scholarly journals Aboveground Carbon Storage and Cycling of Flooded and Upland Forests of the Brazilian Pantanal

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 665
Author(s):  
Osvaldo Borges Pinto ◽  
Ana Carolina Amorim Marques ◽  
George L. Vourlitis

Tropical forests and savanna (cerrado) are important carbon (C) sinks; however, few data exist for seasonally flooded forests. We quantified the annual rates of aboveground net primary production (ANPP) over a five-year period for two forests, an upland mixed forest and a seasonally flooded cerrado forest, located in the northern Pantanal region of Brazil. We hypothesized that rates of ANPP would be higher for the mixed forest than the cerrado forest because seasonal flooding can limit rates of tree growth. ANPP was calculated as the sum of the annual litter production measured from litterfall traps and the stem growth increment measured from dendrometers and tree density. ANPP varied between 3.8–5.5 MgC ha−1 y−1 for the flooded forest and 1.6–4.6 MgC ha−1 y−1 for the upland forest. Litter production accounted for 57% of the ANPP, and the difference in ANPP between the upland and flooded forests was due to consistently higher litter production in the flooded forest. Annual variations in ANPP were not correlated with annual precipitation, presumably because the hydrology of these sites is driven more by the flood stage of the Cuiaba River than by local precipitation. However, consistent declines in forest floor litter mass occurred at both sites, suggesting that C storage may be responding to some unknown disturbance that occurred prior to our sampling campaign. Seasonal variation in rainfall exerted an important control on litter production dynamics, with leaf litter production increasing during the dry season and stem and reproductive litter production increasing during the wet season. While there are few studies of seasonally flooded tropical forests, our data suggest that the seasonally flooded and upland forests of the northern Pantanal can act as appreciable aboveground C sinks.

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.


2020 ◽  
Author(s):  
Raphael Manu ◽  
Marife D. Corre ◽  
Edzo Veldkamp ◽  
Oliver van Straaten

<p>Nutrient availability in tropical forest ecosystems plays a critical role in sustaining forest growth and productivity. Observational evidence for nutrient limitations on net primary productivity (NPP) in the tropics is rare yet crucial for predicting the impacts of human-induced changes on tropical forests, particularly for underrepresented tropical regions in Africa. In an ecosystem-scale nutrient manipulation experiment, we assessed the response of different components of above-ground net primary production (ANPP) to nutrient addition of nitrogen (N), phosphorus (P), potassium (K) and all possible combinations (NP, NK, PK, and NPK) at rates of 125 kg N ha<sup>-1</sup>yr<sup>-1</sup>, 50 kg P ha<sup>-1</sup> yr<sup>-1</sup> and 50 kg K ha<sup>-1</sup>yr<sup>-1</sup>.</p><p>We established 32 (8 treatments × 4 replicates) experimental plots of 40 × 40 m<sup>2</sup> each and measured stem growth of over 15,000 trees with diameter at breast height (dbh) ≥ 1 cm as well as litter production and above-ground woody biomass production (AWBP), of a lower-montane tropical forest (1100 m a.s.l.) in northwestern Uganda.</p><p>After 18 months of nutrient addition, we found that different aspects of ANPP, including litter production and AWBP are controlled by multiple soil nutrients. Specifically, we measured higher total fine-litter production in the N (13.6 ± 1.4 Mg ha<sup>-1 </sup>yr<sup>-1</sup>) and K (13.3 ± 1.8 Mg ha<sup>-1 </sup>yr<sup>-1</sup>) addition plots than the control (11.1 ± 0.6 Mg ha<sup>-1 </sup>yr<sup>-1</sup>) plots. Both reproductive litter (flowers and fruits; 10% of total fine-litter fall) and leaf litter (62% of total fine-litter fall) significantly increased with K addition. In general, fine-litter production in our plots is higher than what has been reported so far for lower-montane tropical forests. Increased AWBP is associated with N addition plots. The response of trees to nutrient addition however, varied with tree sizes. Trees with dbh between 10 – 30 cm increased significantly in AWBP under PK addition. There was no effect of nutrient addition associated with either smaller (1 – 10 cm dbh) or larger trees (dbh > 30 cm). The medium-sized trees which may have experienced resource competition but have now transitioned into the canopy layer (exposed to sunlight) are able to use additional nutrient for active growth. In contrast, bigger trees may allocate extra nutrient for reproduction and leaf-vitality, while smaller trees remain shaded, co-limited by sunlight and therefore unable to utilize increased available nutrients for stem diameter growth. ANPP increased by 39% with N addition and marginally by 23% with K additions relative to the control. In conclusion, our experiment provides evidence of N and potentially K limitation of ANPP in this lower-montane tropical forest, and highlights that, in a highly diverse ecosystem different components of ANPP may be regulated by multiple nutrients. </p>


Author(s):  
Ludymilla Barbosa da Silva ◽  
Jonathan Willian Zangeski Novais ◽  
Luciana Sanches ◽  
Nadja Gomes Machado ◽  
Aryadne Marcia Aquino ◽  
...  

