Leaf organic d13C and d18O values support this observation, because P. piscipula showed consistently higher d13C values than G. floribundum , coupled with lower d18O indicating that the decrease in photosynthetic carbon isotope discrimination was associated with greater stomatal conductance and greater photosynthesis . Greater photosynthesis in P. piscipula is consistent with maintaining a canopy of leaves later into the dry season. Thus, our results are most consistent with maintenance plant water potential to maximize carbon gain during the onset of the dry season. The observation that P. piscipula appeared to use shallower water sources and maintained its canopy of leaves later into the dry season was not expected. Part of this pattern is driven by the capability of P. piscipula to utilize dynamic sources of water, such as the cold front precipitation during the frontal season . This makes sense, because the Laja bedrock layer was a poor source of water at all times, and soil pockets, which are available, but heterogeneous in distribution, were always better sources of water than rock layers . Water content of soil/ bedrock sources changed along the year suggesting a different seasonal contribution to plant water uptake. The hg of topsoil in the wet and frontal seasons were very similar and three times greater than values measured in the dry season. The Sascab bedrock layer could be a significant source of water in the wet and frontal seasons, but not in the dry season.
Soil pockets had two times more water than topsoil in the dry season suggesting that they could be an important source of water for trees during the dry season. In the dry season,vertical farms the rock profile had hg between 1 and 5 % but nearly all were less than 1 %. These values were slightly lower than those reported by Querejeta et al. and Hasselquist et al. in nearby areas, which suggest that the bedrock was subjected to a greater evaporation during this study. The d18O values of water in this study integrated processes ranging from evaporation of soil and bedrock water sources, transpiration of tree species, and precipitation events. In the wet season, enriched values of d18O of water in topsoil 10–15 cm and trees revealed the occurrence of a depleted precipitation event that occurred on October 21, 1 day before sampling, bringing 19.7 mm of water . Furthermore, a frontal system including cold front #3, the tropical wave #37, as well as the remnants of tropical storm Kiko that formed in the pacific, converged on the study area days before the wet season sampling in October 2007 . Hurricanes, tropical storms and cold fronts generally have lower stable isotope ratios than convective precipitation events . For example, Perry et al. recorded d18O values of 9.91 % for precipitation during tropical storm Mitch in 1998, and precipitation events ranging from 6 to 10 % for d18O have been recorded in the vicinities of the study area . Consequently, depleted oxygen values in soil 15–30 cm and P. piscipula and G. floribundum trees could be accredited to precipitation originated from these events. Soil pockets also showed more negative values than rock, suggesting that depleted rain water reached this layer.
During dry season measurements in February 2008, the d18O of topsoil 0–15 cm was more positive than groundwater suggesting another depleted source of water. Cold front #29, which occurred 4 days before sampling and brought 33.9 mm , could be the main source of water. However, the more negative value of topsoil from 0 to 5 cm could be affected by dew water since this soil sampling was done early in the morning. More negative d18O values in topsoil than ground water have also been observed by Saha et al. in similar environmental conditions in Miami, associated with water condensation occurring at night in the upper soil layers. Condensation has been shown to deplete d18O soil water 10–15 cm depth by 5 % . Condensation can also account for up to 47 % of total transpiration . Surface dew is easily generated when temperatures go below the dew point at night or in early morning . Under tropical conditions in Tahiti, Clus et al. reported average dew yields of 0.102 mm of dew during the dry season. Therefore, condensed water could be an important source for P. piscipula. Overall, our results indicate that variation in phenology between these two deciduous tropical dry forest tree species, which vary in the timing of their deciduousness, is not akin to the relatively large variation in rooting depth that can occur between tropical evergreen and deciduous species , but rather reflects the diversity of plant physiological strategies that occur in tropical forest .The excremental body has been defined by Mark Feather stone as the disposable body that is set up within US society as a foil to the formalized, white, utopian American body in order to assert the US’s global power through corporeal poetics.Furthermore, the excremental body has been demonized as a way to justify the disembodied, mechanized body of supermodernity which represents the perfect, post human body which does not break down, feel pain, or expire.
