Evaluación de gases efecto invernadero en la cuenca atmosférica del Valle del Cusco

El presente trabajo de investigación fue realizado en la cuenca atmosférica del valle del Cusco en los periodos de enero 2010 a enero 2012 estableciendo 9 puntos de muestreo en los principales focos emisores de la cuenca atmosférica del valle del Cusco, como: Piñipampa, Huacarpay-Lucre, Oropesa, Pillao Matao, Diresa Cusco (Av. De la Cultura), Serpost (Av. El Sol), Plaza de Armas del Cusco, San Luis -Aeropuerto (San Sebastián), San Benito (Tica Tica). Se evaluaron los principales gases efecto invernadero como: C02, N20, S02 y H2S. Se utilizaron métodos: gravimétricos, espectrometría visible y de absorción atómica. Como resultados de las evaluaciones se obtiene que la concentración máxima de C02 se registra en el punto de muestreo 7 (Plaza de Armas del Cusco) con 67 ppm, en segundo lugar el punto de muestreo 6 (SERPOST) con 64 ppm, en tercer lugar el punto de muestreo 8 (San Luis Aeropuerto) con 63 ppm, obteniendo menores concentraciones. en los puntos de muestreo restantes. El nivel promedio de C02 para la cuenca atmosférica del valle del Cusco es de 40 ppm; y por cada 0.042 ppm de C02 en promedio la temperatura se incrementa en 1°C, y por cada 5.44 ppm de C02 la precipitación se incrementara en 1 mm. Para N20 la concentración máxima se encuentra en el punto de muestreo 9 (San Benito - Arco Tica) con 19 µg/m3, en segundo lugar el punto de muestreo 1 (Piñipampa) con 13 µg/m3, en tercer lugar el punto de muestreo 3 (Oropesa) con 12 µg/m3, obteniendo menores concentraciones en los puntos de muestreo restantes. El nivel N20 promedio para la cuenca atmosférica del valle de Cusco es de 14 µg/m3. Donde por cada 0.35 µg/m3 de incremento de N20 la temperatura se incrementa en 1 oc, y por cada 3.3 µg/m3 de incremento la precipitación disminuye en 1 mm.Tesi

The productivity, metabolism and carbon cycle of two lowland tropical forest plots in south-western Amazonia

Background: The forests of western Amazonia are known to be more dynamic that the better-studied forests of eastern Amazonia, but there has been no comprehensive description of the carbon cycle of a western Amazonian forest. Aims: We present the carbon budget of two forest plots in Tambopata in south-eastern Peru, western Amazonia. In particular, we present, for the first time, the seasonal variation in the detailed carbon budget of a tropical forest. Methods: We measured the major components of net primary production (NPP) and total autotrophic respiration over 3-6 years. Results: The NPP for the two plots was 15.1 ± 0.8 and 14.2 ± 1.0 Mg C ha −1 year −1 , the gross primary productivity (GPP) was 35.5 ± 3.6 and 34.5 ± 3.5 Mg C ha −1 year −1 , and the carbon use efficiency (CUE) was 0.42 ± 0.05 and 0.41 ± 0.05. NPP and CUE showed a large degree of seasonality. Conclusions: The two plots were similar in carbon cycling characteristics despite the different soils, the most notable difference being high allocation of NPP to canopy and low allocation to fine roots in the Holocene floodplain plot. The timing of the minima in the wet-dry transition suggests they are driven by phenological rhythms rather than being driven directly by water stress. When compared with results from forests on infertile forests in humid lowland eastern Amazonia, the plots have slightly higher GPP, but similar patterns of CUE and carbon allocation

Evaluación de gases efecto invernadero en la cuenca atmosférica del Valle del Cusco

