δ13C in Pentaclethra macroloba trees growing at forest edges in north-eastern Costa Rica

2008 ◽  
Vol 24 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Jessica L. Schedlbauer ◽  
Kathleen L. Kavanagh

AbstractFragmented forest landscapes with large proportions of edge area are common in the tropics, though little is known about functional responses of trees to edge effects. Foliar δ13C can increase our understanding of tree function, as these values reflect changes in ci/ca as trees respond to environmental gradients. We expected that foliar δ13C would be enriched, indicating a decline in ci/ca, in Pentaclethra macroloba trees growing at forest edges in north-eastern Costa Rica. We also anticipated this isotopic shift in δ13C values of soil carbon and soil respired CO2. Three transects perpendicular to forest edges were established at three study sites, and six plots per transect were located 0–300 m from edges. Within plots, foliage, soil and soil respired CO2 were collected for isotopic analyses. Foliar δ13C, thus ci/ca, and soil carbon δ13C did not vary along the edge to interior gradient. δ13C for canopy and understorey foliage averaged −29.7‰ and −32.5‰, respectively, while soil carbon δ13C averaged −28.0‰. Soil respired CO2 δ13C ranged from −29.2‰ to −28.6‰ and was significantly depleted within 50 m of edges. The predominant lack of functional responses at forest edges indicates that P. macroloba trees are robust and these forests are minimally influenced by edge effects.

Author(s):  
Alejandra Pérez Enríquez ◽  
Roberto Cordero ◽  
Elizabeth Braker

La combinación de rasgos como la fijación de nitrógeno en plantas tropicales con otros rasgos como disponibilidad nutricional podría incidir en el éxito de algunas especies para su establecimiento y desarrollo. Otras interacciones como la herbivoría podrían cambiar sutilmente estas relaciones y llegar a ser relevantes para su éxito ecológico. Sometimos brinzales de Pentaclethra macroloba (Gavilán, Fabaceae) en macetas, con y sin adición de nutrientes y a la interacción con defoliación controlada (herbivoría artificial), en el sotobosque secundario dentro de un bosque de Sarapiquí, Costa Rica. La biomasa total muestra una fuerte compensación neta y la defoliación indujo una mayor asignación al follaje. La fertilización siempre resultó en menos asignación a nódulos. La esbeltez respondió a ambos factores de manera sinergística. Sugerimos que la herbivoría puede ocasionar cambios importantes en la manera en que las especies asignan sus recursos en concordancia con sus simbiosis y la disponibilidad de nutrientes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiliang Song ◽  
Yihao Zhu ◽  
Weifeng Chen

AbstractThe soil carbon (C) pools in coastal wetlands are known as “blue C” and have been damaged extensively owing to climate change and land reclamation. Because soil respiration (RS) is the primary mechanism through which soil carbon is released into the atmosphere at a global scale, investigating the dynamic characteristics of the soil respiration rate in reclaimed coastal wetlands is necessary to understand its important role in maintaining the global C cycle. In the present study, seasonal and diurnal changes in soil respiration were monitored in one bare wetland (CK) and two reclaimed wetlands (CT, a cotton monoculture pattern, and WM, a wheat–maize continuous cropping pattern) in the Yellow River Delta. At the diurnal scale, the RS at the three study sites displayed single-peak curves, with the lowest values occurring at midnight (00:00 a.m.) and the highest values occurring at midday (12:00 a.m.). At the seasonal scale, the mean diurnal RS of the CK, CT and WM in April was 0.24, 0.26 and 0.79 μmol CO2 m−2 s−1, and it increased to a peak in August for these areas. Bare wetland conversion to croplands significantly elevated the soil organic carbon (SOC) pool. The magnitude of the RS was significantly different at the three sites, and the yearly total amounts of CO2 efflux were 375, 513 and 944 g CO2·m−2 for the CK, CT and WM, respectively. At the three study sites, the surface soil temperature had a significant and positive relationship to the RS at both the diurnal and seasonal scales, and it accounted for 20–52% of the seasonal variation in the daytime RS. The soil water content showed a significant but negative relationship to the RS on diurnal scale only at the CK site, while it significantly increased with the RS on seasonal scale at all study sites. Although the RS showed a noticeable relationship to the combination of soil temperature and water content, the synergic effects of these two environment factors were not much higher than the individual effects. In addition, the correlation analysis showed that the RS was also influenced by the soil physico-chemical properties and that the soil total nitrogen had a closer positive relationship to the RS than the other nutrients, indicating that the soil nitrogen content plays a more important role in promoting carbon loss.


PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e97036 ◽  
Author(s):  
Nélida R. Villaseñor ◽  
Don A. Driscoll ◽  
Martín A. H. Escobar ◽  
Philip Gibbons ◽  
David B. Lindenmayer

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lawrence H. Tanner ◽  
Megan T. Wilckens ◽  
Morgan A. Nivison ◽  
Katherine M. Johnson

We measured carbon stocks at two forest reserves in the cloud forest region of Monteverde, comparing cleared land, experimental secondary forest plots, and mature forest at each location to assess the effectiveness of reforestation in sequestering biomass and soil carbon. The biomass carbon stock measured in the mature forest at the Monteverde Institute is similar to other measurements of mature tropical montane forest biomass carbon in Costa Rica. Local historical records and the distribution of large trees suggest a mature forest age of greater than 80 years. The forest at La Calandria lacks historical documentation, and dendrochronological dating is not applicable. However, based on the differences in tree size, above-ground biomass carbon, and soil carbon between the Monteverde Institute and La Calandria sites, we estimate an age difference of at least 30 years of the mature forests. Experimental secondary forest plots at both sites have accumulated biomass at lower than expected rates, suggesting local limiting factors, such as nutrient limitation. We find that soil carbon content is primarily a function of time and that altitudinal differences between the study sites do not play a role.


2016 ◽  
Vol 10 (1) ◽  
pp. 123-132
Author(s):  
Ewa Labak-Mechowska

Abstract Subsurface sediments in Poland were deposited mainly in the Pleistocene, and have varying origins and, consequently, differing geological and engineering parameters. Fluvioglacial deposits were formed during both the glacial and interglacial periods, which differed from each other in climatic conditions. Based on the results of laboratory analysis and fieldwork, till and fluvioglacial sands were compared in Central and North-Eastern Poland. The research included consistency limits, relative density, plasticity index, constrained modulus of initial compressibility and modulus of initial deformation. Despite the existing view that there exists a large diversity of geological, engineering and geotechnical parameters of variously-aged deposits in Poland, no major differences in their properties were determined at the study sites.


Primates ◽  
2018 ◽  
Vol 59 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Laura M. Bolt ◽  
Amy L. Schreier ◽  
Kristofor A. Voss ◽  
Elizabeth A. Sheehan ◽  
Nancy L. Barrickman ◽  
...  
Keyword(s):  

CATENA ◽  
2020 ◽  
Vol 194 ◽  
pp. 104785 ◽  
Author(s):  
Subhash Babu ◽  
K.P. Mohapatra ◽  
Gulab Singh Yadav ◽  
Rattan Lal ◽  
Raghavendra Singh ◽  
...  

Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 25 ◽  
Author(s):  
Zsolt Tóth ◽  
Elisabeth Hornung

Urbanization, as a major cause of local species extinction and biotic homogenization, drastically alters soil life. Millipedes are a key group of soil macrodetritivores and significantly influence soil quality, mainly through their essential role in nutrient cycling. Therefore, studying their taxonomic and functional responses to urban disturbance is crucial, as they contribute to the provision of several soil-related ecosystem services in cities. Differently degraded rural, urban forests and other woody patches (e.g., parks, gardens, and cemeteries) were sampled on Buda and Pest sides of the Budapest metropolitan area divided by the Danube River. We measured the most relevant physical and chemical properties of topsoil to characterize habitats. We applied an urbanization index based on vegetation cover and built-up area of the study sites to quantify urban intensity. The composition of the assemblages was determined by the division of the city along the Danube. Urbanization was associated with a reduction in species and functional richness of millipedes on both sides of Budapest. β diversity and species turnover increased with urban intensity. Urban disturbance was the main driver in assembly of taxonomic and functional community composition. A new species (Cylindroiulus caeruleocinctus (Wood, 1864)) to the fauna of Budapest was found. Detritivore invertebrates depend on leaf litter and other dead organic matter types, therefore microsites providing these resources greatly improve their survival. Due to increasing urban disturbance, it is recommended to provide appropriate detritus and shelter sites as part of the management of green spaces in order to maintain species richness, abundance, and function of species.


2019 ◽  
Vol 474 (474) ◽  
pp. 31-42
Author(s):  
Aleksandra Kozłowska

Carbonate minerals in the Middle Jurassic sideritic rocks from the Polish Lowlands, north-eastern margin of the Holy Cross Mountains and the Częstochowa region have been studied applying accessible instrumental methods. The following techniques were applied: polarization microscope, staining with the Evamy’s solution, cathodoluminescence, microprobe, fluid inclusions and isotopic analyses. Most of these methods were not available either in the 20ies of the past century when studies of sideritic iron ores in Poland had begun, or in 50ies and 60ies when they were in full progress. The sideritic rocks are mainly represented by clayey siderites (they contain also muddy and sandy varieties), sideritic sandstones and sideritic coquina, less frequently by sideritic conglomerates and mudstones. Sideroplesite is the main carbonate mineral that builds the sideritic rocks, while pistomesite and siderite are less frequent. Fe-calcite and Fe-dolomite, ankerite, and sporadic dolomite occur in lesser amounts. Syderoplesite and siderite have crystallized in the early diagenesis (eodiagenesis), in the zone of microbiologic methanogenesis, at temperatures of about 20°C, from the porous waters of marine origin, or from marine waters mixed with fresh waters. Sideroplesite enriched in magnesium, pistomesite, calcite and ankerite sequently have formed at the later diagenetic stage (mezodiagenesis). These minerals have crystallized at temperatures above 60°C, from the porous waters of marine origin, or from the fluid which interacted with the adjacent rocks. Fe-calcite was formed in the zone of microbiologic methanogenesis, while the ankerite – in the zone of thermal decarboxylation.


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