OBSERVATIONS ON THE VEGETATION OF MATO GROSSO, BRAZIL. V. CHANGES IN THE WOODY SPECIES DIVERSITY OF A FOREST IN THE CERRADO–AMAZONIAN FOREST TRANSITION ZONE AND NOTES ON THE FORESTS OF THE REGION

2012 ◽  
Vol 69 (2) ◽  
pp. 239-253 ◽  
Author(s):  
H. A. Mews ◽  
B. S. Marimon ◽  
J. A. Ratter

The changes in floristic composition, richness, species diversity and ecological groups of a semideciduous seasonal forest located at 14°49′32″S 52°06′20″W in the Cerrado–Amazonian Forest transition, in the area of Nova Xavantina, eastern Mato Grosso, Brazil, were determined between 2003 and 2008. Sixty permanent plots of 10 × 10 m were established, where the individuals with diameter at breast height (dbh) ≥ 5 cm were recorded and identified. The changes in floristic composition over the period were small and species losses and gains were limited to those of low abundance. The species richness and diversity did not change during this period and observations over a longer period will be necessary to determine whether it is a static community or in a succession towards the relatively nearby Amazonian forests. A review of existing works on the transition forest of Mato Grosso is also given.

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Chirle Colpini ◽  
Versides Sebastião de Moraes e Silva ◽  
Thelma Shirlen Soares ◽  
José Vespasiano Lisboa Assumpção ◽  
Roberto Chiaranda

O objetivo deste estudo foi avaliar as mudanças ocorridas na riqueza e diversidade de espécies em uma floresta ecotonal na região norte mato-grossense. Os dados foram coletados em três ocasiões (2001, antes da exploração, e em 2003 e 2007, após a exploração), em 74 parcelas de 0,25 ha, sendo 69 para estudar a floresta não explorada e 5 para a explorada, com a retirada dos fustes de árvores com diâmetros comercialmente aceitos no mercado. Todos os indivíduos com diâmetro a 1,3 m de altura do solo (Dap) ≥ 17 cm foram mensurados e identificados. A diversidade florística foi avaliada por meio do quociente de mistura de Jentsch e pelo índice de Shannon-Wiener e a equabilidade pelo índice de Pielou. A variação da riqueza e diversidade de espécies antes e após a exploração madeireira foi pequena, o que confirma o baixo impacto da exploração na composição e diversidade das espécies da floresta.Palavras-chave: Diversidade; equabilidade; Amazônia Meridional. AbstractLogging effects on floristic richness and species diversity in an ecotonal forest in northern region of Mato Grosso state, Brazil. The aim of this research was to evaluate changes in relation to floristic richness and species diversity in an ecotonal forest in northern region of Mato Grosso State, Brazil. Data had been collected along three different moments (2001 [before logging], in 2003 and 2007 [after logging]) in 74 0.25-ha plots (69 in unlogged forest and 5 in logged forest). Trees with diameter ≥ 17 cm and 1.3 m height (dbh) had been measured and identified. Floristic diversity was evaluated by Jentsch Coefficient of Mixture and Shannon-Wiener index as well as its equability by Pielou’s Index. There were little variations before and after logging in relation to floristic richness and species diversity, it confirms low impact of exploration on floristic composition and species diversity of the forest.Keywords: Diversity; equability; Southern Amazonia. 


2006 ◽  
Vol 63 (2-3) ◽  
pp. 323-341 ◽  
Author(s):  
B. S. MARIMON ◽  
E. DE S. LIMA ◽  
T. G. DUARTE ◽  
L. C. CHIEREGATTO ◽  
J. A. RATTER

A study was made of the transition between the cerrado and Amazonian forest biomes on the Serra do Roncador in the northeast of Mato Grosso State, Brazil. The transition was sampled by recording the species and circumference at breast height (cbh) of all woody species ≥ 15 cm cbh on five 20 × 10 m plots in each of the following four communities: ecotonal vegetation (Cerradão areas 1 and 2), and forest (Forest areas 1 and 2); while in the Cerrado sensu stricto a more rapid method had to be used because of time constraints. A total of 138 species was recorded and the results were analysed using Sørensen and Morisita Indices, TWINSPAN and DCA. In addition, comparisons were made with data from studies undertaken in 1968 in the same area by the Xavantina-Cachimbo Expedition. No species was common to all communities sampled but a seral succession of important species occurs along the transition. The Sørensen and Morisita Indices demonstrate this, with the Cerrado s.s. and Forest 2 at the two extremes showing no species in common (zero similarity) and Cerradão 1 and 2 giving the very high figures of Sørensen 0.64 and Morisita 0.84. The ecotonal cerradão is a very characteristic Dystrophic facies cerradão with Hirtella glandulosa, Emmotum nitens, Sclerolobium paniculatum and Vochysia haenkeana as its typical indicator species. The ecotone studied in the present work represents the comparatively abrupt transition from cerrado to the peripheral form of Amazonian forest (dry forest, mata seca) on flat terrain with a uniform very dystrophic soil. Other workers have suggested that this type of transition may be restricted to the headwaters of the Xingu basin, but one of the present authors has seen similar vegetation at localities in Maranhão, Rondônia, and on the Mato Grosso–Rondônia border. Comparison of the present vegetation with the survey made in 1968 shows that in this area the advancing face of the Amazonian forest has extended about 7 km southwards into the cerrado. However, in the majority of places this process has been obscured by forest clearing for agriculture. The study draws attention to the urgent need for the establishment of conservation areas in this extremely threatened and very little studied ecotone.


