scholarly journals Effects of prescribed fires on the survival and release of seeds of Kielmeyera coriacea (Spr.) Mart. (Clusiaceae) in savannas of Central Brazil

2008 ◽  
Vol 20 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Paulo Cirne ◽  
Heloisa Sinátora Miranda
Keyword(s):  
Prescribed Fire ◽  
Germination Rate ◽  
Woody Species ◽  
Sensu Stricto ◽  
Dry Season ◽  
Prescribed Fires ◽  
Seed Survival ◽  
Central Brazil ◽  
Savanna Vegetation ◽  
Kielmeyera Coriacea

Effects of prescribed fires on survival and release of seeds of the woody species Kielmeyera coriacea (Clusiaceae) were investigated in two plots of cerrado sensu stricto, a savanna vegetation of Central Brazil. The first plot was burnt in June, at the beginning of the dry season, and the second in August, in the middle of the dry season. Seed survival was measured after fire in both areas and related to internal and external fruit temperatures measured during the June fire. The proportion of open fruits per individual of K. coriacea was also assessed at two-week intervals. Maximum external temperatures during fire (393 to 734ºC) were strongly reduced inside the fruits (61 to 63ºC). Before the June fire, the majority of the fruits were closed in both plots. Most fruits in the June plot opened within two weeks following the burning while, in the same period, most fruits remained closed in the August plot. Fifteen days after the prescribed fire in the August plot most fruits opened, as observed in the June plot. No germination was observed in seeds from closed fruits collected before the fire, while those from fruits that were closed during the burning showed a high mean germination rate (June = 79 ± 12%; August = 69 ± 14%). The results indicate that fruits of K. coriacea are good insulators for seeds during fires and that seed release is anticipated independently of the burning season.

scholarly journals The length of the dry season may be associated with leaf scleromorphism in cerrado plants

2015 ◽  
Vol 87 (3) ◽  
pp. 1691-1699 ◽  
Author(s):  
MARCELO C. SOUZA ◽  
AUGUSTO C. FRANCO ◽  
MUNDAYATAN HARIDASAN ◽  
DAVI R. ROSSATTO ◽  
JANAÍNA F. DE ARAÚJO ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Specific Leaf Area ◽  
Woody Species ◽  
Dry Season ◽  
Core Region ◽  
The Other ◽  
Low Fertility ◽  
Fertility Rates ◽  
Cerrado Vegetation ◽  
Central Brazil

Despite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP). We contrasted the length of the dry season, soil fertility rates, leaf concentrations of N, P, K, Ca and Mg and the specific leaf area (SLA) between these communities. The dry season was shorter on the periphery, where the soil was more fertile although more acidic. Plants from the periphery showed higher SLA and higher leaf concentrations of N, P, Ca and Mg. We propose that the higher SLA of plants from the periphery is related to the shorter dry season, which allows better conditions for nutrient uptake.

A phytogeographic analysis of the woody elements of New World savannas

1999 ◽  
Vol 56 (2) ◽  
pp. 293-305 ◽  
Author(s):  
J. C. Lenthall ◽  
S. Bridgewater ◽  
P. A. Furley
Keyword(s):  
New World ◽  
Floristic Composition ◽  
Woody Species ◽  
Multivariate Techniques ◽  
Southern Mexico ◽  
Central Brazil ◽  
Savanna Vegetation ◽  
Great Heterogeneity ◽  
Southern Amazonia ◽  
Floristic Variation

An analysis was made of the floristic composition of 45 savanna sites located throughout the southern neoarctic and neotropics. A total of 533 woody species were recorded from published and reliable unpublished floristic lists; of these, 234 species (44%) were from 10 Brazilian cerrado sites, with 187 (80%) of them restricted to the cerrado biome. The cerrados were clearly shown to be the most diverse New World savanna system with a high degree of endemism. The data were analysed using two multivariate techniques: TWINSPAN and DCA. Four phytogeographic zones were identified: Central Brazil and Bolivia extending to Southern Amazonia; north of Amazonia extending across the isthmus of Central America and including the Caribbean; Belize, Guatemala and Southern Mexico; and north of the Mexican Plateau. The analyses revealed gradients of floristic variation associated with latitude and longitude, and showed the great heterogeneity of savanna vegetation.

