scholarly journals Effects of selective-logging, litter and tree species on forests in the Peruvian Amazon: seed predation, seed pathogens, germination

2021 ◽  
Vol 51 ◽  
Author(s):  
Randall W. Myster
Keyword(s):  
Seed Predation ◽  
Tree Species ◽  
Amazon Basin ◽  
Field Experiments ◽  
Selective Logging ◽  
Terra Firme ◽  
White Sand ◽  
Sand Forest ◽  
Terra Firme Forest ◽  
Socratea Exorrhiza

Background: The Amazon basin contains mainly unflooded forests, and they are among the most important ecosystems in the world. Field experiments on seed processes are very important in order to understand the structure, function and dynamics of these forests. Methods: And so tree seeds of three species (Cecropia latiloba, Guarea macrophylla, Socratea exorrhiza) were set out in Amazon unlogged terra firme forest, in Amazon selectively-logged terra firme forest, in Amazon palm forest, and in Amazon white sand forest either on top of or beneath the litter layer, and after two weeks scored for seeds taken by predators, seeds destroyed by pathogens and seeds that germinated. Results: I found both terra firme forests (unlogged and selectively-logged) lost most of their seed to predators and the least of their seed to pathogens, white sand forests lost the least of their seed to predators and the most of their seed to pathogens, and the fewest seeds germinated in both terra firme forests and in palm forest. More specifically (1) within unlogged terra firme forest addition of litter reduced seed predation but increased seed losses to pathogens and germination, and C. latiloba lost the most seeds to pathogens, (2) within selectively-logged terra firme forest seeds showed the same trends as unlogged terra firme forest but without significant effects, (3) within palm forest addition of litter reduced predation but increased losses to pathogens, and S. exorrhiza lost the least seeds to pathogens, and (4) within white sand forests addition of litter increased germination. Combining the results from all forests together, predators took most of the seeds, pathogens took most of the seeds that escaped predation, and most of the seeds that survived predation and pathogens germinated. Conclusion: While such large losses of tree seed to predators and pathogens in these unflooded forests suggest limited recruitment, the variation demonstrated in these field experiments – among forest-types, among tree species, between litter situations on the forest floor – help to insure that recruitment does occur and that these unflooded forests continue to dominate the Amazon basin.

scholarly journals Effects of Soil Type on Floristics and Stand Structure in Amazon Unflooded Forests

2018 ◽  
Vol 7 (2) ◽  
pp. 20
Author(s):  
Randall Myster
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Common Species ◽  
Forest Plot ◽  
Terra Firme ◽  
White Sand ◽  
Sand Forest ◽  
Terra Firme Forest ◽  
Structure Lead ◽  
Set Up

The importance of unflooded forests in the Amazon and the need to investigate how their soils affect their floristics and stand structure, lead me to set up and sampled trees in four plots in terra firme forest, in white sand forest and in palm forest at the same site in the Peruvian Amazon. I found (1) the white sand forest plot had 15 families with Clusiaceae, Malvaceae and Myrtaceae the most common and Pachira brevipes the most common species, (2) the palm forest plot had 6 families with Arecaceae, Clusiaceae and Fabaceae the most common and Socratea exorrhiza the most common species, and (3) the terra firme forest plot had 47 families with Myristicacea, Fabaceae and Bombacace the most common and Otoba parvifolia and Astrocaryum murumura the most common species. For the stand structure of these forests, (1) terra firme had more stems and larger stems than white sand and palm, and while palm had more stems than white sand, white sand had larger stems than palm, (2) species richness was greatest in terra firme and decreased by a factor of three in white sand, and by a factor of five in palm, (3) basal area decreased from terra firme to white sand, but white sand and palm were comparable, (4) white sand had the greatest above-ground biomass, followed by terra firme and palm, and (5) white sand and palm were much more open forests than terra firme. Results strongly suggest that soils are a significant causal factor in determining floristic and structural differences among these Amazon forests, where the richer soil of terra firme forest helps produce both more structure and a richer floristics compared to the poor soil of palm forests and the even poorer soil of white sand forests.

scholarly journals Habitat specialization and phylogenetic structure of tree species in a coastal Brazilian white-sand forest

