RESUMO
Durante el período 2000 - 2016, se llevaron a cabo 15 inventarios biológicos en áreas remotas en el pie de monte andino y el llano amazónico del Perú. En estos inventarios, 27 botánicos colectaron un total de 9397 especímenes de plantas vasculares fértiles. Hasta finales del 2017, más de la mitad de estos especímenes se han identificado a nivel de especie, de los cuales 64 especies y 2 géneros (Dicorynia y Monopteryx) representan nuevos registros para la flora del Perú. Si esta tasa de novedades se mantiene, el número de registros nuevos en el material de los inventarios podría aumentar, lo cual nos indica que aún queda mucho por descubrir en la flora andino-amazónica del Perú.
Between 2000 and 2016 we carried out 15 rapid biological inventories in remote areas of the Andean foothills and Amazon basin in Peru. During these inventories, 27 botanists collected 9397 fertile vascular plant specimens. By the end of 2017, more than half of these specimens had been identified to species. Of the 2303 species identified to date, 64 species and 2 genera (Dicorynia and Monopteryx) are new records for the flora of Peru. If this rate of discovery proves typical, the number of new records for Peru in the rapid inventory material could increase, which indicates that there is still much to discover in the Peruvian flora.
RESUMO
Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site-to-site variations in GPP have little power in explaining site-to-site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling.
Assuntos
Ciclo do Carbono , Florestas , Fotossíntese , Árvores/crescimento & desenvolvimento , Árvores/metabolismo , Animais , Biomassa , Carbono/metabolismo , Secas , Modelos Teóricos , América do Sul , Clima TropicalRESUMO
A better understanding of the mechanisms controlling the magnitude and sign of carbon components in tropical forest ecosystems is important for reliable estimation of this important regional component of the global carbon cycle. We used the JULES vegetation model to simulate all components of the carbon balance at six sites along an Andes-Amazon transect across Peru and Brazil and compared the results to published field measurements. In the upper montane zone the model predicted a lack of forest vegetation, indicating a need for better parameterization of the responses of cloud forest vegetation within the model. In the lower montane and lowland zones simulated ecosystem productivity and respiration were predicted with reasonable accuracy, although not always within the error bounds of the observations. Model-predicted carbon use efficiency in this transect surprisingly did not increase with elevation, but remained close to the 'temperate' value 0.5. Upper montane forests were predicted to allocate ~50% of carbon fixation to biomass maintenance and growth, despite available measurements showing that they only allocate ~33%. This may be explained by elevational changes in the balance between growth and maintenance respiration within the forest canopy, as controlled by both temperature- and pressure-mediated processes, which is not yet well represented in current vegetation models.
RESUMO
La agricultura de estos últimos años requiere del uso de muchos insumos para mejorar la producción de los cultivos, por esta razón a esta actividad en la actualidad se le considera como una de las que ocasionan el mayor impacto por el uso de fertilizantes químicos, nematicidas, insecticidas, fungicidas, herbicidas entre otros, siendo la localidad de Curahuasi, uno de los valles interandinos con mayor actividad agrícola del Departamento de Apurímac, donde se logra dos cosechas al año, ha merecido la atención mediante el presente proyecto.
