Ocean acidification is the process in which the pH of the world’s oceans decreases due to the production of atmospheric CO2. The increase of CO2 and decrease in pH leads to changes in calcification, growth, and abundance of species such as coral reefs, mussels, seagrass, and macroalgae. Habitats experience the indirect effects of such CO2 increases. They must remain resistant to sudden changes in pH and CO2 in order to benefit the organisms they support. By modeling the effects of lowering pH in habitats with corals, mussels, seagrass, and microalgae, we can determine the costs to these species. Coral reefs and mussels are calcifying organisms that are negatively affected by the pH which limits survival and stunts, or even stops, growth and development. Lower pH decreases the species complexity of corals and mussels and ultimately the species richness in habitats. Mytilus mussels, for example, require specific pH to function. The species of mussels, other than Mytilus, that survive decreases in pH lack “structural complexity” to support dense surrounding vegetation. Therefore, the loss of Mytilus mussels due to ocean acidification allows for a more stable yet less diverse habitat. Continue reading →
As a lover of wildlife and birds, Franzen begins his article by questioning the effects of climate change on birds. Many reputable sources deem that bird biodiversity and populations will be endangered by climate change, however Franzen argues that birds are capable of adapting. In fact, argues that North American birds may become even more diverse due to climate change. Needless to say, Franzen is not convinced of the immediate threat to birds that global warming presents. In this article, he explores climate change in relation to democracy, Peru, and Costa Rica. Continue reading →
Biodiversity within an ecosystem has mutualistic and symbiotic relationships within that environment. The results of deforestation can be dramatic to these relationships, especially in cases with frugivores. The relationships between frugivores and fallen fruit are what help disperse seeds across the forest floor, which also helps the process of germination. In this study, Bieber et al. (2014) analyzed the mutualistic interactions between ants and fallen fruit in São Paulo State, SE Brazil. The scientists were examining the difference in interactions between disturbed and undisturbed forests. They compared the richness of ants at each fruit, species density per station, frequency of specific ant groups, frequency of fruit and pulp removal, and distance of fruit removal. The study was conducted using four disturbed forests, and four undisturbed forest areas. In these areas, there were thirty sampling stations with synthetic fruit placed 10 m apart from each other to ensure independent discoveries. The fruit were placed on a white sheet of paper within a wire cage to ensure that vertebrates did not access the fruit at each sampling station. Continue reading →
In South East Queensland, Australia Pavlacky et al.(2014) conducted a study on the vulnerability of birds, rainforest ecosystems, and the biological impacts in response to deforestation in local and regional areas. The central idea is the to investigate the life history and forest structure to rank the vulnerability of avian species, while also looking at species loss along different kinds of forest structure and landscape change. The objectives are evaluating the effects of life history traits on the patch occupancy and vulnerability of rainforest birds, determining the relative effects of stand, landscape, and patch structure on species richness, and evaluating the relative contributions of deforestation and fragmentation to species richness. Continue reading →
There has been recent controversy over the state of many pristine rain forests. Those that have previously been called “virgin” due to the absence of human interaction are now being reviewed. It seems that humans have inhabited forests such the Amazon Basin, the lowland Congo basin, and the Indo-Malay region of Southeast Asia for many years. Evidence of human presence in these virgin forests includes pottery fragments, charcoal soil lairs, and iron tools. Because of this, there is little doubt of the presence of human civilizations in these lands. The question becomes: how has their presence affected the forests ability to prevail. These natives have used slash and burn techniques to create agriculture space, which has been largely thought of as the most harmful deforestation methods in recent times. It seems that the presence of humans on these lands about 2,500 years ago has actually enhanced the soil fertility due to this burning method. Human intervention and management of the land may have also caused an increase in tree diversity. Continue reading →
Island biodiversity is of paramount importance on a global scale. The islands of the world contain twenty percent of all terrestrial plant and animal species. In addition the rate of endemic species on islands is much greater than on main lands, and island species are facing many threats. Over half of the most recent extinctions on the planet come from species inhabiting islands. In addition one third of all terrestrial species that are currently threatened with extinction are island-dwelling species (Couchamp et al. 2014). Continue reading →
Our newest book, published on May 6, 2015 and available at Amazon.com for $19.95.
The focus of this book is the interactions between energy, ecology, and climate change, as well as a few of the responses of humanity to these interactions. It is not a textbook, but a series of chapters discussing subtopics in which the authors were interested and wished to write about. The basic material is cutting-edge science; technical journal articles published within the last year, selected for their relevance and interest. Each author selected eight or so technical papers representing his or her view of the most interesting current research in the field, and wrote summaries of them in a journalistic style that is free of scientific jargon and understandable by lay readers. This is the sort of science writing that you might encounter in the New York Times, but concentrated in a way intended to give as broad an overview of the chapter topics as possible. None of this research will appear in textbooks for a few years, so there are not many ways that readers without access to a university library can get access to this information.
This book is intended be browsed—choose a chapter topic you like and read the individual sections in any order; each is intended to be largely stand-alone. Reading all of them will give you considerable insight into what climate scientists concerned with energy, ecology, and human effects are up to, and the challenges they face in understanding one of the most disruptive—if not very rapid—event in human history; anthropogenic climate change. The Table of Contents follows: Continue reading →
Surveying 85 unique sites on the western borders of North Carolina and Virginia, biologist Nicholas Caruso and his team collected data on adult specimens of Appalachian woodland salamanders (genus Plethodon). The results showed a reduction in salamander body size in accordance with lower climate temperatures. Because woodland salamanders are lungless they breathe through their skin and require a moist environment for survival. The authors used historical and present-day data to model the changes in body size of 15 species of salamanders over the past 55 years. The dataset included 9,450 adult body size measurements from 102 populations of the 15 different species of salamanders. An 8% reduction in the average salamander size was found in all of the species over the 55-year study (Caruso et al, 2014). The reduction in body size reveals the plasticity of organisms to adapt to changes in climate. Because body size is directly linked to diet and foraging behavior, growth rates are also affected. Smaller body size means less surface area, and less loss of moisture through cutaneous responses. Also, the salamanders that were surveyed have demonstrated an increase in metabolism. Continue reading →
Invasive species, especially plant species, are one of the greatest current threats to the Earth’s biodiversity. It is feared that with the advent of global warming areas favorable to such species will increase, especially for those invasives from warmer climates that have naturalized near areas of marginal temperature. This could have negative impacts on the diversity of exposed populations, so species distribution models (SDMs) have been developed to estimate possible future distributions of organisms. These models make predictions by relating occurrence data to environmental conditions, giving a general idea of how the potential threat of an invasive species may change over time, and suggesting possible mitigation activities. Such models however have rarely been tested against experiments from the field. Sheppard et al. (2014) seek to validate SDMs through field trials at varying sites based on suitability as predicted by SDMs. If the predicted success of species in the models matches those of actual field trials, then we could be more confident in ability of models to assess the risk of invasive success. The experiment also addresses the validity of the enemy release hypothesis, which is often assumed to be the case in invasive studies. The hypothesis posits that invasive species leave behind any natural enemies when they are introduced to a new environment, which would contribute to their success. This experiment questions that assumption and its use in SDMs. Continue reading →
The United States Endangered Species Act (ESA) is responsible for the protection of species and their habitats. The ESA maintains a list of the species at risk; the ultimate goal is to get these species off of the list. In order to get an endangered species removed (delisted) the ESA must regard that species as self-sustaining. The definition of a self-sustaining species becomes difficult as the ESA looks at conservation-reliant species. A conservation-reliant species is defined as a species that has been delisted; however it requires management in order to prevent it from once again being at risk. Continue reading →