FLORESTA ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 154
Author(s):  
Thyêgo Nunes Alves Barreto ◽  
Rinaldo Luiz Caraciolo Ferreira ◽  
José Antônio Aleixo Silva ◽  
Cleuma Christir da silva Almeida ◽  
Andréa de Vasconcelos Freitas Pinto

Studying selected floristic changes in dry forests is fundamental to foster conservation and sustainability strategies. Objective: to analyze the occurrence of woody species in a tropical forest with a history of use. In 2008, 40 permanent plots were installed and wood with a circumference of 1.30 m at a breast height (CAP) ≥ 6 cm were measured. In 2012, newly established individuals (those that did not meet the size requirements in 2008 but did in 2012) and mortality of the remaining individuals were analyzed by computer. Where applicable, the density, frequency, and absolute dominance, importance value, newly established individuals, mortality, and gross growth for each species, along with the Shannon index were estimated. The floristic composition and diversity remain unchanged. After four years, there were few differences between species, while in most cases the growth in the basal area was positive and sometimes the number of newly established individuals exceeded the mortality. After 24 years of logging, the analyzed forest area did not reach its initial basal area stock when compared to other areas of the Caatinga that do not have a history of disturbance.


2019 ◽  
Vol 29 (3) ◽  
pp. 1082
Author(s):  
Marcos José Gomes Pessoa ◽  
Jéssica Jeini Guisoni ◽  
Priscila Fernanda Simioni ◽  
Saulo Pireda ◽  
Vanessa Xavier ◽  
...  

Qualea é um gênero comumente encontrado em diferentes fisionomias do cerrado brasileiro, crescendo em ecossistemas abertos até áreas florestais fechadas, sujeitos à alta irradiância, incêndios, baixa disponibilidade de nutrientes e deficit hídrico sazonal. Comparam-se aqui, atributos estruturais foliares de Qualea grandiflora Mart., Qualea multiflora Mart., e Qualea parviflora Mart., em uma área de cerradão na transição entre os biomas Cerrado-Amazônia. Amostras foliares foram coletadas na Reserva Biológica Municipal Mário Viana, Nova Xavantina, Mato Grosso – Brasil, e processadas segundo as técnicas usuais para microscopia óptica. Cutícula espessa, cristas estomáticas, estômatos distribuídos entre as criptas estomáticas, densidade e distribuição dos tricomas tectores, hipoderme, mesofilo isobilateral com poucos espaços intercelulares, abundância de esclerênquima associado aos feixes vasculares e presença de extensões de bainha do feixe vascular são atributos anatômicos típicos de ambientes xerófilos. Encontraram-se diferenças estruturais qualitativas entre as espécies, com Qualea grandiflora apresentando estômatos com cristas distribuídos entre criptas estomáticas, e a presença de hipoderme em Qualea multiflora, e Qualea parviflora.  Os resultados sugerem que as espécies são xeromórficas na região de transição Cerrado-Amazônia e que possuem atributos foliares adaptativos para lidar com as variações ambientais do seu habitat.


2015 ◽  
Vol 73 (1) ◽  
pp. 83-93 ◽  
Author(s):  
P. S. Morandi ◽  
B. H. Marimon-Junior ◽  
E. A. de Oliveira ◽  
S. M. Reis ◽  
M. B. Xavier Valadão ◽  
...  