EFEITO DO DESMATAMENTO NO ESTABELECIMENTO DE ESPÉCIES LENHOSAS EM UM CERRADO Sensu stricto

FLORESTA ◽  
2005 ◽  
Vol 35 (1) ◽  
Author(s):  
Alba Valéria Rezende ◽  
Carlos Roberto Sanquetta ◽  
Afonso Figueiredo Filho
Keyword(s):  
Woody Species ◽  
Sensu Stricto ◽  
Woody Vegetation ◽  
Floristic Richness ◽  
Different Types ◽  
Species Establishment ◽  
Caryocar Brasiliense ◽  
Kielmeyera Coriacea

Avaliou-se o efeito de diferentes tipos de corte raso no estabelecimento da vegetação lenhosa arbóreaarbustiva de um cerrado sensu stricto, localizado em Brasília, DF. Em 1988 foi implantado na área de estudo um experimento contendo dezoito parcelas de 20x50m submetidas a seis tratamentos envolvendo diferentes combinações de corte. Antes da implantação dos tratamentos foram registrados em cada parcela os indivíduos lenhosos com Db ≥ 5cm. Em 2000 foi realizado o levantamento dos indivíduos (Db ≥ 5cm) estabelecidos em todas as parcelas. Verificou-se que os impactos dos tratamentos variaram de acordo com a intensidade. Riqueza florística, similaridade, diversidade e estrutura atingiram valores próximos aos encontrados na flora original. Espécies pouco representativas do cerrado estudado destacaram-se nas áreas que sofreram os distúrbios, entretanto, foram também registradas altas densidades de espécies importantes da flora original: Caryocar brasiliense, Kielmeyera coriacea, Ouratea hexasperma e Qualea grandiflora. Os resultados sugerem que a comunidade apresenta alto grau de resiliência. Effect of the clearcutting on woody species establishment in a cerrado sensu stricto Abstract The effect of the clearcutting on the floristic and structure was assessed in cerrado sensu stricto woody vegetation, in Brasília, DF, Brazil. In 1988, eighteen plots of 20x50m of the cerrado were subjected to six treatments with different types of clearcutting. Prior to the treatments, all individuals with Db ≥ 5cm were registered. A new assessment of all woody individuals with Db ≥ 5cm that colonized all areas was conducted in 2000. The impacts of the treatments varied according to their intensity but in eleven years, the floristic richness, similarity, diversity and structure reached values near to the values of the original flora. The various treatments favoured the establishment of several species with small densities in the original flora and other abundant too such as Caryocar brasiliense, Kielmeyera coriacea, Ouratea hexasperma and Qualea grandiflora. The results suggested a highly resilient community.

scholarly journals Impacts of increasing fine fuel loads on acorn germination and early growth of oak seedlings

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Rachel E. Nation ◽  
Heather D. Alexander ◽  
Geoff Denny ◽  
Jennifer K. McDaniel ◽  
Alison K. Paulson
Keyword(s):  
Prescribed Fire ◽  
Germination Rate ◽  
Growth Patterns ◽  
Leaf Number ◽  
Fuel Load ◽  
Quercus Alba ◽  
White Oak ◽  
Fuel Treatment ◽  
Basal Diameter ◽  
Fuel Loads