2014 ◽  
Vol 7 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Alexandre A. de Oliveira ◽  
Alberto Vicentini ◽  
Jerome Chave ◽  
Camila de T. Castanho ◽  
Stuart J. Davies ◽  
...  
Keyword(s):  
Tree Species ◽  
Habitat Specialization ◽  
Phylogenetic Structure ◽  
White Sand ◽  
Sand Forest

scholarly journals Vantanea maculicarpa (Humiriaceae): a new tree species from French Guiana

Phytotaxa ◽  
2018 ◽  
Vol 338 (1) ◽  
pp. 130 ◽  
Author(s):  
JULIEN ENGEL ◽  
DANIEL SABATIER
Keyword(s):  
New Species ◽  
Tree Species ◽  
French Guiana ◽  
Similar Species ◽  
Terra Firme ◽  
Terra Firme Forest ◽  
A New Species

A new species of Humiriaceae, Vantanea maculicarpa, growing in French Guiana terra-firme forest is described and illustrated. This new species is distinguished from all other species of Vantanea by fruits covered by white lenticels, a character so far unknown in this genus. It also presents a pubescent intrastaminal disk, a feature encountered in two other Vantanea species only: it is further distinguished from V. parviflora, the morphologically most similar species, by more stamens and from V. ovicarpa by a much smaller rough endocarp with five valves. A key to the species of French Guiana and the IUCN status Least Concern (LC) are proposed.

scholarly journals Estructura y composición florística arbórea en dos tipos de bosque en la Zona de Amortiguamiento, Reserva Nacional de Tambopata

Q'EUÑA ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 39-50
Author(s):  
Sufer Marcial Baez Quispe ◽  
Jorge Santiago Garate Quispe
Keyword(s):  
Species Diversity ◽  
Floristic Composition ◽  
Forest Types ◽  
Terra Firme ◽  
Important Family ◽  
Flooded Forest ◽  
Madre De Dios ◽  
Terra Firme Forest ◽  
Socratea Exorrhiza ◽  
Tierra Firme

Resumén Se presenta un análisis y comparación de la diversidad, estructura y composición florística de dos tipos de bosque (de tierra firme e inundable) en dos concesiones de conservación en la Zona de Amortiguamiento de la Reserva Nacional Tambopata (Madre de Dios, Perú). Se instalaron 2 parcelas de 10 m x 500 m (0,5 ha) por tipo de bosque, donde se inventarió todos los individuos con un diámetro a la altura del pecho (DAP) ≥ 10 cm. Se realizó la caracterización estructural de ambos tipos de bosque, se calculó la diversidad en ellos y se estudió la similitud entre ellos. Los resultados sugieren diferencias entre los dos tipos de bosque en términos de abundancia, dominancia, estructura y composición florística de acuerdo con otros estudios en la Amazonia. La diversidad de especies fue alta en el bosque de tierra firme (α-Fischer 84,4–57,4 y H' 4,0–4,5) y baja en el bosque inundable (α-Fischer 39.9 – 42.4, H' 3.3 – 3.4). Arecaceae fue la familia más importante en los bosques inundables, mientras que Moraceae fue la familia más importante en los bosques de tierra firme. Ficus gomelleira, Pterocarpus amazonum, Hevea guianensis, y Socratea exorrhiza fueron las especies más importantes en los bosques de tierra firme, mientras que Iriartea deltoidea, Otoba parvifolia y Pseudolmedia laevis, fueron las más importantes en los bosques inundables. La composición florística fue diferente entre los dos tipos de bosque, con 19,3 % de similitud en promedio (distancia de Bray-Curtis). Nuestros resultados coinciden con los obtenidos en otras investigaciones para la Amazonía Peruana. AbstractThe aim of this study was to compare and analyze the diversity, structure and floristic composition of two forest types at buffer zone of the Tambopata National Reserve (Madre de Dios). Two plots per forest types of 10 m x 500 m (0.5 ha) were used, where all individuals with a diameter at the breast height DBH ≥ 10 cm were inventoried. The total height (HT) and DBH of all tree individuals were measured. In the structural analysis, DBH size classes, density, dominance, and the importance index were calculated. We calculated the Shannon-Weaver index, α-Fischer index, and Bray-Curtis distance to evaluate the species diversity and similarity between the two forest types. The results suggest differences between forest types in terms of abundance, dominance, structure and floristic composition in agreement with other studies in the Amazonia. The species diversity is higher the terra firme forest (α-Fischer 84.4–57.4 y H' 4.0–4.5) than in the flooded forest (α-Fischer 39.9 – 42.4 y H' 3.3 – 3.4). The Arecaceae was the most important family in the flooded forest while the Moraceae was the most important family in terra firme forest. Ficus gomelleira, Pterocarpus amazonum, Hevea guianensis, and Socratea exorrhiza were the most important species in terra firme 