The occurrence of cerrado (as tree and shrub savanna is called in Brazil) and forest formations side by side is common at the southern margin of the Brazilian Amazonian Forest, and previous studies have demonstrated the advance of forests over cerrado areas. The aim of the present study is to provide an accurate documentation of the transition process between the two major biomes. Tree data (≥ 5 cm diameter at 0.3 m above soil level) from three plots of cerrado sensu stricto lying near three of cerradão (the taller, denser form of cerrado) were inventoried starting in 2002 in an area of 1.5 ha made up of 150 subplots of 10 × 10 m (50 in each area). This showed that the most important species of the cerradão were invading areas previously occupied by smaller, lower forms of cerrado (although it is sometimes difficult to define which are ‘forest’ and which ‘cerrado’ species as many are flexible in size – for instance Emmotum nitens can often be intermediate, establishing in cerrado that develops into cerradão and on to forest). Some typical species such as Eriotheca gracilipes and Emmotum nitens, established since the first inventories, have increased their populations (between 27 and 210%). Tachigali vulgaris, a typical, weedy, adventive species of the Cerrado–Amazonian Forest transition, showed the largest increase in abundance in areas of cerrado sensu stricto (between 100 and 1200%), and is probably the most important pioneer species in the initial advance of the forest into cerrado at the Southern Amazonian border.


2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Ezekiel Edward Mwakalukwa ◽  
Henrik Meilby ◽  
Thorsten Treue

For the majority of forest reserves in Tanzania, biodiversity is poorly documented. This study was conducted to assess species richness (woody species), diversity, and forest structure and to examine relationships between species occurrence and topographic and edaphic factors in the Gangalamtumba Village Land Forest Reserve, a dry Miombo woodland area in Tanzania. A total of 35 nested circular plots with radii of 5, 15, and 20 m were used to collect data on woody species and soil samples across the 6,065 ha community-managed forest reserve. Stumps were measured 20 cm above ground. A total of 88 species belonging to 29 families were identified. Generally forest structure parameters and diversity indices indicated the forest to be in a good condition and have high species richness and diversity. Vegetation analysis revealed four communities of which two were dominated by the family Caesalpiniaceae, indicating large variation of site conditions and possible disturbances in the study area. The high level of diversity of woody species and the high basal area and volume indicate that the forest is in good condition, but the effect of anthropogenic activities is evident and stresses the need for proper management to maintain or enhance the present species diversity.


2014 ◽  
Author(s):  
S. M. Feroz ◽  
Rempei Suwa ◽  
Koh Nakamura ◽  
Akio Hagihara ◽  
Masatsugu Yokota

ABSTRACTIn order to compare stand structure and woody species diversity of subtropical evergreen broadleaf forests along a latitudinal thermal gradient of the Ryukyu Archipelago, tree censuses in a 750 m2 plot in Okinawa Island and a 400 m2 plot in Ishigaki Island were performed. The number of layers increased along a latitudinal thermal gradient from four in the forest of Okinawa Island to five in the forest of Ishigaki Island. The values of Shannon’s index H′ and Pielou’s index J′ tended to increase from the top layer downward in the forest of Okinawa Island, whereas in the forest of Ishigaki Island, these values tended to increase from the bottom layer upward. High woody species diversity depended on small-sized trees in the Okinawa forest, whereas it depended on large-sized trees in the Ishigaki forest. The woody species diversity is higher in the Okinawa forest (H′ = 4.83 bit) than in the Ishigaki forest (H′ = 4.36 bit). According to successively decreasing height of layers from the top downward, the value of H′ increased continuously from the top layer downward in the Okinawa forest. This increasing trend was different from the Ishigaki forest, where the value of H′ increased up to the second layer and then decreased downward. In the Okinawa forest, the expected number of species increased continuously from the top toward the bottom layer, i.e. the bottom layer contained the highest potential number of species (65). However, in the Ishigaki forest, it increased from the top to the fourth layer and then decreased to the bottom layer, i.e. the fourth layer contained the highest potential number of species (90). The floristic composition in the Okinawa forest was different from that in the Ishigaki forest in terms of similarity index, though approximately half of the species were common between them. The highest degree of similarity in floristic composition was between the second and third layers in the Okinawa forest, whereas it was between the third and bottom layers in the Ishigaki forest. The degree of similarity in floristic composition among layers was higher in the Okinawa forest than in the Ishigaki forest. Except the top and the bottom layer respectively in the forests of Okinawa Island and Ishigaki Island, the spatial distribution of trees was random in each layer. The degree of overlapping in the spatial distribution of trees among layers in these two forests suggested that trees in the upper two layers in the Ishigaki forest can catch sufficient light, while light can not penetrate easily to the lower three layers in both of the forests. As a result, almost species in the lower layers might be shade-tolerant in both of the forests. For both of the forests, mean tree weight of each layer decreased from the top downward, whereas the corresponding tree density increased from the top downward. This trend resembled the mean weight–density trajectory of self-thinning plant populations.


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