Áreas naturais alagadas estão entre os ecossistemas com alta produtividade e são amplamente distribuídas no mundo. O Pantanal se constitui uma das maiores planícies inundáveis contínuas do mundo e cerca de 30% da sua área compreende florestas sazonalmente inundáveis. Nesse sentido, o presente trabalho visa contribuir para a compreensão de processos pouco estudados nas florestas inundáveis como a serrapilheira, e efluxo de CO2 no solo, ambos influenciados pelas cheias pantaneiras. Tendo em vista a importância desses ecossistemas florestais, o objetivo geral deste trabalho foi analisar a dinâmica de serrapilheira e efluxo de CO2 em uma floresta sazonalmente inundável no Pantanal Mato- Grossense. Foram monitorados 55 pontos em 5 transectos para medições de efluxo de CO2, IAF e umidade do solo, além de 20 coletores de 1m2 para coletas de serrapilheira. A média de produção mensal de serrapilheira foi de 1005 g m-2 para litterpool e 213 g m-2 para a litterfall. A média anual do efluxo foi de 1,11 g CO2 m-2 h-1, ocorrendo em setembro o menor valor, mês mais seco, 0,691 g CO2 m-2 h-1. Houve sazonalidade característica para todas as variáveis analisadas, sendo a diminuição da umidade do solo fator determinante para a produção de serrapilheira e inibição do efluxo de CO2 do solo.Palavras-chaves: Litterpool. Litterfall. Dióxido de Carbono. Respiração do Solo. Vochysia Divergens Phol.AbstractFlooded natural areas are among the ecosystems with high ecological productivity and are widely distributed in the world. Pantanal is one of the largest continuous floodplains in the world and about 30% of its area comprises seasonally flooded forests. In this sense, the present work aims to contribute to the understanding of processes that are not studied in the floodplain forests, such as litter, and CO2 efflux in the soil, both influenced by the floods pulse. Considering the importance of these forest ecosystems, the general objective of this work was to analyze the litter dynamics and CO2 efflux in a seasonally flooded forest in Mato Grosso Pantanal. Fifty-five points were monitored in 5 transects for measurements of CO2 efflux, LAI and soil moisture, and 20 collectors of 1m2 for litter collection. The average monthly litter yield was 1005 g m-2 for litterpool and 213 g m-2 for litterfall. The annual average of the efflux was 1.11 g CO2 m-2 h-1, occurring in September the lowest value, the driest month, 0.691 g CO2 m-2 h-1. There was a characteristic seasonality for all analyzed variables, being the decrease of the soil moisture determining factor for litter production and inhibition of soil CO2 efflux.Keywords: Litterpool. Litterfall. Carbon Dioxide. Soil Respiration. Vochysia Divergens Phol.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 349
Author(s):  
Andrés Baietto ◽  
Jorge Hernández ◽  
Amabelia del Pino

The replacement of native pasture by exotic commercial forest species is an infrequent situation worldwide. In these systems, a new component is introduced, forest litter, which constitutes one of the main ways of incorporating carbon into the soil–plant system. The present work seeks to establish a methodological approach to study the dynamics of litter production and decomposition in an integrated way. The general objective was to characterize and compare the litter production dynamics in 14-year-old Eucalyptus grandis Hill ex Maiden and Pinus taeda L. commercial plantations. During two years, seasonal evaluations of fall, decomposition and accumulation of litter were carried out in stands of both species. In turn, the contribution of carbon from forest species to the soil through isotopic analysis techniques was quantified. Litterfall in E. grandis showed maximums during the spring of the first year and in the spring and summer of the second. In P. taeda, the maximums occurred in summer of the first year and in autumn of the second. In relation to the decomposition rate, the results based on short periods of evaluation between 15 and 21 months did not show differences between species, nor for the different moments of beginning of the evaluation, obtaining average values of 0.0369 month−1 for E. grandis and 0.0357 month−1 for P. taeda. In turn, both the decomposition rate of the material as a whole and the estimates of accumulated biomass in equilibrium state did not show significant differences between the species. Additionally, there was a relevant incorporation of carbon into the soil by forest species, fundamentally in the first few centimeters, substituting an important proportion of the carbon inherited by the original cover of native pastures. Finally, it is necessary to specify that the scope of the findings obtained is greatly limited by the sample size used in this study.