Importance of topography for tree species habitat distributions in a terra firme forest in the Colombian Amazon

2018 ◽  
Vol 450 (1-2) ◽  
pp. 133-149 ◽  
Author(s):  
Daniel Zuleta ◽  
Sabrina E. Russo ◽  
Andrés Barona ◽  
Juan S. Barreto-Silva ◽  
Dairon Cardenas ◽  
...  
Keyword(s):  
Tree Species ◽  
Terra Firme ◽  
Terra Firme Forest ◽  
Colombian Amazon

scholarly journals Updated List and identification key of 219 tree species of white sand forests of the Allpahuayo Mishana National Reserve, Loreto, Peru

2015 ◽  
Vol 45 (2) ◽  
pp. 133-156
Author(s):  
Ricardo ZARATE GOMEZ ◽  
Tony Jonatan MORI VARGAS ◽  
Fredy Francisco RAMIREZ AREVALO ◽  
Hilda Paulette DAVILA DOZA ◽  
George Pepe GALLARDO GONZALES ◽  
...  
Keyword(s):  
Endemic Species ◽  
Tree Species ◽  
Abundant Species ◽  
Identification Key ◽  
White Sand ◽  
Comprehensive List ◽  
Dichotomous Key ◽  
Sand Forest

White sand forests, although low in nutrients, are characterized not only by several endemic species of plants but also by several monodominant species. In general, plants in this forest have noticeably thin stems. The aim of this work was to elaborate a parallel dichotomous key for the identification of Angiosperm tree species occurring on white sand forests at the Allpahuayo Mishana National Reserve, Loreto, Peru. We compiled a list of species from several publications in order to have the most comprehensive list of species that occur on white sand forest. We found 219 species of Angiosperm, the more abundant species were Pachira brevipes (26.27%), Caraipa utilis (17.90%), Dicymbe uaiparuensis (13.27%), Dendropanax umbellatus (3.28%), Sloanea spathulata (2.52%), Ternstroemia klugiana (2.30%), Haploclathra cordata (2.28%), Parkia igneiflora (1.20%), Emmotum floribundum (1.06%), Ravenia biramosa (1.04%) among others. Most species of white sand forests can be distinguished using characteristics of stems, branches and leaves. This key is very useful for the development of floristic inventories and related projects on white sand forests from Allpahuayo Mishana National Reserve.

scholarly journals White-Sand Savannas Expand at the Core of the Amazon After Forest Wildfires

Ecosystems ◽  
2021 ◽  
Author(s):  
Bernardo M. Flores ◽  
Milena Holmgren
Keyword(s):  
Tree Species ◽  
Amazon Basin ◽  
Forest Tree ◽  
Landsat Images ◽  
Tree Species Composition ◽  
White Sand ◽  
The Core ◽  
Ecosystem Shift ◽  
Seasonally Flooded ◽  
Satellite Analysis

