Carbon sequestration in the rain forest: alternatives using environmentally friendly biotechnology

Abstract

ResumoCom o recente aumento na concentração atmosférica de CO e o conseqüente aumento nas médias de temperatura, as 2 alterações ambientais previstas poderiam causar danos à civilização na forma em que conhecemos. Como conseqüência desses previsões, a necessidade de seqüestrar carbono está se tornando urgente e uma das opções que temos é o uso do potencial que as florestas tropicais têm de assimilar CO através da fotossíntese. No entanto, se considerarmos o uso de 2 plantas para aumentar o seqüestro de carbono, haverá um problema que é o fato de muitas espécies vegetais aclimatarem, o que significa uma inibição na assimilação de CO pela produção de açúcares. No presente artigo, propomos que algumas 2 rotas bioquímicas poderiam ser alteradas em plantas de forma a controlar a fotossíntese, metabolismo de carboidratos e também a síntese de celulose. Com isso talvez se pudesse aumentar o seqüestro de carbono. Dentre as tecnologias disponíveis, aquela que apresenta um rápido desenvolvimento recente é o controle do metabolismo através de alterações no controle genético de vias metabólicas. Ainda que isto seja controverso, o tempo está correndo e de acordo com as previsões, nós podemos ter um pouco mais de 50 anos antes que a concentração de CO atmosférico dobre. Considerando 2 que já conhecemos alguns genes que poderiam ser alvo de transformações de plantas e que estas técnicas estão melhorando com grande velocidade, neste trabalho nós discutimos algumas das formas ambientalmente saudáveis para abordar o problema.http://www.biotaneotropica.org.br Date Received: March, 26, 2002 Accepted: April, 04, 2002 AbstractAs carbon dioxide increases on Earth atmosphere, the rise in average temperatures may provoke changes in the environment that could damage civilisation as we know it. As a result, the need to sequester carbon becomes urgent, and one of the options we have is to use the potential of the forests to do it by enhancing assimilation of CO through 2 photosynthesis. However, if we consider the use of plants to increase carbon sequestration, a problem that looms is that species often acclimate and actually reduce CO assimilation through feedback mechanisms of the sugars that are the 2 product. In the present article, we propose that some biochemical pathways, such as those in control of photosynthesis, carbohydrate metabolism and assimilation, and cellulose and polysaccharide synthesis, that might be targeted so that C sequestration, could be increased. Genetic control of metabolic pathways is now among the technologies available. Although genetic modification of native plants is controversial, according to the forecasts the concentration of atmospheric CO will double in just 50 years, and, therefore, we may have few options short of greatly reducing output. Fortunately, we 2 already know a few candidate genes to be targets for genetic manipulation, and in this short article we discuss some environmentally friendly approaches to the problem. Keywords

Carbon Sequestration: what really matters? - A reply to Buckeridge & Aidar

“…Of course, we are far from a robust theoretical construct and more research effort will be needed to accomplish this task, particularly in quantifying the relative effects of variability in spatial and temporal scales along gradients of environmental stresses on ecosystem properties related to productivity, decomposition, species diversity and biological interactions. As pointed out by Buckeridge & Aidar (2002), it may then be too late for sound conservation and management initiatives to be undertaken, but that should not discourage functional ecology studies nor be an excuse to premature manipulation at the molecular level.…”

“…The natural ecophysiological potential The second ecological flaw of Buckeridge & Aidar's (2002) is related to the fact that they have overlooked recent studies showing some relevant information regarding plant survival under adverse environmental conditions for different Brazilian vegetation types (Scarano & Franco 1998, Scarano et al 2001, de Mattos et al 2002, Scarano 2002. Plants from poor and stressful environments are able to survive by showing a constellation of attributes that may confer a great resistance to environmental stresses but negatively affect photosynthetic carbon assimilation (Chapin et al 1993).…”

“…One can think of ecological integration as operating at two major levels: (a) inward integration, where scientists succeed in integrating the different hierarchical levels of ecological science (molecules, cells, organs, organisms, populations, communities, landscape, biogeography); and (b) outward integration, where scientists succeed in integrating Ecology as a whole to non-biological sciences, more notably social and political sciences. Buckeridge & Aidar (2002) call our attention to global environmental change, a major ecological, social and political problem that requires solving. They appropriately highlight all the controversies surrounding global change theory, and develop their paper based on which is probably the most likely of two alternatives, i.e., that current rising of atmospheric CO and temperature is 2 man-induced and may bring disastrous consequences to life on Earth as we know it.…”

“…Buckeridge & Aidar (2002) state that 'our goal has to be to find ways to sequestrate carbon with higher efficiency', and that the use of genetically modified trees with enhanced capacity for carbon assimilation can help us achieve this goal. Even if we assume this goal as legitimate (see Socio-political flaws below), we see two major ecological flaws in their argument: (1) at present, with native plants as they are, there are no available models to explain or predict Brazilian ecosystem function in a changing environment, nor to predict the variation in magnitude of ecological processes along gradients of environmental stress; so genetic changes would come with a high level of unpredictability; (2) there are accounts of Brazilian species with a great intrinsic capacity for carbon assimilation, despite growing in resource-poor and stressful environments such as cerrados, restingas or rocky outcrops (Prado & Moraes 1997, de Mattos 1998; this can be seen as indication of an already great natural potential for carbon assimilation.…”

“…Even if we assume this goal as legitimate (see Socio-political flaws below), we see two major ecological flaws in their argument: (1) at present, with native plants as they are, there are no available models to explain or predict Brazilian ecosystem function in a changing environment, nor to predict the variation in magnitude of ecological processes along gradients of environmental stress; so genetic changes would come with a high level of unpredictability; (2) there are accounts of Brazilian species with a great intrinsic capacity for carbon assimilation, despite growing in resource-poor and stressful environments such as cerrados, restingas or rocky outcrops (Prado & Moraes 1997, de Mattos 1998; this can be seen as indication of an already great natural potential for carbon assimilation. Buckeridge & Aidar (2002) acknowledge the premature status, unpredictability and the dangers related to the application of their proposal and our aim in this section is to highlight, based on these two ecological flaws, some of the risks related to this type of practice.…”