2015 ◽  
Vol 112 (43) ◽  
pp. 13267-13271 ◽  
Author(s):  
Geertje M. F. van der Heijden ◽  
Jennifer S. Powers ◽  
Stefan A. Schnitzer

Tropical forests store vast quantities of carbon, account for one-third of the carbon fixed by photosynthesis, and are a major sink in the global carbon cycle. Recent evidence suggests that competition between lianas (woody vines) and trees may reduce forest-wide carbon uptake; however, estimates of the impact of lianas on carbon dynamics of tropical forests are crucially lacking. Here we used a large-scale liana removal experiment and found that, at 3 y after liana removal, lianas reduced net above-ground carbon uptake (growth and recruitment minus mortality) by ∼76% per year, mostly by reducing tree growth. The loss of carbon uptake due to liana-induced mortality was four times greater in the control plots in which lianas were present, but high variation among plots prevented a significant difference among the treatments. Lianas altered how aboveground carbon was stored. In forests where lianas were present, the partitioning of forest aboveground net primary production was dominated by leaves (53.2%, compared with 39.2% in liana-free forests) at the expense of woody stems (from 28.9%, compared with 43.9%), resulting in a more rapid return of fixed carbon to the atmosphere. After 3 y of experimental liana removal, our results clearly demonstrate large differences in carbon cycling between forests with and without lianas. Combined with the recently reported increases in liana abundance, these results indicate that lianas are an important and increasing agent of change in the carbon dynamics of tropical forests.


2012 ◽  
Vol 42 (4) ◽  
pp. 561-566 ◽  
Author(s):  
Janette Noveras ◽  
Kedma C. Yamamoto ◽  
Carlos E.C. Freitas

We evaluated diversity and distribution of fish species in two habitats: flooded forest and open water of lakes of Rio Negro. Each of four lakes within the Anavilhanas Archipelago was sampled three times from 2009-2010. Species diversity generally was higher in flooded forests and at night, according to correspondence analysis. Predators were most active at night, but showed no preference between the flooded forest and open water habitats. Omnivores, filter feeders, and detritivores were most active during the day.


2005 ◽  
Vol 26 (4) ◽  
pp. 431-435 ◽  
Author(s):  
Savitha Krishna ◽  
Sharath Krishna

AbstractWe noticed an uncommon phenomenon of female vocalization in the forest litter frog, Rana curtipes during the breeding season. We digitally recorded the male and female vocalization of the litter frogs in the tropical rain forests of the Western Ghats of South India and analyzed the call characteristics. The female call varied from the male call by being single note in composition. In contrast, the male calls were composed of seven to eight notes and longer in duration. We observed that gravid females, occupying the same location every day, emitted low volume calls when numerous males were found calling at that time. Some females arrived asynchronously and called even in the absence of males possibly to declare their receptive condition. Calling females responded agonistically to receptive conspecifics of the same sex. In addition to declaring receptivity, this calling behavior may be a response to adjacent competing females when the males are few.


2011 ◽  
Vol 3 (5) ◽  
pp. 18-23
Author(s):  
Jolita Dūdaitė ◽  
Edita Baltrėnaitė ◽  
Paulo Pereira ◽  
Xavier Úbeda

Research was carried out to identify the influence of temperature (150, 250, 350, 450, 550ºC) on the ash colour of Acer platanoides L. leaf litter and Pinus sylvestris L. needle litter samples collected from deciduous coniferous mixed forest in Lithuania (54º43‘ N 25º19‘ E) in April 2010. To achieve the objective, a laboratory experiment was conducted to determine ash samples using the Munsell Colour Chart. The analysis of colours has demonstrated that considering all litter samples, an increase in the temperature of litter heating was found to increase ash colour values (r = 0.92; p = 0.01). All the samples (n = 50) of both litter species were divided into categories 2.5Y (5 samples), 7.5YR (10 samples) and 10YR (35 samples). The total black Munsell colour was observed at a temperature of 350ºC for both litter species. Needle ash started turning bright at a temperature of 550ºC while the complete consumption of leaf litter was visible at a temperature of 450ºC. We conclude that the Munsell Colour Chart used for predicting the colour of ash is an informative feature to have the primary classification of ash. It is imperative to analyse the colour of the litter ash of the selected tree species in order to quickly and easily assess and predict their possible impact on the surrounding environment. Santrauka Tyrimas atliktas siekiant nustatyti temperatūros įtaką (150, 250, 350, 450, 550 ºC) paprastosios pušies spyglių ir paprastojo klevo lapų, surinktų iš lapuočių ir spygliuočių mišraus miško Lietuvoje (54° 43 „N 25° 19 ‚E) 2010-ųjų balandį, pelenų spalvai. Laboratorijoje Munsell spalvų sistema buvo naudojama, norint nustatyti pelenų spalvos reikšmes. Tyrimas parodė, kad didinant degimo temperatūrą visų pelenų spalvų vertės atitinkamai didėjo (r = 0,92, p = 0,01). Pagal spalvų skalę visus mėginius (50) galima suskirstyti į kategorijas: 2.5Y (5 mėginiai), 7.5YR (10 mėginių) ir 10YR (35 mėginiai). Juoda spalva buvo stebima abiejų rūšių pelenuose, kurie buvo deginami 350 ºC temperatūroje. Spyglių pelenai tapo šviesūs esant 550 ºC temperatūrai, o šviesėjantys lapų pelenai pastebėti 450 ºC temperatūroje. Galime teigti, kad Munsell spalvų sistemos naudojimas pelenų spalvai nustatyti yra informatyvus pirminės pelenų klasifikacijos rodiklis.


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