No abstract

Plant phenology is affected by climate conditions and therefore provides a sensitive indicator to changes in climate. Studying the evolution and change in plant phenology aids in a better understanding of and predicting changes in ecosystems. Vegetation Indices (VIs) have been recognized for their utility in indicating vegetation activity. Understanding climatic variables and their relationship to VI support the knowledge base of how ecosystems are changing under a new climatic scenario. This study evaluates grassland growth phenology in the Biobio, Chile, biweekly with Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) time series. Four growth parameters for the six agro-climatic regions were analyzed from 2001 to 2020: start and end of the season, time and value of maximum NDVI. For this purpose, the NDVI time series were smoothed using Savitzky–Golay filtering. In addition, by using monthly gridded database climate data, we studied correlations between phenology markers and rainfall, maximum temperature and minimum temperature. The results show that both the start and end of the growing season did not significantly change; however, all agro-climatic regions grow faster and more vigorously. Thus, climatic conditions in Biobio have become more conducive to grassland growth over the 2001–2020 period.

No abstract

In Chile, indigenous forests (mostly Nothofagus sp. and Acacia caven ) and plantations of fast-growing exotic species cover 13.5 and 2.4 million ha, respectively. The latter consists principally of Pinus radiata and Eucalyptus sp., but also include cherry ( Prunus avium ), poplar ( Populus sp.), and walnut ( Juglans regia ). The main silvopastoral systems that have been established in the temperate zone of the country, excluding arid, semiarid and Patagonian regions, are in: (1) an old Nothofagus forest in the foothills of the Andes, (2) a second-growth "Roble" ( Nothofagus obliqua ) forests of the Andes, with the objectives of rejuvenating the overmature forests, and evaluating the quantity and quality of pasture that is sown under different tree coverages. The Pinus radiata -based silvopastoral systems are the most common system adopted by smallscale agroforestry producers in the Mediterranean Chile in diverse environments from semiarid to humid zones. Furthermore, because of the expanding markets for pine nuts and timber of several hardwood species, several experimental trials were established in the past 20 years between the Valparaiso and Los Lagos regions, including exotic species such as cherry, walnut, poplar and stone pine ( Pinus pinea ). Through regular income from the sale of diverse woody and non-woody forest products, these innovative silvopastoral