The LTER (Long-Term Ecological Research) is a network of sites, on a large spatial scale, where the long-term ecological investigation is practiced, with the main objectives of monitoring and storing relevant data in ecology, establishing links among institutions and researchers and promote the exchange of data and knowledge. This organized network of LTER sites first appeared in the United States of America in the 1980s. In 1993 an international network was developed (ILTER) and, more recently, the European network of LTER sites was created. In 2011 the European network includes 22 countries represented through the corresponding national LTER networks. The LTER sites can be accessed through networks with different levels of integration: ILTER (the International LTER network), LTER-Europe (the European LTER network) and LTER US (United States LTER network).
Long Term Research Platforms - PORBIOTA offers access to four Long Term Ecological Research Sites integrated into European and International LTER networks. At each site researchers can develop ecosystem research, monitoring and experimentation, using the available facilities, equipment and sensors, human resources and datasets.
LTER-PT Sites are: