scholarly journals Woody species distribution across a savanna-dry forest soil gradient in the Brazilian Cerrado

2023 ◽  
Vol 83 ◽  
Author(s):  
G. A. Paula ◽  
E. Fischer ◽  
M. Silveira ◽  
H. Almeida ◽  
E. van den Berg

Abstract Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Anna P. Rodrigues ◽  
Elena Moltchanova ◽  
David A. Norton ◽  
Matthew Turnbull

AbstractBiotic factors such as the presence of invasive animal and/or plant species are well known as major causes of ecological degradation and as limiting either natural or assisted (human-induced) ecological restoration. However, abiotic aspects of the landscape, such as water availability and soil physical/chemical conditions can also potentially limit restoration and should be considered. Dryland ecosystems are amongst the world’s most threatened and least protected. New Zealand’s drylands have been drastically changed, initially through burning, agricultural and grazing practices and the impacts of introduced herbivores and plants. This research aimed at identifying some of the key environmental factors preventing the reestablishment of native woody species in a New Zealand dryland ecosystem. The experiments involved a combination of shading, irrigation and grazing exclusion. The results showed that supplemental water was not beneficial for the survival and growth of the native seedlings, unless combined with shade. Fencing proved important for establishment, even though the species used are regarded in the literature as unpalatable to herbivores. The results indicated that the presence of shade was fundamental for the establishment and growth of the native seedlings likely due to improvements in the microclimate, soil aeration, and water availability to seedlings.


Check List ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 1862 ◽  
Author(s):  
Miguel Briones-Salas ◽  
Natalia Martín-Regalado ◽  
Mario C. Lavariega

The tropical dry forests of Mexico are one of the world’s biodiversity hotspots. To contribute to the knowledge of mammal diversity and conservation of the central coast of Oaxaca State, southern Mexico, we conducted field surveys in the area. Additional information was obtained from literature and museum databases. In order to compare the taxonomic similitude between areas along the Planicie Costera del Pacífico province we performed a taxonomic similarity analysis using data from the literature and the present study. A total of 49 species of mammals belonging to 19 families and eight orders were recorded. The maximum number of species was recorded in deciduous forest (n = 46), followed by semideciduous forest (n = 11). The similarity index was low (<50%) between areas along the Planicie costera del Pacífico, indicating higher species turnover. The high mammal diversity, the presence of endemic (8%), threatened species (16%), and voluntary conservation areas highlight the importance of this region.


2009 ◽  
Vol 39 (12) ◽  
pp. 2460-2469 ◽  
Author(s):  
Lisa M. Krueger ◽  
Chris J. Peterson ◽  
Alejandro Royo ◽  
Walter P. Carson

Interspecific differences in shade tolerance among woody species are considered a primary driving force underlying forest succession. However, variation in shade tolerance may be only one of many interspecific differences that cause species turnover. For example, tree species may differ in their sensitivity to herbivory. Nonetheless, existing conceptual models of forest dynamics rarely explicitly consider the impact of herbivores. We examined whether browsing by white-tailed deer ( Odocoileus virginianus Zimmermann) alters the relationship between light availability and plant performance. We monitored growth and survival for seedlings of six woody species over 2 years within six windthrow gaps and the nearby intact forest in the presence and absence of deer. Browsing decreased seedling growth for all species except beech ( Fagus grandifolia Ehrh.). More importantly, browsing altered growth rankings among species. Increased light availability enhanced growth for three species when excluded from deer, but browsing obscured these relationships. Browsing also reduced survival for three species; however, survival rankings did not significantly differ between herbivory treatments. Our results indicated that browsing and light availability operated simultaneously to influence plant growth within these forests. Thus, existing models of forest dynamics may make inaccurate predictions of the timing and composition of species reaching the canopy, unless they can account for how plant performance varies as a result of a variety of environmental factors, including herbivory.


2019 ◽  
Vol 67 (1) ◽  
pp. 70
Author(s):  
P. M. S. Rodrigues ◽  
J. O. Silva ◽  
C. E. G. R. Schaefer

