scholarly journals Ecology of the Seed Bank in the Amazon Rainforest

2021 ◽  
Author(s):  
Natali Gomes Bordon ◽  
Niwton Leal Filho ◽  
Tony Vizcarra Bentos
Keyword(s):  
Land Use ◽  
Tropical Forests ◽  
Seed Bank ◽  
Floristic Composition ◽  
Life Forms ◽  
Amazon Rainforest ◽  
Seed Density ◽  
Forest Resilience ◽  
Identification Of Species ◽  
Successional Trajectory

The seed bank is directly related to forest resilience because it contributes to the greatest number of regenerants after the occurrence of disturbances. Changes in seed density, floristic composition, and life forms completely alter the successional trajectory of forest environments. These changes are directly related to land use. For example, suppression of the seed bank can occur in pastures, that experience frequent fires with increase of density of seeds and predominance of herbs are typical of highly degraded areas, such as Poaceae, Rubiaceae, Asteraceae, and Cyperaceae. Melastomataceae seedlings are an important component of the seed bank in the Amazon rainforest. On the other hand, Urticaceae has greater representation in forests that exhibit low-impact land use. Any change in seed bank functionality is bound to compromise the diversity, regeneration potential and overall maintenance of tropical forests. Therefore, it is necessary to expand studies that investigate seed banks in the Amazon rainforest. It is as important to prioritize sampling methods and pursue standardization of data presentation, as well as improve the identification of species that occur in the seed bank.

scholarly journals Floristic composition of the Montane Forest in the Almadina-Barro Preto axis, Southern Bahia, Brazil

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Macielle Macedo Coelho ◽  
André Márcio Amorim
Keyword(s):  
Species Richness ◽  
Tropical Forests ◽  
Atlantic Forest ◽  
Floristic Composition ◽  
Woody Species ◽  
Life Forms ◽  
Montane Forest ◽  
Forest Remnants ◽  
Southern Bahia ◽  
Arboreal Habit

The aim of this study is to survey the angiosperms of two montane forest remnants in the southern Bahia, Brazil: Corcovado (SCO) and Pedra Lascada (SPL). Both fragments are located in the municipality of Almadina and Barro Preto, respectively, and are 18 km distant from each other. We sampled 899 species of angiosperms distributed in 437 genera and 116 families. The SCO was the richest area with 678 species, distributed in 367 genera and 100 families. SPL showed 466 species in 269 genera and 88 families. The percentage of species identified was 85.8% and of this total, 37.7% are endemic to the Atlantic Forest, 11.2% are endemic to southern Bahia and northern Espírito Santo and 7% are disjunct between the Atlantic Forest and Amazon. The remaining percentages (44.3%) were of species widely distributed. The richest families in the two areas were Orchidaceae (10%), Rubiaceae (7%), Bromeliaceae (5.5%), Melastomataceae (4.2%) and Poaceae (4%). The richest genera were Psychotria (2%),Piper (1.8%), Ocotea (1.6%),Vriesea (1.5%) and Peperomia (1.4%). More than half of the recorded species showed non-arboreal habit, regarding life forms documented. That comes against the assertion that many authors in the tropical forests, where species richness in angiosperms is expected for non-woody species, especially in montane forests. Twelve species have been identified as new, but seven others already described from collections previously obtained in these two areas. Orchidaceae, Rubiaceae, Poaceae and Bromeliaceae showed significant richness in this study these families are commonly reported as the richest in other inventories in the Atlantic Forest in southern Bahia reinforcing their importance to the regional flora. The high levels of richness, endemism, and the growing numbers of new taxonomic discoveries from the SPL and SCO sites indicate the biological importance of these two forest remnants. The implementation of parks or other protected environmental reserves would be essential to the conservation of its species.

Effect of hydroperiod on seed-bank composition in semipermanent prairie wetlands

1989 ◽  
Vol 67 (3) ◽  
pp. 856-864 ◽  
Author(s):  
Karen A. Poiani ◽  
W. Carter Johnson
Keyword(s):  
Seed Bank ◽  
Floristic Composition ◽  
Open Water ◽  
Seed Density ◽  
Prairie Wetlands ◽  
Water Zone ◽  
Significant Difference ◽  
Total Seed ◽  
Frequent Exposure

