1.  Research Objectives:

Understanding the relationship between ecological processes and environmental conditions requires parallel research in a variety of ecosystems and habitat types. With this goal in mind, the Terrestrial Sensing Group at the James Reserve is working to develop sensors network systems at other field stations. U.C. Berkeley's Gump South Pacific Research Station on Moorea, French Polynesia (http://moorea.berkeley.edu) provides a unique opportunity to expand sensing to a tropical ecosystem. This station routinely hosts a variety of researchers in the fields such as terrestrial ecology, marine biology, archeology, and oceanography. Given the opportunities for comparative research between temperate and tropical ecosystems, and a broad range of scientific research activities, the Gump Station is an ideal location for the deployment, testing and use of CENS sensor technology.  The Gump Station also recently became part of the Long Term Ecological Research Network (LTER: http://www.lternet.edu) focusing on coral reef health. This creates additional collaboration opportunities for future CENS marine sensor networks.

The Gump Station is currently collaborating with a local Tahitian non-profit organization, Te Pu 'Atiti'a (http://moorea.berkeley.edu/outreach/). Their three-part mission is to: document, preserve, and promote the biological and cultural heritage of Polynesia; build local scientific capacity for conservation and natural resource management; and combine modern science and traditional knowledge in a common pedagogic framework. The centerpiece of this joint venture is the Atitia Center, an ethnobotanical garden and cultural center currently under construction on the station property. The garden will one day host a wide range of Polynesian medicinal plants and food crops. It will also serve as an experimental research area for ethnobotanists, agronomists, anthropologists and other researchers.

The Terrestrial Group is currently working on two related projects at the Gump Station. The first involves the deployment of a sensor network within an area of the garden already planted with a variety of local food crops. Once a dense sensor network is installed, researchers will be able to use this ÒsmartÓ garden for studies in areas such as plant physiology, comparisons of traditional and modern agricultural techniques, cultivation of medicinal plant species, weed/pest control, and effects of invasive plant species on canopy light regimes. CENS technology infrastructure will also enable other terrestrial and marine researchers to start using sensor networks in their own studies.

The second project underway is an ethnobotanical study conducted by UCR graduate student, Sean Askay. This study is using microclimate and soil sensor arrays to evaluate the influence of weather conditions and the synodical lunar rhythm on the success of local sweet potato crops (Ipomea batatas), as predicted by traditional Tahitian agricultural and ecological knowledge.

2.  Approaches, Experiments and Systems:

Project 1: Garden sensor network:

Work on this project began in August of 2004 with the clearing of land for the Atitia Center garden and cultural center. Over the course of four weeks Sean Askay, CENS postdoc researcher Orlo Steele and several volunteers removed invasive plants species, prepared terraces, built rock walls, installed a timer controlled drip irrigation system, and setup two Onset Hobo Weather Stations.

Once the land was prepared some simple agricultural experiments were started. Several traditional crops species were planted in accordance and opposition to traditional lunar planting calendars. Crops planted included: four varieties of banana (Musa X paradisiaca L.), yams (Dioscorea alata), two varieties of taro (Colocasia esculenta), tarua (Xanthosoma sagittifolium), and two varieties of manioc (Manihota esculenta). The last three crops were planted at both the full and new moons, as a part of this pilot study. Some of these crops will be ready for harvest later this summer of 2005. At that time Sean Askay and Orlo Steele will continue work on the garden, planting addition medicinal plants and food crops.

At the moment, two Onset Hobo Weather Station data loggers are operating in the garden. Installed at the lower and upper boundaries of the planted area, these loggers have collected over 8 months of local weather data. Both the loggers are equipped with the following sensors: wind speed/direction, barometric pressure, Photosynthetically Active Radiation (PAR), temperature, relative humidity, and a single soil moisture probe at 50 cm depth. Once a fully functional ESS system is in place at the garden, it may be possible to automate irrigation through the use of real-time soil moisture data and electronically controlled water timers. At the moment simple programmable timers are in use to water the crops.

The Atitia Center site also features a partially completed, traditional open-air meetinghouse; in the future will also be home to a conference center and additional research facilities. Infrastructure currently under construction at the Gump Station will also provide high-speed and wireless Internet access to the garden, meeting the needs of CENS sensor technology.

Figure 25- Atitia Center's ethnobotanical garden (left to right):

1. Terrace building, drip irrigation system and planting crops - Sept. 2004

2. Garden in Mar. 2005 (clockwise: taro, bananas, manioc, and tarua)

3. Garden from above, banana trees, open-air meeting house (fare poteÕe) under construction

Project 2: Ethnobotany of Sweet Potato Agriculture and Lunar Planting Calendars:

Sean Askay's thesis project seeks to evaluate traditional Tahitian agricultural practices in relation to the success of local sweet potato crops (Ipomea batatas). Agricultural traditions throughout Polynesia regard the synodical lunar rhythm (the visible phases of the moon) as an important influence on crop growth and harvest quality. Numerous scientific studies have shown the effects of lunar cycles on plants, including: mitotic growth, water uptake, germination, and crop yield. Correlating differential crop success with lunar phases requires adjusting harvest yields for primary plant growth factors such as temperature, humidity, precipitation, and Photosynthetically Active Radiation (PAR). Background micro-climate and soil sensor data allows for the trend adjustments required to compare crops sequentially planted at different points of the lunar cycle, and subject to different environmental conditions.