Edaphic gradients can explain plant species distribution at a local scale in the neotropics and elsewhere, but few studies have evaluated the individual responses of species to such gradients. We collected data on species and soils in open savannic and forest formations (totalling five habitats in each formation), aiming to evaluate the importance of edaphic factors on the distribution of woody plant species in tropical habitats. Logistic regression was used to test the influence of predictor variables (soil texture and fertility) on plant occurrence (presence or absence). Most species (73%) responded to the edaphic gradients. However, the edaphic gradients did not explain the distribution of the remaining 27% of species, which implies the existence of other factors determining their occurrence. Soil fertility (nutritional status) was the major factor in forest habitats (65% of the species which showed significant response), while soil texture was the most explanatory factor for species occurrence in open habitats (55% of the species that showed a significant response). Thus, nutrient status was less limiting and soil texture was more limiting in savannic formations, whereas the opposite was observed for forest formations. Most species showing a relationship with edaphic gradients had a unimodal response, which is in accordance with the literature. Our study showed that soil properties largely regulate the distribution of plant species in tropical habitats, despite other factors not investigated here also having an effect on several of the studied species. Models of species distribution that take into account environmental heterogeneity are key for the elaboration of strategies for the conservation and restoration of ecosystems.


2007 ◽  
Vol 546-549 ◽  
pp. 1919-1922
Author(s):  
Fen Li ◽  
Tao Guo ◽  
Kai Cheng Zhang ◽  
Chin Ping Chen ◽  
Qing Rong Feng

The thick MgB2 films have been successfully grown on the Cu substrate by the technique of hybrid physical-chemical vapor deposition (HPCVD). The films are about 2 ~ 3 μm and quite dense. They possess the Tc (onset), as high as 37-38 K, and sharp transition ~ 0.8 K. X-ray diffraction (XRD) indicates their polycrystalline character. The upper critical field at T=0K, HC2(0), is extrapolated as 15.3T. The controlled growth of MgB2 film on Cu substrate opens a new route in the preparation of MgB2 tape materials.


2021 ◽  
Vol 4 ◽  
Author(s):  
Andrea Jara-Guerrero ◽  
Diego González-Sánchez ◽  
Adrián Escudero ◽  
Carlos I. Espinosa

Chronic disturbance is widely recognized as one of main triggers of diversity loss in seasonally dry tropical forests (SDTFs). However, the pathways through which diffuse disturbance is acting on the forest are little understood. This information is especially demanded in the case of vanishing Neotropical seasonally dry forests such as the Tumbesian ones. We proposed a conceptual model to analyze the factors behind the loss of woody species richness along a forest disturbance gradient, explicitly considering the existence of direct and indirect causal pathways of biodiversity loss. We hypothesized that the chronic disturbance can act on the woody species richness directly, either by selective extraction of resources or by browsing of palatable species for livestock, or indirectly, by modifying characteristics of the forest structure and productivity. To test our model, we sampled forest remnants in a very extensive area submitted to long standing chronic pressure. Our forests cells (200 × 200 m) were characterized both in terms of woody species composition, structure, and human pressure. Our structural equation models (SEMs) showed that chronic disturbance is driving a loss of species richness. This was done mainly by indirect effects through the reduction of large trees density. We assume that changes in tree density modify the environmental conditions, thus increasing the stress and finally filtering some specific species. The analysis of both, direct and indirect, allows us to gain a better understanding of the processes behind plant species loss in this SDTF.


2020 ◽  
pp. 1756-1763
Author(s):  
Letícia Alves Carvalho Reis ◽  
Maria do Céu Monteiro Cruz ◽  
Enilson de Barros Silva ◽  
Josimara Mendes Rabelo ◽  
Cintia Maria Teixeira Fialho

With the increasing demand for pitaya orchard management information to achieve high productivity and commercial quality fruits, liming practice is fundamental since most Brazilian soils are acidic. This study aims to assess lime requirements of Typic Quartzipisamment and Haplorthox soils to calculate tolerated aluminum saturation, desired base saturation, calcium and magnesium requirements to cultivate two pitaya species; Hylocereus undatus and Hylocereus polyrhizus. Two independent experiments were conducted in a greenhouse, organized in a 2 x 4 factorial scheme. Treatments were distributed in randomized blocks with five replications. Treatments of the first experiment corresponded to H. undatus and H. polyrhizus and four lime requirements, 0; 0.8; 1.2 and 1.7 t ha-1 cultivated in Typic Quartzipisamment. Treatments of the second experiment corresponded to H. undatus and H. polyrhizus and four lime requirements, 0; 1.3; 2.0 and 2.8 t ha-1 cultivated in Haplorthox. Shoot and root dry matter, chemical soil attributes and shoot nutrient concentrations were measured. Regression equations were adjusted for each variable, according to the lime requirements of both soils providing the highest dry matter yield in both pitaya species. H. undatus and H. polyrhizus cultivated in Typic Quartzipisamment produced more dry matter when the aluminum saturation was between 13% and 16%, base saturation 70% and the calcium and magnesium requirement 2.5 cmolcdm-3. H. undatus and H. polyrhizus cultivated in Haplorthox produced more dry matter when the aluminum saturation was between 1% and 4%, base saturation between 55% and 70%, and calcium and magnesium requirement 3.0 cmolcdm-3.


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.


2021 ◽  
Vol 19 (3) ◽  
pp. 517-524
Author(s):  
Rinto Manurung ◽  
Rossie Wiedya Nusantara ◽  
Ismahan Umran ◽  
W. Warganda

Kebakaran lahan gambut menyebabkan terjadinya perubahan sifat fisika, kimia dan biologi tanah gambut sehingga secara otomatis mempengaruhi kualitas tanah yang dinyatakan dengan Indeks Kualitas Tanah (IKT). Tujuan penelitian ini adalah menentukan indeks kualitas tanah dan faktor penentunya pada lahan gambut terbakar (GT) dan tidak terbakar (GTT). Penelitian dilakukan di Kelurahan Bansir Darat Kecamatan Pontianak Tenggara Kota Pontianak pada GTT  dan GT. Tahapan penelitian meliputi pengambilan sampel tanah pada masing-masing lahan, pengamatan dan pengukuran kedalaman gambut, ketebalan lapisan gambut dan kematangan gambut serta perhitungan jumlah cacing. Analisis sifat fisika tanah meliputi bobot isi, kadar air kapasitas lapang, porositas total; sifat kimia tanah terdiri dari reaksi tanah (pH), karbon organik (C-organik), Nitrogen total (N-total), rasio CN, posfor tersedia (P-tersedia), natrium, kalium, kalsium dan magnesium dapat dipertukarkan (Na-dd, K-dd, Ca-dd dan Mg-dd), kapasitas tukar kation (KTK), kejenuhan basa (KB), kadar abu; dan jumlah cacing tanah untuk sifat biologi tanah. Hasil penelitian menunjukkan GT dengan kematangan saprik memiliki kedalaman gambut lebih dangkal dibandingkan GTT dengan kematangan hemik. Kadar air dan porositas pada GT juga lebih rendah dibandingkan GTT. Kation basa GT lebih tinggi dibandingkan GTT meskipun kriteria keduanya sangat rendah. Parameter penentu kualitas tanah yaitu C-organik, CN rasio, N-total, P-tersedia, kalsium, natrium, kalium, kejenuhan basa, bobot isi, kadar air dan porositas. Kedua lahan memiliki kriteria IKT rendah namun GT memiliki nilai yang lebih tinggi (0,34) daripada GTT (0,27). Meskipun nilai IKT pada GT lebih tinggi, banyak dampak negatif yang ditimbulkan dari pembakaran lahan gambut. Karena itu pemerintah melarang pembakaran lahan dengan mengeluarkan kebijakan-kebijakan tentang pelarangan pembakaran hutan dan lahan gambut.AbstractPeatland fires cause changes in the physical, chemical and biological characteristics of the peat soil. It automatically affects the quality of the soil as stated by the Soil Quality Index (IKT). The purpose of this study was to determine the soil quality index and its determinants in burnt (GT) and unburnt (GTT) peatlands. The research was conducted in Bansir Darat Village, Southeast Pontianak District, Pontianak City on GT and GTT. The research stages included taking soil samples from each land, observing and measuring the depth of the peat, the thickness of the peat layer, the maturity of the peat and counting the number of worms as well. Analysis of soil physical characteristics including bulk density, moisture content of field capacity, total porosity; soil chemistry consists of C-organic, total nitrogen (N-total), CN ratio, available phosphorus (P-available), exchangeable sodium (Na-dd), potassium (K-dd), calcium-dd (Ca-dd)dan magnesium (Mg-dd), cation exchange capacity (CEC), base saturation (KB), content of ash; and the number of earth worms for soil biology property. The results showed that the physical characteristics of peat on GT had a shallower peat depth with sapric compared to GTT with hemic. The water content and porosity on GT are lower than GTT as well. The base cation of GT is higher than GTT even though the criteria for both are very low. The determinants of soil quality were C-organic, CN ratio, N-total, P-available, calcium, sodium, potassium, base saturation, content weight, moisture content and porosity. The Soil Quality Index of both lands have low criteria but GT has a higher value (0.34) than GTT (0.27). Even though the IKT value in GT is higher, there are many negative impacts caused by burning peatlands. Therefore, the government forbids burning of land by issuing policies to prohibit the burning of forests and peatlands.


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