Bottom samples were collected from two semipermanent prairie wetlands to determine if known hydroperiod differences were reflected in seed-bank composition. Samples were also taken a 2nd year in one wetland to assess between-year variation. Seed density and composition were determined by counting and identifying seedlings that emerged from samples placed in a greenhouse. Most seed-bank characteristics were statistically indistinguishable between wetlands, including floristic composition and total seed density. A significant difference occurred, however, in the relative importance of mudflat annuals and émergents. The mudflat group was much more abundant in the wetland with the shorter hydroperiod (82 vs. 51%). More frequent exposure of the substrate probably yielded greater seed production. Also, a longer hydroperiod depressed seed density in the open water zone (open water zone, 1309 seeds/m2; two emergent zones, 2840 and 9893 seeds/m2). A seed-bank assay may detect subtle hydroperiod differences among wetlands of the same permanence class more quickly and economically than long-term hydrological monitoring. A sharp increase in mudflat seeds in the 2nd year of sampling after a drawdown supports the use of seed banks in determining hydroperiod events in these wetlands.

scholarly journals Features of the floristic composition of the reserve «Khau Ca» Vietnam. and her analysis

2019 ◽  
Author(s):  
В.З. Фан ◽  
А.Ф. Потокин
Keyword(s):  
Tropical Forests ◽  
Negative Impact ◽  
Structural Complexity ◽  
Floristic Composition ◽  
Basic Research ◽  
Life Forms ◽  
Self Healing ◽  
The Face ◽  
Plant Families ◽  
Technical Solutions

Структурная сложность тропических лесов обеспечивает их устойчивость, способность к развитию и выживанию в условиях усиливающихся антропогенных и техногенных нагрузок. Эти решения должны основываться на знании природы тропических лесов, их структуры, особенностей функционирования, способности к самовосстановлению. Однако из-за отсутствия фундаментальных исследований и системы грамотного управления этими лесами негативное воздействие человека на лес почти не снижается эффективность мер по сохранению невысока. В последние годы ученые всего мира и Вьетнама проводили много исследований, связанных с изучением экологии и биоразнообразия тропических лесов, обращая особое внимание на структурные характеристики древостоев и изучение флоры и растительности лесов для того, чтобы найти оптимальные технические решения данной проблемы. Флора заповедника Хау Ка, провинция Ха Жанг, разнообразна по видовому составу и спектру форм жизни. Результаты исследования выявили 520 видов, принадлежащих к 312 родам и 122 семействам 4 ветвей сосудистых растений, Lycopodiophyta, Polypodiophyta, Pinophyta и Magnoliophyta. Из 122 семейств растений, зарегистрированных в районе исследования, они преобладают: Orchidaceae - 6,54, Rubiaceae - 5,19, Lauraceae - 4,62, Rutaceae - 2,69, Moraceae - 2,69, Fabaceae - 2,69 и Vitaceae - 2,31. Исследование растений Хау Ка выявлило 9 групп ассоциаций. Выявлены особенности распределения растительности по основным элементам растительных сообществ по местообитаниям исследуемой территории и структурные элементы на известняковых и почвенных горах. Флора Хау Ка с 5 основными жизненными формами, из которых деревья составляют наиболее многочисленную группу - 42,88. The structural complexity of tropical forests ensures their stability, the ability to develop and survive in the face of increasing anthropogenic and technological pressures. These decisions should be based on knowledge of the nature of tropical forests, their structure, features of functioning, self-healing ability. However, due to the lack of basic research and a competent management system for these forests, the negative impact of man on the forest is almost not reduced The effectiveness of conservation measures is low. In recent years, scientists from all over the world and Vietnam have carried out many studies related to the study of the ecology and biodiversity of tropical forests, paying particular attention to the structuralcharacteristics of stands and the study of the flora and vegetation of forests in order to find optimal technical solutions to this problem. The flora of the Khau Ca Nature Reserve, Ha Giang Province, is diverse in its species composition and spectrum of life forms. The results of the study revealed 520 species belonging to 312 genera and 122 families of 4 branches of vascular plants, Lycopodiophyta, Polypodiophyta, Pinophyta and Magnoliophyta. Of the 122 plant families registered in the study area, they predominate: Orchidaceae - 6.54, Rubiaceae - 5.19, Lauraceae - 4.62, Rutaceae - 2.69, Moraceae - 2.69, Fabaceae - 2.69 and Vitaceae - 2.31. The study also concluded the Khau Ca plants identified 9 association groups. The features of the distribution of vegetation by the main elements of plant communities over the habitats of the studied territory and structural elements on limestone and soil mountains are revealed. Flora Hau Ka with 5 basic life forms of the group, of which the tree group was the highest group with 42.88.