AbstractAcross the tropics, climate change is increasing the frequency and severity of wildfires, exposing tropical forests to the risk of shifting into an open vegetation state. A recent satellite analysis of the Amazon basin suggests this might happen first in floodplains where forests are particularly fragile. We studied floodplain landscapes of the middle Rio Negro, covering ~ 4100 km2 at the Central Amazon region, where forest ecosystems are dominant. We used Landsat images to map 40 years of wildfire history and test the hypothesis that repeatedly burnt forests fail to regenerate and can be replaced by white-sand savanna ecosystems. In the field, using a chronosequence of ‘time after the first fire’, we assessed changes in tree species composition, herbaceous cover and topsoil properties. Here we show that when these forests are repeatedly disturbed by wildfires, their soil gradually loses clay and nutrients and becomes increasingly sandy. In synchrony, native herbaceous cover expands, forest tree species disappear and white-sand savanna tree species become dominant. This drastic ecosystem shift happened within 40 years, likely accelerated by topsoil erosion. When recurrent fires maintain floodplain forests in an open vegetation state, topsoil erosion intensifies, transforming clay-rich soils into white-sand soils that may favour savanna tree species. Our findings reveal that white-sand savannas may expand through seasonally flooded ecosystems at the core of the Amazon, facilitated by wildfires.

scholarly journals Tree communities of white-sand and terra-firme forests of the upper Rio Negro

2011 ◽  
Vol 41 (4) ◽  
pp. 521-544 ◽  
Author(s):  
Juliana Stropp ◽  
Peter Van der Sleen ◽  
Paulo Apóstolo Assunção ◽  
Adeilson Lopes da Silva ◽  
Hans Ter Steege
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Large Scale ◽  
Species Abundance ◽  
Tree Diversity ◽  
Terra Firme ◽  
Floristic Similarity ◽  
White Sand ◽  
Rio Negro ◽  
Tree Communities

The high tree diversity and vast extent of Amazonian forests challenge our understanding of how tree species abundance and composition varies across this region. Information about these parameters, usually obtained from tree inventories plots, is essential for revealing patterns of tree diversity. Numerous tree inventories plots have been established in Amazonia, yet, tree species composition and diversity of white-sand and terra-firme forests of the upper Rio Negro still remain poorly understood. Here, we present data from eight new one-hectare tree inventories plots established in the upper Rio Negro; four of which were located in white-sand forests and four in terra-firme forests. Overall, we registered 4703 trees > 10 cm of diameter at breast height. These trees belong to 49 families, 215 genera, and 603 species. We found that tree communities of terra-firme and white-sand forests in the upper Rio Negro significantly differ from each other in their species composition. Tree communities of white-sand forests show a higher floristic similarity and lower diversity than those of terra-firme forests. We argue that mechanisms driving differences between tree communities of white-sand and terra-firme forests are related to habitat size, which ultimately influences large-scale and long-term evolutionary processes.

scholarly journals Orchid bees in riparian and terra-firme forest fragments in an urban matrix in southwestern Brazilian Amazonia

2021 ◽  
Vol 51 (3) ◽  
pp. 214-223
Author(s):  
Maria Eliene Maia Braga CÂNDIDO ◽  
Patrícia Nakayama MIRANDA ◽  
Elder Ferreira MORATO
Keyword(s):  
Species Richness ◽  
Amazon Basin ◽  
Urban Landscape ◽  
Riparian Forests ◽  
Forest Fragments ◽  
Terra Firme ◽  
Orchid Bees ◽  
Significant Difference ◽  
Terra Firme Forest ◽  
Species Richness And Abundance

ABSTRACT Riparian forests are important ecosystems that support an enormous biodiversity in Brazil. Despite being protected under Brazilian legislation, these forests suffer great impact from the fragmentation of habitats. Orchid bees are a key group of pollinators in the Neotropical region, yet few data are available on the assamblage structure of these bees in riparian forests. We evaluated the role of fragments of riparian and terra-firme forest on the conservation and maintenance of orchid bees in an urban landscape in the southwestern Amazon basin. Specifically, we evaluated whether bee assemblages in riparian and terra-firme forests differed significantly in abundance, species richness and composition. We also evaluated whether species richness and abundance of bees vary with the size of the forest fragment. Male bees were attracted using odoriferous baits and collected with entomological nets in 10 forest fragments. There was no significant difference between riparian and terra-firme fragments in species abundance, richness and composition, but there was a positive correlation between fragment size and species richness and abundance. Our results suggest that, in an urban landscape, the remaining riparian and terra-firme forest fragments still could maintain 62.7% of the orchid bee species known to occur in the region, reinforcing the conservation value of these forest remnants. Our findings indicate that these fragments provide a potentially important habitat for the maintenance of local bee populations in the landscape.

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