TesisEl presente trabajo de investigación fue realizado en la cuenca atmosférica del valle del Cusco en los periodos de enero 2010 a enero 2012 estableciendo 9 puntos de muestreo en los principales focos emisores de la cuenca atmosférica del valle del Cusco, como: Piñipampa, Huacarpay-Lucre, Oropesa, Pillao Matao, Diresa Cusco (Av. De la Cultura), Serpost (Av. El Sol), Plaza de Armas del Cusco, San Luis -Aeropuerto (San Sebastián), San Benito (Tica Tica). Se evaluaron los principales gases efecto invernadero como: C02, N20, S02 y H2S. Se utilizaron métodos: gravimétricos, espectrometría visible y de absorción atómica. Como resultados de las evaluaciones se obtiene que la concentración máxima de C02 se registra en el punto de muestreo 7 (Plaza de Armas del Cusco) con 67 ppm, en segundo lugar el punto de muestreo 6 (SERPOST) con 64 ppm, en tercer lugar el punto de muestreo 8 (San Luis Aeropuerto) con 63 ppm, obteniendo menores concentraciones. en los puntos de muestreo restantes. El nivel promedio de C02 para la cuenca atmosférica del valle del Cusco es de 40 ppm; y por cada 0.042 ppm de C02 en promedio la temperatura se incrementa en 1°C, y por cada 5.44 ppm de C02 la precipitación se incrementara en 1 mm. Para N20 la concentración máxima se encuentra en el punto de muestreo 9 (San Benito - Arco Tica) con 19 µg/m3, en segundo lugar el punto de muestreo 1 (Piñipampa) con 13 µg/m3, en tercer lugar el punto de muestreo 3 (Oropesa) con 12 µg/m3, obteniendo menores concentraciones en los puntos de muestreo restantes. El nivel N20 promedio para la cuenca atmosférica del valle de Cusco es de 14 µg/m3. Donde por cada 0.35 µg/m3 de incremento de N20 la temperatura se incrementa en 1 oc, y por cada 3.3 µg/m3 de incremento la precipitación disminuye en 1 mm

The productivity, metabolism and carbon cycle of two lowland tropical forest plots in south-western Amazonia, Peru

Background: The forests of western Amazonia are known to be more dynamic that the better-studied forests of eastern Amazonia, but there has been no comprehensive description of the carbon cycle of a western Amazonian forest. Aims: We present the carbon budget of two forest plots in Tambopata in south-eastern Peru, western Amazonia. In particular, we present, for the first time, the seasonal variation in the detailed carbon budget of a tropical forest. Methods: We measured the major components of net primary production (NPP) and total autotrophic respiration over 3-6 years. Results: The NPP for the two plots was 15.1 ± 0.8 and 14.2 ± 1.0 Mg C ha-1 year-1, the gross primary productivity (GPP) was 35.5 ± 3.6 and 34.5 ± 3.5 Mg C ha-1 year-1, and the carbon use efficiency (CUE) was 0.42 ± 0.05 and 0.41 ± 0.05. NPP and CUE showed a large degree of seasonality. Conclusions: The two plots were similar in carbon cycling characteristics despite the different soils, the most notable difference being high allocation of NPP to canopy and low allocation to fine roots in the Holocene floodplain plot. The timing of the minima in the wet-dry transition suggests they are driven by phenological rhythms rather than being driven directly by water stress. When compared with results from forests on infertile forests in humid lowland eastern Amazonia, the plots have slightly higher GPP, but similar patterns of CUE and carbon allocation

Seasonal production, allocation and cycling of carbon in two mid-elevation tropical montane forest plots in the Peruvian Andes

Background: Tropical montane cloud forests (TMCF) are unique ecosystems with high biodiversity and large carbon reservoirs. To date there have been limited descriptions of the carbon cycle of TMCF. Aims: We present results on the production, allocation and cycling of carbon for two mid-elevation (1500-1750 m) tropical montane cloud forest plots in San Pedro, Kosnipata Valley, Peru. Methods: We repeatedly recorded the components of net primary productivity (NPP) using biometric measurements, and autotrophic (R-a) and heterotrophic (Rh) respiration, using gas exchange measurements. From these we estimated gross primary productivity (GPP) and carbon use efficiency (CUE) at the plot level. Results: The plot at 1500 m was found very productive, with our results comparable with the most productive lowland Amazonian forests. The plot at 1750 m had significantly lower productivity, possibly because of greater cloud immersion. Both plots had similar patterns of NPP allocation, a substantial seasonality in NPP components and little seasonality in R-a. Conclusions: These two plots lie within the ecotone between lower and upper montane forests, near the level of the cloud base. Climate change is likely to increase elevation of the cloud base, resulting in shifts in forest functioning. Longer-term surveillance of the carbon cycle at these sites would yield valuable insights into the response of TMCFs to a shifting cloud base

Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical forests

Abstract The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phosphorus, and secondly, that the estimated herbivore-mediated flux of foliar nitrogen and phosphorus from plants to soil via leaf area loss is similar to, or greater than, other major sources of these nutrients in tropical forests. Finally, we estimate that herbivores consume a significant portion of plant carbon, potentially causing major shifts in the pattern of plant and soil carbon cycling. We conclude that future shifts in herbivore abundance and activity as a result of environmental change could have major impacts on soil fertility and ecosystem carbon sequestration in tropical forests

The productivity, metabolism and carbon cycle of two lowland tropical forest plots in south-western Amazonia, Peru

<div><p> <b><i>Background:</i></b> The forests of western Amazonia are known to be more dynamic that the better-studied forests of eastern Amazonia, but there has been no comprehensive description of the carbon cycle of a western Amazonian forest.</p> <p> <b><i>Aims:</i></b> We present the carbon budget of two forest plots in Tambopata in south-eastern Peru, western Amazonia. In particular, we present, for the first time, the seasonal variation in the detailed carbon budget of a tropical forest.</p> <p> <b><i>Methods:</i></b> We measured the major components of net primary production (NPP) and total autotrophic respiration over 3–6 years.</p> <p> <b><i>Results:</i></b> The NPP for the two plots was 15.1 ± 0.8 and 14.2 ± 1.0 Mg C ha⁻¹ year⁻¹, the gross primary productivity (GPP) was 35.5 ± 3.6 and 34.5 ± 3.5 Mg C ha⁻¹ year⁻¹, and the carbon use efficiency (CUE) was 0.42 ± 0.05 and 0.41 ± 0.05. NPP and CUE showed a large degree of seasonality.</p> <p> <b><i>Conclusions:</i></b> The two plots were similar in carbon cycling characteristics despite the different soils, the most notable difference being high allocation of NPP to canopy and low allocation to fine roots in the Holocene floodplain plot. The timing of the minima in the wet–dry transition suggests they are driven by phenological rhythms rather than being driven directly by water stress. When compared with results from forests on infertile forests in humid lowland eastern Amazonia, the plots have slightly higher GPP, but similar patterns of CUE and carbon allocation.</p> </div

Productivity and carbon allocation in a tropical montane cloud forest in the Peruvian Andes

<div><p> <b><i>Background:</i></b> The slopes of the eastern Andes harbour some of the highest biodiversity on Earth and a high proportion of endemic species. However, there have been only a few and limited descriptions of carbon budgets in tropical montane forest regions.</p> <p> <b><i>Aims:</i></b> We present the first comprehensive data on the production, allocation and cycling of carbon for two high elevation (ca. 3000 m) tropical montane cloud forest plots in the Kosñipata Valley, Peruvian Andes.</p> <p> <b><i>Methods:</i></b> We measured the main components and seasonal variation of net primary productivity (<i>NPP</i>), autotrophic (<i>R</i>_a) and heterotrophic (<i>R</i>_h) respiration to estimate gross primary productivity (<i>GPP</i>) and carbon use efficiency (<i>CUE</i>) in two 1-ha plots.</p> <p> <b><i>Results:</i></b><i>NPP</i> for the two plots was estimated to be 7.05 ± 0.39 and 8.04 ± 0.47 Mg C ha⁻¹ year⁻¹, <i>GPP</i> to be 22.33 ± 2.23 and 26.82 ± 2.97 Mg C ha⁻¹ year⁻¹ and <i>CUE</i> was 0.32 ± 0.04 and 0.30 ± 0.04.</p> <p> <b><i>Conclusions:</i></b> We found strong seasonality in <i>NPP</i> and moderate seasonality of <i>R</i>_a, suggesting that forest <i>NPP</i> is driven by changes in photosynthesis and highlighting the importance of variation in solar radiation. Our findings imply that trees invest more in biomass production in the cooler season with lower solar radiation and more in maintenance during the warmer and high solar radiation period.</p> </div