scholarly journals EXTENDING THE LIMITS OF CAMPOS RUPESTRES IN BRAZIL

2021 ◽  
Vol 22 (82) ◽  
pp. 115-137
Author(s):  
Rubens Teixeira De Queiroz ◽  
Bartolomeu Israel De Souza ◽  
José João Lelis Leal Souza ◽  
Joseilsom Ramos De Medeiros ◽  
Christianne Farias Da Fonseca ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Floristic Composition ◽  
Life Forms ◽  
Amazon Rainforest ◽  
Organic Soils ◽  
Campos Rupestres ◽  
Rock Outcrops ◽  
Water Storage Capacity ◽  
Pristine Area ◽  
Caatinga Biome

Campos rupestres are typical ecosystems of rock outcrops with high biodiversity and endemism, located in Brazilian territory, with vegetation analogous in Africa and Australia. The campos rupestres cover deeply dystrophic soils on highlands inserted in Amazon rainforest, Atlantic rainforest and Cerrado biomes. Despite recognition of campos rupestres as a global biodiversity hotspot, little is known its occurrence in dry forests. So, this work aimed to describe vegetable cover and soil properties in highlands associated to rock outcrops on Caatinga biome. A pristine area in Borborema plateau was chosen as study area. Frequency of species and life forms indicate high vegetable density and herbaceous habits predominance. Although the high similarity of species with Caatinga biome, presence of Albizia, Dalbergia, Poecilanthe e Platymiscium indicates a truly distinct floristic composition. Soils are shallower, less fertile and has lower water storage capacity than predominant soils in Caatinga. This work reveals the presence of campos rupestres beyond the areas previously considered favorable to its presence, extending its occurrence to regions of lower precipitation. The occurrence of the campos rupestres is attributed to an additional supply of water from fog in consonance with organic soils. Therefore, areas with similar characteristics should be prioritized to be preserved.

Functional traits, land-use change and the structure of present and future bird communities in tropical forests

2014 ◽  
Vol 23 (10) ◽  
pp. 1073-1084 ◽  
Author(s):  
Tim Newbold ◽  
Jörn P. W. Scharlemann ◽  
Stuart H. M. Butchart ◽  
Çağan H. Şekercioğlu ◽  
Lucas Joppa ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Tropical Forests ◽  
Functional Traits ◽  
Bird Communities

scholarly journals SOIL SEED BANK IN SEASONAL SEMIDECIDUOUS FOREST AND ABANDONED PASTURE

2016 ◽  
Vol 40 (6) ◽  
pp. 991-1001 ◽  
Author(s):  
Sustanis Horn Kunz ◽  
Sebastião Venâncio Martins
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Life Forms ◽  
Successional Stage ◽  
Semideciduous Forest ◽  
Regeneration Stage ◽  
Significant Difference ◽  
Successional Stages ◽  
Pasture Area ◽  
Seasonal Semideciduous Forest

ABSTRACT The objective of this study was to characterize the seed bank in the soil of different successional stages of Seasonal Semideciduous Forest and abandoned pasture in order to understand the natural regeneration potential of these areas. At each successional stage, 30 samples of soil were collected in the rainy and dry seasons to evaluate the qualitative heterogeneity of the forest, at the regeneration stage (FEA) forest, intermediate regeneration stage forest (ISF) and pasture (PAS). The species were classified according to the life form, successional group and dispersion syndrome. The number of individuals germinated was significantly higher (p < 0.001) in the ISF and in the rainy season (15,949 individuals). Richness was higher in the pasture area (79 species), with a significant difference only between the environments. Most species are herbaceous (49.5%), pioneers (76.5%) and zoocory was the main dispersion syndrome (49% of species). The results show that seed bank in the fragment of the regeneration advanced stage forest presents the highest resilience potential, since it is formed by different life forms and, mainly, by early and late secondary species.

scholarly journals Tropical Dry Forest Resilience to Fire Depends on Fire Frequency and Climate

2021 ◽  
Vol 4 ◽  
Author(s):  
Maximilian Hartung ◽  
Geovana Carreño-Rocabado ◽  
Marielos Peña-Claros ◽  
Masha T. van der Sande
Keyword(s):  
Tropical Forests ◽  
Tropical Dry Forest ◽  
Remote Sensing Data ◽  
Fire Frequency ◽  
Dry Forest ◽  
Fire Disturbance ◽  
Fire Intensity ◽  
Forest Resilience ◽  
Landsat Satellite ◽  
In Fire

