315
Ecological processes and material flows can be measured by ecotrons with noninvasive methods, while at the same time, the environmental conditions are controlled and regulated. Ecosystems that are investigated by ecotrons are thus closed
systems. There is no undesired input or outflow of water, nutrients, resources,
organisms, or gases, or input from undesired disturbance variables or stress factors.
All changes taking place in such ecosystem processes are documented and can be
compared with one another and with different scenarios in a standardized manner.
In ecotrons, biodiversity is manipulated at different trophic levels at the same time.
In this manner, the responses of different species and genotypes and species to
stress, disturbances, or resource limitations and their effects on ecosystem functions
can be examined. This approach enables a much better recording and understanding
of aboveground and belowground interactions between different plant and animal
species, microorganisms, and abiotic factors, as well as material and energy flows.
The integration of close-range RS sensors in ecotrons is still very new and in need
of further development if we are to understand the complete system of soilvegetation- climate-biotic interactions with spectral response.
13.2.1.4 WSNs, Sensorboxes
WSNs can be used to record complex vegetation processes both extensively and
continually in a noninvasive, cost-effective, and automated manner (Hart and
Martinez 2006).
The implementation of wireless mobile and stationary sensor networks in terrestrial environmental systems (Fig. 13.2g, h) enables high-frequency in-situ information to be recorded using various sensor types (e.g., thermal, multispectral,
hyperspectral, soil moisture, air condition). Another advantage of mobile wireless
ad hoc sensor networks is their self-organizing infrastructure, leading to significant
reduction of cost and time consumption for installation, maintenance, and operation.
WSNs are being implemented more frequently in environmental and vegetation
monitoring (Hwang et al. 2010; Mollenhauer et al. 2016) in agriculture and the food
industry (Mafuta et al. 2013; Ruiz-Garcia et al. 2009), for monitoring terrestrial and
underground conditions such as soils, and for aquatic applications (Yick et al. 2008).
They have also been used for experimental platforms such as greenhouses or the
GCEF (Mollenhauer et al. 2016). In the context of vegetation health, WSNs are
implemented to detect and verify forest fires in real time (Liyang Yu et al. 2005;
Lloret et al. 2009) or to demonstrate the effects of the 2015 El Niño extreme drought
on the sap flow of trees in eastern Amazonia (Mauro et al. 2016).
WSNs have also been used to record how important processes of soil-plantatmosphere interactions; vegetation processes such as transpiration, carbon uptake
and storage, and water stripping from clouds are affected by climatic variation and
the temporal and spatial structure of the vegetation interior in whole ecosystems
(Oliveira et al. 2016). Teodoro et al. (2016) used WSN to demonstrate the interplay
between hydraulic traits, growth performance, and stomata regulation capacity in
three shrub species in a tropical montane scrubland of Brazil under contrasting
13 A Range of Earth Observation Techniques for Assessing Plant Diversity
Ecological processes and material flows can be measured by ecotrons with noninvasive methods, while at the same time, the environmental conditions are controlled and regulated. Ecosystems that are investigated by ecotrons are thus closed
systems. There is no undesired input or outflow of water, nutrients, resources,
organisms, or gases, or input from undesired disturbance variables or stress factors.
All changes taking place in such ecosystem processes are documented and can be
compared with one another and with different scenarios in a standardized manner.
In ecotrons, biodiversity is manipulated at different trophic levels at the same time.
In this manner, the responses of different species and genotypes and species to
stress, disturbances, or resource limitations and their effects on ecosystem functions
can be examined. This approach enables a much better recording and understanding
of aboveground and belowground interactions between different plant and animal
species, microorganisms, and abiotic factors, as well as material and energy flows.
The integration of close-range RS sensors in ecotrons is still very new and in need
of further development if we are to understand the complete system of soilvegetation- climate-biotic interactions with spectral response.
13.2.1.4 WSNs, Sensorboxes
WSNs can be used to record complex vegetation processes both extensively and
continually in a noninvasive, cost-effective, and automated manner (Hart and
Martinez 2006).
The implementation of wireless mobile and stationary sensor networks in terrestrial environmental systems (Fig. 13.2g, h) enables high-frequency in-situ information to be recorded using various sensor types (e.g., thermal, multispectral,
hyperspectral, soil moisture, air condition). Another advantage of mobile wireless
ad hoc sensor networks is their self-organizing infrastructure, leading to significant
reduction of cost and time consumption for installation, maintenance, and operation.
WSNs are being implemented more frequently in environmental and vegetation
monitoring (Hwang et al. 2010; Mollenhauer et al. 2016) in agriculture and the food
industry (Mafuta et al. 2013; Ruiz-Garcia et al. 2009), for monitoring terrestrial and
underground conditions such as soils, and for aquatic applications (Yick et al. 2008).
They have also been used for experimental platforms such as greenhouses or the
GCEF (Mollenhauer et al. 2016). In the context of vegetation health, WSNs are
implemented to detect and verify forest fires in real time (Liyang Yu et al. 2005;
Lloret et al. 2009) or to demonstrate the effects of the 2015 El Niño extreme drought
on the sap flow of trees in eastern Amazonia (Mauro et al. 2016).
WSNs have also been used to record how important processes of soil-plantatmosphere interactions; vegetation processes such as transpiration, carbon uptake
and storage, and water stripping from clouds are affected by climatic variation and
the temporal and spatial structure of the vegetation interior in whole ecosystems
(Oliveira et al. 2016). Teodoro et al. (2016) used WSN to demonstrate the interplay
between hydraulic traits, growth performance, and stomata regulation capacity in
three shrub species in a tropical montane scrubland of Brazil under contrasting
13 A Range of Earth Observation Techniques for Assessing Plant Diversity