Browsing by Autor "Daniel P. Soto"

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Differing local‐scale responses of Bolivian Amazon forest ecotones to middle Holocene drought based upon multiproxy soil data
(Wiley, 2023) James Hill; Stuart Black; Daniel P. Soto; Ezequiel Chavez; Vincent Antoine Vos; Francis Mayle
ABSTRACT Uncertainty remains over local‐scale responses of ecotonal Amazonian forests to middle Holocene drying due to the scarcity, and coarse spatial resolution, of lacustrine pollen records. This paper examines the palaeoecological potential of soil phytoliths, stable carbon isotopes and charcoal for capturing local‐scale ecotonal responses of different types of Bolivian Amazonian forest to middle Holocene climate change. Soil pits 1 m deep were dug at ecotones between rainforest, dry forest, Chaco woodland and savannah, and sampled at 5–10 cm resolution. Both phytolith and stable carbon isotope records indicate stability of dry forest–savannah ecotones over the last ca. 6000 years, despite middle Holocene drought, revealing the dominance of edaphic factors over climate in controlling this type of ecotone. In contrast, δ 13 C data reveal that rainforest–savannah ecotones were more responsive to climate change, with rainforest likely replaced by drought‐tolerant dry forest or savannah vegetation during the mid‐Holocene, consistent with regional‐scale lacustrine pollen records. However, such shifts are not apparent in most of our phytolith records due to insufficient taxonomic resolution in differentiating rainforest from dry forest. Charcoal data show that ecotonal dry forests experienced greater fire activity than rainforests and that recent high fire activity at all forest sites is unprecedented since at least the middle Holocene.
Dos especies nuevas de Borreria (Rubiaceae), un nuevo registro de Declieuxia y observaciones taxonómicas
(Springer Science+Business Media, 2011) Roberto M. Salas; Daniel P. Soto; Elsa L. Cabral
Foraging Behavior of Criollo vs. Brahman × Criollo Crossbreds in the Bolivian Chaco: Case Study
(Elsevier BV, 2018) Svenja Marquardt; Daniel P. Soto; N. Joaquín
Non-woody life-form contribution to vascular plant species richness in a tropical American forest
(2008) Reynaldo Linares‐Palomino; Víctor Manuel Pardo Cardona; Ernest I. Hennig; Isabell Hensen; Doreen Hoffmann; Jasmin Lendzion; Daniel P. Soto; Sebastián K. Herzog; Michael Kessler
We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions.
Non-woody life-form contribution to vascular plant species richness in a tropical American forest
(Springer Science+Business Media, 2008) Reynaldo Linares‐Palomino; Víctor Manuel Pardo Cardona; Ernest I. Hennig; Isabell Hensen; Doreen Hoffmann; Jasmin Lendzion; Daniel P. Soto; Sebastián K. Herzog; Michael Kessler
We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions.
RECONSTRUCTING PRE-COLOMBIAN AGRICULTURAL PRACTICES IN THE BOLIVIAN SAVANNAH: STRATIGRAPHIC AND PHYTOLITH EVIDENCE FROM RAISED FIELDS AT CAMPO ESPAÑA, WESTERN LLANOS DE MOXOS
(Federal University of Pelotas, 2016) Ruth Dickau; José Iriarte; Timothy A. Quine; Daniel P. Soto; Francis Mayle
Abstract: Pre-Columbian inhabitants of the western Llanos de Moxos, Bolivia, transformed large expanses of seasonally flooded savannah into a complex agricultural landscape. Extensive raised field systems, along with associated canals and causeways, suggest a sophisticated approach to managing land and water resources for permanent, intensive, agricultural production. However, the detailed construction history, specific crops, and palaeoenvironmental impacts of these fields are poorly known. To investigate these issues, we analyzed stratigraphy and phytoliths from two raised fields (camellones) at the site of Campo España, western Beni, Bolivia. Results indicate that prior to field construction, vegetation was mainly palm savannah. A decline in arboreal phytolith frequencies is associated with human clearing and initial field construction. A peak in burnt grass phytoliths followed by an increase of Asteraceae, suggests a period of regular field maintenance and intensive agricultural use. Maize (Zea mays) and manioc (Manihot esculenta) were grown. A small increase in arboreal phytoliths suggests some forest recovery after field abandonment. This study demonstrates the utility of phytolith and stratigraphic analyses in reconstructing construction, cultivation, and palaeoenvironmental histories of raised field systems, and assessing their role within the advanced agricultural landscape management practiced by pre-Columbian populations in the Bolivian Amazon. Resumo: Os habitantes pré-colombianos de Llanos de Moxos ocidental, Bolívia, transformaram grandes áreas de uma savana sazonalmente inundada em complexas paisagens agrícolas. Extensos campos de plantação, assim como canais e caminhos associados, sugerem uma abordagem sofisticada para o manejo da terra e dos recursos aquáticos para produção agrícola intensiva e permanente. No entanto, detalhes sobre suas histórias construtivas, plantações específicas e os impactos paleoambientais destes campos são pouco conhecidos. Para investigar estas questões, analisamos a estratigrafia e os fitólitos de dois destes campos elevados (camellones) do sítio Campo España, oeste de Beni, Bolívia. Os resultados indicam que antes da construção dos campos, a vegetação era majoritariamente uma savana com palmeiras. O declínio na frequência de fitólitos arbóreos é associado com uma limpeza da área pela ação humana e o início das construções dos campos. Um pico nos fitólitos de grama queimada seguido porum aumento de Asteraceae, sugere um período de manutenção regular dos campos e uso agrícola intensivo. Eram cultivados milho (Zea mays) e possivelmente mandioca (Manihot esculenta). Um pequeno aumento dos fitólitos arbóreos sugere certo grau de recuperação da floresta após o abandono dos campos. Este estudo demonstra a utilidade de análises de fitólitos e estratigráficas na reconstrução dos processos de construção, cultivo e história paleoambiental dos sistemas de campos elevados e na avaliação de seus papeis dentro do avançado manejo de paisagens agrícolas praticadas por populações pré-colombianas na Amazônia boliviana.