Wildfires are becoming increasingly frequent and devastating in many tropical forests. Although seasonally dry tropical forests (SDTF) are among the most fire-threatened ecosystems, their long-term response to frequent wildfires remains largely unknown. This study is among the first to investigate the resilience in response to fire of the Chiquitano SDTF in Bolivia, a large ecoregion that has seen an unprecedented increase in fire intensity and frequency in recent years. We used remote sensing data to assess at a large regional and temporal scale (two decades) how fire frequency and environmental factors determine the resilience of the vegetation to fire disturbance. Resilience was measured as the resistance to fire damage and post-fire recovery. Both parameters were monitored for forested areas that burned once (F1), twice (F2), and three times (F3) between 2000 and 2010 and compared to unburned forests. Resistance and recovery were analyzed using time series of the Normalized Burn Ratio (NBR) index derived from Landsat satellite imagery, and climatic, topographic, and a human development-related variable used to evaluate their influence on resilience. The overall resilience was lowest in forests that burned twice and was higher in forests that burned three times, indicating a possible transition state in fire resilience, probably because forests become increasingly adapted during recurrent fires. Climatic variables, particularly rainfall, were most influential in determining resilience. Our results indicate that the Chiquitano dry forest is relatively resilient to recurring fires, has the capacity to recover and adapt, and that climatic differences are the main determinants of the spatial variation observed in resilience. Nevertheless, further research is needed to understand the effect of the higher frequency and intensity of fires expected in the future due to climate change and land use change, which may pose a greater threat to forest resilience.

scholarly journals ENVIRONMENTAL CHANGE AND LANDUSE SCENARIOS UNDER CHANGING CLIMATES: THE EXPERIENCE IN THE UPPER CROSS RIVER REGION, NIGERIA

2020 ◽  
Vol 6 (11) ◽  
pp. 32-42
Author(s):  
Innocent A. Ugbong ◽  
Ivan V. Budagov
Keyword(s):  
Environmental Changes ◽  
Floristic Composition ◽  
Life Forms ◽  
Soil Conditions ◽  
Land Use Patterns ◽  
Cross River ◽  
Cross River State ◽  
Use Patterns ◽  
River Region ◽  
Descriptive Approach

This paper seeks to show that due to changing climates, there are salient marginal Sahelian conditions (conditions of aridity) emerging on the Northern fringes of Cross River State, a state that is geographical positioned in the southern rainforest belt of Nigeria. The paper adopts a simple descriptive approach and shows the distinct characteristics of this zone, in terms of floristic composition and edaphic and geomorphic structures under changing conditions. Some relationships are established between environmental variables like health, water supply and crop-yield on one hand, and climatic variation, floral life-forms and soil conditions on the other. The changing land use patterns relative to environmental changes are also examined. The paper concludes with a look at current and future adaption strategies to these climate-induced conditions.

scholarly journals Characterization and ecological significance of a seed bank from the Upper Pennsylvanian Wise Formation, southwest Virginia

2017 ◽  
Vol 57 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Petra S. Yehnjong ◽  
Michael S. Zavada ◽  
Chris Liu
Keyword(s):  
Seed Size ◽  
Seed Bank ◽  
Seedling Establishment ◽  
Environmental Variability ◽  
Seed Banks ◽  
Evolutionary Strategy ◽  
Predator Population ◽  
Seed Density ◽  
Soil Seed Banks ◽  
Large Seed

AbstractSoil seed banks are important to the maintenance and restoration of floras. Extant seed banks exhibit unique characteristics with regard to the distribution of seed size and seed density. Seeds were recovered from the Upper Pennsylvanian Wise Formation in southwest Virginia. Structurally preserved seeds were also examined from coal balls of the Pennsylvanian Pottsville and Allegheny Groups, Ohio. The size distribution of the seeds from the Wise Formation is similar to that of structurally preserved seeds of the Upper Pennsylvanian Pottsville and Allegheny Group coal balls. In contrast, the seed size distributions in extant wetland, grassland, woodland and forest habitats are significantly narrower than that of seeds from the Pennsylvanian seed banks. Larger seeds are less dependent on light for germination, and aid in seedling establishment more than smaller seeds, especially in dense stable forests where disturbance events are rare. Large seed size may contribute to increased seed longevity, which reduces the effect of environmental variability on seed germination and development. The significantly larger size of the Palaeozoic seeds may have imparted an advantage for seedling establishment in the dense Palaeozoic forests. The preponderance of large seeds may be a result of the absence of large seed predators (e.g. herbivorous tetrapods), and may have been an evolutionary strategy to minimize damage to the embryo from a predator population dominated by small invertebrates with chewing or sucking mouthparts. The estimated seed density of 192 seeds/m2in the Palaeozoic seed bank falls within the range of modern seed banks, but at the lower end of modern seed bank densities in a variety of habitats.

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