Brenda B. Lin

Resilience in Agriculture through Crop Diversification: Adaptive Management for Environmental Change

Recognition that climate change could have negative consequences for agricultural production has generated a desire to build resilience into agricultural systems. One rational and cost-effective method may be the implementation of increased agricultural crop diversification. Crop diversification can improve resilience in a variety of ways: by engendering a greater ability to suppress pest outbreaks and dampen pathogen transmission, which may worsen under future climate scenarios, as well as by buffering crop production from the effects of greater climate variability and extreme events. Such benefits point toward the obvious value of adopting crop diversification to improve resilience, yet adoption has been slow. Economic incentives encouraging production of a select few crops, the push for biotechnology strategies, and the belief that monocultures are more productive than diversified systems have been hindrances in promoting this strategy. However, crop diversification can be implemented in a variety of forms and at a variety of scales, allowing farmers to choose a strategy that both increases resilience and provides economic benefits.

Synergies between Agricultural Intensification and Climate Change Could Create Surprising Vulnerabilities for Crops

ABSTRACT An inevitable consequence of global climate change is that altered patterns of temperature and precipitation threaten agriculture in many tropical regions, requiring strategies of human adaptation. Moreover, the process of management intensification in agriculture has increased and may exacerbate vulnerability to climate extremes. Although many solutions have been presented, the role of simple agroecological and agroforestry management has been largely ignored. Some recent literature has shown how sustainable management may improve agroecological resistance to extreme climate events. We comment specifically on a prevalent form of agriculture throughout Latin America, the coffee agroforestry system. Results from the coffee literature have shown that shade management in coffee systems may mitigate the effects of extreme temperature and precipitation, thereby reducing the ecological and economic vulnerability of many rural farmers. We conclude that more traditional forms of agriculture can offer greater potential for adapting to changing conditions than do current intensive systems.

Maximizing the Environmental Benefits of Carbon Farming through Ecosystem Service Delivery

The international carbon market provides a unique opportunity to increase ecosystem services and biodiversity through the revegetation of agricultural landscapes. Although the primary motivation for revegetation is to increase carbon sequestration, revegetated areas can provide additional financial, social, and environmental cobenefits that provide different levels of private and public net benefit. Conversely, carbon farming, if it is not implemented carefully, can create disbenefits, such as increased land clearing, monoculture plantations replacing diverse remnants, and unintended impacts across national borders. Economic models of carbon revegetation show that policies aimed at maximizing carbon sequestration alone will not necessarily lead to high uptake or maximize cobenefits. Careful consideration of policy incentives that encourage carbon plantings to deliver both public and private cobenefits is required, and solutions will need to balance both objectives in order to incentivize the sustainable, long-term management of carbon plantings across the landscape.

Mangrove filtration of anthropogenic nutrients in the Rio Coco Solo, Panama

Measurements of the distribution pattern of several nutrients (ammonia, nitrite, nitrate, and phosphate) and indicators (dissolved oxygen and conductivity) were conducted along the river Coco Solo on the Caribbean coast of Panama. The project investigated the extent to which mangrove forests could act as a vegetative buffer zone between disturbed freshwater sources and coastal water. Upriver freshwater samples were collected in known areas of human disturbance to assess levels of the nutrients near points of origin and exhibited elevated concentrations of nutrients. Samples were taken along the mangrove estuary to study the concentrations of nutrients as they moved through the estuary into the ocean. Expected and observed values were compared to see whether concentration levels of the chemicals exhibited normal dilution patterns. Graphs show that the nutrient levels at the estuary points are significantly lower than expected through normal dilution, indicating the removal of nutrients through another mang...

Coffee (Café arabica var. Bourbon) fruit growth and development under varying shade levels in the Soconusco region of Chiapas, Mexico.

The belief that less shade cover will increase coffee production has encouraged farmers to reduce or eliminate shade trees from coffee agroforestry systems. However, this reduction in shade may alter environmental factors within coffee systems that may adversely affect fruit production in low-input systems. This will be especially detrimental in light of current climate change patterns in Southern Mexico. In this study, coffee fruit growth, fruit drop, and fruit weight were examined under two different levels of shade cover (highu2009=u200960%u2009to 80%u2009and mediumu2009=u200930%u2009to 50%) in low-input coffee farms of Chiapas, Mexico. Coffee berries were counted and measured throughout the 2005 growing season and weighed at harvest. Results showed that solar radiation, temperature, humidity, and soil moisture were correlated with fruit growth, all of which are environmental factors heavily controlled by shade cover. Fruit drop was highly correlated to both wind and soil moisture. Fruit weights were also highly correlated to soil moisture, but not significantly different between sites. Yield extrapolations calculated from site data showed little difference between the two sites, indicating that the high-shade site produced equally well to the medium-shade site. Future management for coffee agriculture should address the use of shade to maintain beneficial environmental factors for coffee production, since more highly shaded coffee systems are able to maintain productive environmental factors and high production rates.