Abstract Background Prescribed fire is increasingly used to restore and maintain upland oak (Quercus L. spp.) ecosystems in the central and eastern US. However, little is known about how prescribed fire affects recently fallen acorns under different fine fuel loads, which can vary with stand composition and basal area, burn season, and fire frequency. We conducted plot-level (1 m2) burns in an upland oak stand in northern Mississippi, USA, during December 2018, using single (i.e., ambient), double, and triple fine fuel loads, representative of those in nearby unburned and recently fire-treated, closed-canopy stands. Pre burn, we placed 30 acorns each of white oak (Quercus alba L.) and Shumard oak (Quercus shumardii Buckley) ~1 cm below the litter surface in five plots of each fuel treatment. Immediately post burn, we planted unburned and burned acorns in a greenhouse. After ~50% of each species’ unburned acorns germinated, we measured percent germination and height, basal diameter, and leaf number of germinating seedlings weekly for 11 weeks. Then, we harvested seedlings to determine above- and belowground biomass. Results The single fuel treatment reduced acorn germination rates of both species to ~40% compared to ~88% in unburned acorns. When burned in double and triple fuel loads, acorns of both species had a <5% germination rate. There was no difference in basal diameter, leaf number, or biomass of seedlings from burned versus unburned acorns for either species. However, seedlings originating from burned acorns of both species were ~11% shorter than those from unburned acorns. Thus, both species responded similarly to fuel load treatments. Conclusions Acorns of both species exhibited greater survival with lower fine fuel loads, and consequently lower percent fuel consumption. Acorns germinating post fire generally produced seedlings with growth patterns similar to seedlings originating from unburned acorns. These findings indicate that regular, repeated prescribed fires or canopy reductions that limit fine fuel accumulation and create heterogeneous fuel beds are likely to increase acorn germination rates relative to unburned sites or those with recently introduced fire.

scholarly journals Somatic embryo induction and Agrobacterium-mediated transformation of embryonic callus tissue in Phoebe bournei, an endangered woody species in Lauraceae

2020 ◽  
Vol 48 (2) ◽  
pp. 572-587
Author(s):  
Wenting XU ◽  
Miao ZHANG ◽  
Chen WANG ◽  
Xiongzhen LOU ◽  
Xiao HAN ◽  
...  
Keyword(s):  
Genetic Transformation ◽  
Germination Rate ◽  
Molecular Genetic ◽  
Genetic Research ◽  
Woody Species ◽  
Technical System ◽  
Transformation Rate ◽  
Original Material ◽  
Embryonic Callus ◽  
Phoebe Bournei

Phoebe bournei, a plant species endemic to China, is a precious timber tree and widely used in landscaping. This tree contains numerous secondary metabolites, underscoring its potential economic value. However, studies on this species, including molecular genetic research, remain limited. In this study, both a somatic embryogenesis (SE) technical system and Agrobacterium-mediated genetic transformation were successfully employed in P. bournei for the first time. The SE technical system was constructed using immature embryos as original material. The primary embryo and embryonic callus induction rates were 30.66% and 41.67%, respectively. The highest rate of embryonic callus proliferation was 3.84. The maximum maturity coefficient and germination rate were 53.44/g and 39%, respectively. Agrobacterium-mediated genetic transformation was performed using the SE technical system, and the highest transformation rate was 11.24%. The results presented here are the first to demonstrate an efficient approach to achieve numerous P. bournei plantlets, which serves as the basis for artificial cultivation and resource conservation. Furthermore, the genetic transformation platform constructed in this study will facilitate assessment of gene function and molecular regulation.

Prescribed Fire and the Response of Woody Species in Willamette Valley Wetland Prairies

1998 ◽  
Vol 6 (3) ◽  
pp. 303-311 ◽  
Author(s):  
K. L. Pendergrass ◽  
P. M. Miller ◽  
J. B. Kauffman
Keyword(s):  
Prescribed Fire ◽  
Woody Species ◽  
Willamette Valley

Use of deciduous woody species as a diet supplement for goats grazing Mediterranean shrublands during the dry season

1999 ◽  
Vol 80 (3-4) ◽  
pp. 267-279 ◽  
Author(s):  
T.G Papachristou ◽  
P.D Platis ◽  
V.P Papanastasis ◽  
C.N Tsiouvaras
Keyword(s):  
Woody Species ◽  
Dry Season ◽  
Mediterranean Shrublands ◽  
Diet Supplement

scholarly journals The influence of prescribed fire on the extent of wildfire in savanna landscapes of western Arnhem Land, Australia

2012 ◽  
Vol 21 (3) ◽  
pp. 297 ◽  
Author(s):  
Owen F. Price ◽  
Jeremy Russell-Smith ◽  
Felicity Watt
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Prescribed Fire ◽  
Fire History ◽  
Prescribed Burning ◽  
Landsat Imagery ◽  
Fire Regimes ◽  
Dry Season ◽  
Gas Emissions ◽  
Arnhem Land

