing localized high‐biomass refugia shaped by the interaction of water availability, atmospheric demand, and terrain complexity. By estimating potential biomass, this work provides a baseline to guide ecological restoration, conservation planning, and climate mitigation strategies in tropical drylands.

Aim: We investigate the distribution of dispersal modes — endozoochory (via animal ingestion), synzoochory (via animal seed accumulation) and anemochory (via wind)—and seed mass of woody plants across Brazilian ecosystems, testing whether their relative abundance in local plant communities could be predicted by climate, edaphic factors and dispersal agents (e.g., the main vectors moving seeds). We expected climate to be the main predictor of dispersal strategy abundance. Location: Brazilian ecosystems (Amazon, Atlantic Forest, Cerrado and Caatinga). Time Period: 2004–2020. Major Taxa Studied: Woody angiosperms, trees and shrubs. Methods: We assigned seed mass to 1984 species and dispersal mode to 2203 species within 300 old‐growth and non‐flooded plots. We employed Random Forest regressions to assess the influence of water availability, temperature seasonality, soil fertility, wind and frugivorous primates on the community‐weighted means of seed mass and dispersal modes. We mapped predictions and estimated the area of applicability to identify regions where predictions were reliable. Results: Climate was the main factor predicting tree dispersal strategies, followed by dispersal agents or soil properties. Endozoochory was prevalent in wetter regions with high water availability and greater diurnal temperature range. Anemochory was more common in drier regions with low water availability, stronger winds and greater diurnal temperature range, whereas synzoochory was more abundant in areas with low temperature seasonality. Heavier seeds were more prevalent in regions with less seasonal temperatures, smaller diurnal temperature ranges and weaker winds. Main Conclusions: Climate is a key predictor of the distribution and prevalence of plants with contrasting dispersal modes and seed masses. We thus expect functional responses to environmental change associated with shifts in the relative abundance of dispersal strategies, with implications for ecosystem services. Our results also highlight the critical role of plot‐based datasets in improving our understanding of how environmental factors influence seed dispersal strategies across tropical ecosystems.

Lianas are a key component of the Neotropical flora, accounting for 10% of angiosperm richness and playing important ecological roles. However, the canopy preference of some species often leads to their underrepresentation in herbarium collections, thereby exacerbating Linnaean, Darwinian, and Wallacean shortfalls. The papilionoid legume genus Macropsychanthus exemplifies this challenge, with 37% of its species documented from 10 or fewer herbarium collections. In this study, we describe two new species represented by only one or two collections made during the early to mid‐20th century and assess their phylogenetic position within the genus. Additionally, we compiled a preliminary list of Brazilian legume liana species documented from five or fewer collections and modeled their potential niche distributions to assess whether these species could be distributed more broadly. We identified a total of 55 liana species with five or fewer collections, representing 20% of Brazilian legume liana species. Of these, 28 species are from the Amazon, 23 from the Atlantic Forest, 2 from the Cerrado and 2 from the Caatinga. Species from the Amazon, Caatinga, and Cerrado tend to have broader potential distributions across their respective biomes, whereas those from the Atlantic Forest are generally more narrowly restricted. Our findings highlight the urgent need for comprehensive botanical surveys in Neotropical humid forests to address critical knowledge gaps in plant diversity.

We describe a new species of the papilionoid legume genus Aeschynomene (Leguminosae, Papilionoideae) that is tightly ecologically associated with Amazonian campos rupestres on iron-rich canga soils of the Serra dos Carajás mountain range, Pará, Brazil. The new species is morphologically similar to Aeschynomene rudis, but it differs by the smaller leaflets, larger flower, glabrous ovary, and a longer and sigmoid fruit stipe. We present a complete description, taxonomic comments, illustrations, and a distribution map for the new species. Additionally, we provide its phylogenetic position and an identification key to all Aeschynomene and Ctenodon species occurring on the canga of the Serra dos Carajás.