Ultimately, the excremental body is the pathologized other that feels pain and ultimately represents “the horrific real of the vulnerable body.”In regards to the US’s involvement in Vietnam during the Cold War Era, American society was, and still is, culturally and psychologically unwilling to recognize and empathize with the suffering and tortured bodies in the Global South and within its own borders. The pathologization of the “natural” body, soil, water, urine, and all that is “other” allows US society to relentlessly exercise and grow its accursed share through neo colonial agendas.As the devastating effects of the Anthropocene become ever more acute, contemporary artists Jun Nguyen Hatsushiba and Jae Rhim Lee re present the excremental body at the forefront of their respective projects in order to remediate disembodiment,vertical plant growing highlight the interdependency of all life forms, and hold the US necropolitics accountable for countless ecological atrocities. The “Anthropocene” popularized in 2000 by the atmospheric chemist Paul Crutzen and ecologist Eugene Stoermer, has been deemed by geologists to begin in the 1950s due to the dramatic effects of modern and nuclear weapons upon ecosystems during WW2 and the Cold War battles fought between communism and capitalism.The Anthropocene critically links human actions with the rapid change and depletion of earth’s systems, but its history actually begins long before the 1950s. When German biologist, Ernst Haeckel, coined the term “ecology” in 1866, it became a discipline that facilitated the domination of colonial anthropocentrism over passive, human and nonhuman worlds — effectively becoming what T.J. Demos calls the “science of empire.”A lot has changed for the worse since 1866, since ecology’s colonial origins still persist through turbo capitalism’s apathy towards the biosphere exacerbates a psychological and cultural fear of morbidity due to a “uniquely modern form of egoism [which] has broken [the] interdependence between the living and the dead. With disastrous results for the living, who now think of the dead as eliminated.”This perversion of death is further clarified by Achille Mbembe’s theory of Necropolitics as “let live and make die” which is in direct response to Michel Foucault’s concept of biopolitics defined as “live and let die.” Coined by Foucault in the 1970’s during the Cold War era, biopolitics meant to “make live and let die” in line with the capitalist liberal governmentality that specifically sought to make life “cozy” for the First World nation states.On the other hand, necropolitics delineates a management of life in the neo liberal capitalist world: let all those who hold wealth and power live, and make the rest die through systematic abandonment.
The Vietnam War is particularly relevant to the artists Jun Nguyen Hatsushiba and Jae Rhim Lee since their projects relate to the necropolitics of US chemical warfare that sparked the formation of an ecological consciousness in American society. In these works, the contaminated human and environmental “body” collide.Staged in South Korea and later shown to a Japanese audience, Jun Nguyen Hatsushiba’s film, Memorial Project Waterfield: The Story of the Stars , aims to commemorate the losses incurred by ecological, political, and economic violence during the American War in Vietnam . Focusing on the violent trauma incurred on the body, land, and water Nguyen Hatsushiba re presents the act of urinating as a way to memorialize the embodied struggles of Vietnamese people who suffer from slow ecological violence and US cultural hegemony. By creating a multidimensional space within his work, he offers a heterogeneous re presentation of Vietnamese society and suffering that has been systematically erased by hegemonic US narratives of the Vietnam War. On the other hand, Jae Rhim Lee’s Infinity Burial Project offers consumers an opportunity to remediate the imperceptible accumulation of industrial toxins within the human body through the use of mushroom mycelia in order to promote environmental stewardship and provoke the psychological structures surrounding cultural death denial . By uncovering the ubiquity of invisible chemical contamination in America and offering a green burial alternative that facilitates a physical transfer of nutrients from a decomposing human body to the soil, her work expands one’s understanding of how human death is linked to vibrant, nonhuman systems. In order to ease a people’s fear of death stoked by super modernity, her work attempts to bridge the dichotomy between “man” and “nature” with her focus on interspecies relationships within the soil. Both artists utilize alienated substances, such as dejecta and decomposing bodies, in order to probe colonial logics and animacy hierarchies that are socially and racially charged. Such matter labeled as “waste” is often steeped in logics of purity and danger that justifies necropolitical classifications of people as valuable or disposable. Residues of human life, ranging from excreta and corpses to industrial toxins and landmines, serve as important reminders of humans’ undeniable entanglement with ecological systems that lie beyond human control. Although these residues are out of sight, and often imperceptible, they are potent reminders of anthropocentric frameworks and heighten the agency and animacy of nonhuman “objects” or systems. In this paper I will show how both artists seek to halt the repetitious calamities caused by humans by transforming substances that are considered taboo –– urine and corpses –– into opportunities for ecological, psychological, and cultural remediation.In 2006, Jun Nguyen Hatsushiba staged Memorial Project Waterfield: The Story of the Stars as a performance installation at the 6th Gwangju Biennale in South Korea with the main intention of turning it into a video performance . The physical performance space was confined to a prison like structure constructed out of 8 meter tall walls that were lined with long metal poles . Visitors could only view the work from an aerial perspective provided by standing on the bridge that overlooks the courtyard and connects the Gwangju Biennale’s two gallery buildings. 26,000 plastic water bottles packed the entire ground surface of the 10 meter wide by 14 meter long space. During the live performances, there were 3 groups of 5 men and women who would alternate shifts every hour. Some performers came from Vietnam in order to assist the artist with training, while the rest of the cast consisted of Korean men and women volunteers aged 18 – 30 years old. These volunteers were cast based on their interest in contemporary art, youthful appearance, and overall good health.During shifts, the performers were tasked with drinking water, urinating into containers, injecting urine into recently emptied bottles, carefully wading through the bottles, and listening to the spontaneous orders of the shift leader to take cover, sit, or lie down .Over the span of about 20 days, these repetitive, carefully orchestrated tasks gradually formed 50 urine colored stars that were each 1 meter wide and constituted the image of the 50 stars on the American Flag hybridized with the yellow star of the Vietnamese flag . This symbolic relationship between the two flags’ stars reflects the entwined historical, cultural, and economic relationships between the US and Vietnam. Nguyen Hatsushiba attributes the chemical destruction of US and Vietnamese ecosystems to militarization and neo liberal capitalism.