With the assistance of Te Pu 'Atiti'a Director, Hinano Murphy, Sean Askay conducted interviews with Tahitian elders and farmers on on sweet potato cultivation during December 2004 and February 2005. Information on lunar planting calendars, practices and traditions were used to develop a controlled agricultural study.  A randomized complete block experimental design is being used to test 14 planting days throughout a complete lunar cycle of March 2005. With the assistance of Hinano Murphy and family, Sean Askay prepared a 12 by 14 meter experimental area and planted over 200 sweet potato vines donated by a local farmer.

Figure 26- Sweet Potato Experiment (left to right) ? March 2005

4.   Experimental plot area with chicken wire fence. Sweet potatoes planted in mounds

5.   Onset Hobo Weather Station: micro-climate and soil sensor array

6.   Young sweet potato vines two weeks after planting

7.   Hinano Murphy interviewing a local farmer in traditional sweet potato field

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At harvest time, during September of 2005, various measurements such as above vs. belowground plant biomass, and tuber yield, shape and quality will be collected. Once normalized for primary growth factors (using micro-climate and soil sensor data), we will look for yield trends corresponding to various lunar rhythms (synodical ? visible phases, tropical ? height of orbit in sky, and anomalistical ? distance to moon given elliptical orbit). With these results we hope find support for traditional Tahitian agricultural practices.

At the moment, we are using two Onset Hobo Weather Station data loggers to host a suite of weather and soil sensors. The first logger is recording wind speed and direction, barometric pressure, PAR, rainfall, temperature, and relative. The second logger hosts a small soil sensor array collecting soil moisture and temperature at 20 and 50 cm depths at three locations in the experimental plot. Preliminary soil sensor data collected during the first month of the study revealed differences in soil characteristic within the small experimental area. This soil sensor data, along with the blocked design of the experiments, will help to factor out effects that would have otherwise gone unnoticed.

Figure 27-  Soil moisture data for the sweet potato experiment site. There are three sensor sites with probes at 20 and 50 cm depth. They are named according to their relative position in the plot: Southwest, Northwest, and Eastern. Note: Soil at NW sensor location has greater water carrying capacity at both depths compared to the other locations. However, the E and NW sensors locations have opposite water carrying capacity at 20 vs. 50cm before the rain event. At the 20cm depth for E and NW, a rain event bring makes them approximately equal. However, at 50cm them maintain their original ranking after the rain event.

Figure 28 - Micro-climate Interactions for the sweet potato experiment site. Measurements for temperature and relative humidity at both 1.5m height and ground level, wind and gust speed, and PAR light values.
Note: During the daytime, temperatures at ground-level are higher than at 1.5m, whereas RH is roughly equal. However, at night, temperature is roughly equal at both measurements heights, but RH is higher at ground level. PAR, and therefore sunlight, predictably scale with temperatures during the day. However at approximately 3am there is a large drop in humidity and a rise in temperature. The higher winds/gusts observed at those times are likely the cause. Winds directions during this time (not depicted in the figure) were southerly, from deeper inside the bay. Perhaps breezes off the shallower (and possibly warmer) inner-bay waters are warmer than nighttime ocean breezes, possibility explaining the higher temperature.

3.  Problems Encountered:

Thus far the experiment has not experienced any major problems. Delays with broadband internet access to the island and in the construction of adequate computing facilities at the Gump, coupled with delays of a field-ready ESS system, has forced us to employ commercial data loggers. However, we hope all these issues to be resolved within the next several months.

4.  Major Accomplishments:

Preparation of an ethnobotanical research garden. Planting of several traditional crop plants as part of a pilot study on Tahitian agricultural knowledge. Installation of two weathers station which have already collected 8 months of micro-climate data ? August/September 2004

Commencement of a graduate student research project using sensor systems for testing the effects of lunar cycles and microclimate conditions on sweet potatoes, as suggested by traditional agricultural knowledge. Installation of a microclimate and soil sensor array for use in the experiment.

Sensor data-sharing collaborations: We have already had requests for our micro-climate data sets, as there is no other publicly-available weather data for our side of the island. Oceanographers from Scripps Institute interested in the effects of precipitation runoff on lagoon currents and a City and Regional Planning graduate student from UC Berkeley studying urban runoff are using rainfall data collected by our Hobo systems.

Discussions with biological researchers in the Tahitian government about potential collaboration opportunities: Government biologists would like to use sunlight/PAR sensor networks in several of their biological control experiments for invasive plant species. They are interested in contracting members of the Terrestrial group to install the sensor systems.

5.  Future goals and objectives:

We hope to have the use of a fully functional ENS system in place at the Gump Station in late 2005. This sensor system will supplement the existing commercial data loggers in use at the ethnobotanical garden and sweet potato project site. This entails the installation of database servers, wired/wireless connectivity and ESS hardware in the soon-to-be-completed laboratory building at the Gump Station.

In direct relevance to these two projects, we would like to continue agricultural and ecological research in regards to the traditional ecological knowledge of native Tahitians. Elders, farmers and fishers all have vast and intricate knowledge of the terrestrial and marine ecosystems of Tahiti. Continued work on these topics could not only lead to advancements in biology, ecology, anthropology and agriculture, but may also facilitate the cultural revival and renewed support of fast-disappearing traditional ecological knowledge.

The Gump Station hosts a wide range of researchers and students including marine biologists, oceanographers, urban planners and architects, archeologists and terrestrial ecologists. We also see great potential in expanding the use of sensor networks to many of these areas, offering new research tools to the diversity of current and future projects conducted there.

PEOPLE

M. Hamilton

N. Davies

S. Askay

O. Steele

H. Murphy and family