Fire regimes in many north Australian savanna regions are today characterised by frequent wildfires occurring in the latter part of the 7-month dry season. A fire management program instigated from 2005 over 24 000 km2 of biodiversity-rich Western Arnhem Land aims to reduce the area and severity of late dry-season fires, and associated greenhouse gas emissions, through targeted early dry-season prescribed burning. This study used fire history mapping derived mostly from Landsat imagery over the period 1990–2009 and statistical modelling to quantify the mitigation of late dry-season wildfire through prescribed burning. From 2005, there has been a reduction in mean annual total proportion burnt (from 38 to 30%), and particularly of late dry-season fires (from 29 to 12.5%). The slope of the relationship between the proportion of early-season prescribed fire and subsequent late dry-season wildfire was ~–1. This means that imposing prescribed early dry-season burning can substantially reduce late dry-season fire area, by direct one-to-one replacement. There is some evidence that the spatially strategic program has achieved even better mitigation than this. The observed reduction in late dry-season fire without concomitant increase in overall area burnt has important ecological and greenhouse gas emissions implications. This efficient mitigation of wildfire contrasts markedly with observations reported from temperate fire-prone forested systems.

Longleaf Pine (Pinus palustris Mill.) Branch Pruning by Prescribed Fire

2021 ◽  
Author(s):  
John P McGuire ◽  
John S Kush ◽  
J Morgan Varner ◽  
Dwight K Lauer ◽  
J Ryan Mitchell
Keyword(s):  
Prescribed Fire ◽  
Longleaf Pine ◽  
Wood Quality ◽  
Pinus Palustris ◽  
Planting Density ◽  
Prescribed Fires ◽  
Pine Tree ◽  
Southeastern Us ◽  
Tree Survival ◽  
The Impact

Abstract Efforts to restore longleaf pine (Pinus palustris Mill.) in the southeastern US require substantial artificial regeneration. Once established, important questions remain about when to introduce fire. We investigated the impact of initial planting density on tree branching and how prescribed fire might interact with tree architecture and survival. A particular focus was on how prescribed fires could “prune” lower branches. Lower density plantings (897 trees ha−1) had more and larger live lower branches than higher density plantings (2,243 trees ha−1). Fire was effective in pruning lower branches regardless of season burned, but fire in the growing season was more effective at pruning. Branches up to a height of 1.5 to 2 m were killed by fire. Fire applied in August caused greater damage with more needles scorched and/or consumed and more stem char. Prescribed fire did not impact longleaf pine tree survival. In general, fire applied to longleaf pine facilitated pruning lower branches that affect long-term wood quality, an additional argument for its utility in restoration and management of these ecosystems.

scholarly journals Comparative study of the zooplankton composition of six lacustrine ecosystems in Central Brazil during the dry season

2000 ◽  
Vol 60 (1) ◽  
pp. 101-111 ◽  
Author(s):  
F. L. do R. M. STARLING
Keyword(s):  
Zooplankton Community ◽  
Federal District ◽  
Dry Season ◽  
Zooplankton Species ◽  
Waste Stabilisation Ponds ◽  
Central Brazil ◽  
Morphometric Features ◽  
Santa Maria ◽  
Sørensen Index

Zooplankton community from six lacustrine ecosystems located in Federal District (Central Brazil) was studied based on samples collected during the dry season (July to September). A total of 71 taxa were recorded: 44 rotifers, 17 cladocerans and 10 copepods. The highest number of zooplankton species was recorded in oligotrophic Bonita Pond (32 species) and the lowest number in hypertrophic waste stabilisation ponds (7 species). This tendency of decreasing the diversity with increasing trophic level was consistent with a cluster analysis of the samples based on Sorensen index of similarity. From the overall similarity dendrogram, two groups of ecosystems were distinguished: one containing the natural ponds Bonita and Formosa and the other comprising the reservoirs Santa Maria, Descoberto and Paranoá. The role of morphometric features in determining the zooplankton community in such lacustrine ecosystems was also discussed.

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