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Summary: Wood anatomy and dendrology of quebracho lagunero Aspidosperma triternatum (Apocynaceae). The aim of present study is describe the dendrology and the secondary xylem of A. triternatum N. Rojas, Apocynaceae, an endemic tree of Humid Chaco of Argentina and Paraguay. The samples came from Ingeniero Juarez in Formosa. Wood and bark samples of 5 mature individuals were taken at 1,30 m height. The terminology of wood anatomical characters follows the recommendations of the IAWA Committee. External bark of A. triternatum is scaly with irregular, right-angled or isodiametric scales, and deep fissures with rounded ridges. The Wood is white- yellow to dark-yellow, without sapwoodheartwood distinction. The grain is oblique to interlock and fine textured. Growths rings boundaries are scarcely marked by thick-wall and radially flattened fibers. The wood is diffuse-porous not uniform, with numerous solitary vessels with elliptic outline. The axial parenchyma is apotracheal diffuse to reticulate. The rays are numerous mostly triseriates and homocellular, occasionally aggregates rays present. The fibers and fiber tracheids are medium with thick walls and distinctly bordered pits in some sectors. Wood anatomy structure of Aspidosperma triternatum follows the general pattern of the family Apocynaceae, and shows similar characteristics of the others Aspidospermas of Argentina.
This review systematically analyzes the scientific literature on interactions among ecosystem services (ES) in the territory of the American Gran Chaco, covering its three constituent ecoregions (Dry, Humid, and Serrano), over the last 24 years (2001–2025). The objective is to synthesize the current state of knowledge by: (a) identifying the main documented trade-offs and synergies; (b) characterizing the analytical approaches and methods used; (c) determining the main drivers of ES interactions; and (d) identifying knowledge gaps and research priorities for more integrated and sustainable landscape management. Our analysis of 106 studies reveals that ES research in the Chaco is a growing and diversifying field of study. Although biophysical approaches have historically dominated (49
Context Consumption of water with high sulfate concentrations can negatively affect on feed intake in beef cattle. However, limited information is available on how water quality interacts with diets differing in digestibility. Aim This study evaluated the interaction between a broad range of diet quality (DQ) and water quality (WQ) on feed and water intake (WI), total tract digestibility, nitrogen (N) metabolism, and ruminal hydrogen sulfide (H2S) production in beef heifers. Method Eight Braford-crossbred heifers (326 ± 34 kg BW) were used in an eight-treatment crossover design combining two types of WQ, namely, low-sulfate water (LSW; 333 mg/L sulfate, SO4) and high-sulfate water (HSW; 3286 mg/L, SO4) with four DQ of low (LQ), medium–low (MLQ), medium–high (MHQ), and high (HQ). Key results A significant DQ × WQ interaction was observed for WI (P = 0.04), digestible organic matter (OM) intake (DOMI; P = 0.01), and digestible neutral detergent fiber (NDF) intake (DNDFI; P < 0.01). Diet quality had a quadratic effect on both water (P = 0.02) and feed intake (P < 0.01), with the highest values occurring at intermediate levels of digestibility. High-sulfate water reduced WI (P < 0.01), OM intake (OMI; P < 0.01), and NDF intake (NDFI; P < 0.01). In heifers consuming HSW, DOMI tended to be lower at the highest DQ (HQ; P = 0.07), with lower values also observed at intermediate DQ levels (MLQ and MHQ; P < 0.01). Water quality improved and tended to enhance total tract NDF (P = 0.03) and OM digestibility (P = 0.06) respectively. High-sulfate water also increased ruminal H2S concentrations (P < 0.01). Conclusions The results of this study demonstrated an interaction between diet and water quality affecting feed intake in beef heifers. Implications Improving diet quality may help mitigate the negative effects of high sulfate-containing water on feed intake. Additionally, incorporating highly digestible NDF into the diet appears to be a viable strategy to maintain ruminal H2S concentrations below toxic thresholds.
Aim of study: To assess the effects of forest disturbances on two foliar attributes, leaf area (LA) and specific leaf area (SLA), of woody species in a semi-arid Chaco forest of Argentina. Disturbances are represented as different combinations of land management practices (removal of vegetation, logging, and fire). We evaluated intraspecific variation in LA and SLA of six native woody species using a quantitative approach. We also explored the effect of growth form (tree/shrub) and leaf periodicity (perennial/deciduous) on plant responses to disturbances, considering that these traits may determine variations in their behavior in response to such disturbances. Area of study: Subtropical semi-arid Chaco, Santiago del Estero Province, Argentina, South America. Material and methods: Leaves of mature individuals were measured in forests with three different land management histories: undisturbed for four decades (RC); rolled and subjected to selective wood extraction eight years before sampling (Rch+L); and rolled and followed by fire eight years before sampling (Rch+F). For each site, we measured 10 mature individuals of each of the six species studied, recording the maximum height and diameter at breast height (DBH), and harvested 20 leaves from each to measure leaf area (LA) and specific leaf area (SLA). Main results: All species significantly increased their LA and SLA in disturbed forests. Tree species had larger LA than shrubs, while shrubs exhibited higher SLA. Both traits presented higher values in deciduous species compared to perennial species, indicating that, after disturbances, these species could better capture released resources by increasing their foliar area. The community-weighted mean (CWM) of LA was highest in the Rch+L forest, likely reflecting the effect of increased light availability. Additionally, all disturbed forests showed a higher CWM of SLA. Research highlights: The changes observed in leaf traits at the species level, such as higher LA and SLA, which result in higher LA and SLA at the community level, suggest the adoption of more acquisitive strategies in disturbed communities, promoting higher resource capture and facilitating leaf tissue recovery. This may influence ecosystem functions, such as litter decomposition, productivity, and resource allocation for growth and reproduction. Monitoring foliar responses to disturbances in Chaco forests is critical for guiding sustainable management and conservation practices.
Commodity agriculture is rapidly expanding worldwide, often at the expense of natural environments and smallholder agricultural systems. In this paper, we unpack the process of smallholder displacement due to the expansion of agricultural commodity frontiers in the Argentine Chaco, where large-scale soy and cattle operations are advancing over forests used by small-scale herders. We identify a series of trends related to the agricultural frontier - growing pressures on local livelihoods, changing mobility patterns, shifting strategies of land control, and weakening of organized resistance - that conspire to create unstable conditions for families. We find that, in this context, the process of displacement is often brought to term when communities experience a shock that catalyzes a cycle of permanent out-migration, leading to a relatively sudden dissolution of rural communities. In examining the unfolding of displacement over time, rather than treating it as a single event, our study draws attention to the non-linear nature of the process, showing how it is slow until sometimes it is not.
