Ecomorphological Variation in Three Species of Cybotoid Anoles

© 2018 by The Herpetologists' League, Inc. Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species that mirror differences across the ecomorphs. Among these species of cybotoids, those that have longer limbs tend to move less frequently, occupy broader perches, and have smaller fourth toes with fewer lamellae. We also observed that the species with greater male-biased size dimorphism had larger heads, smaller dewlaps, and smaller testes. These results are consistent with the predictions of sexual selection theory, in that species with large male body size may have larger heads because of increased male-male combat, and smaller testes potentially attributable to a trade-off between pre- and postcopulatory selection. Overall, our study suggests that a combination of local adaptation to different structural habitats and sexual selection might produce ecomorphological diversification within cybotoid anoles of the same ecomorph group

A regional analysis of excess capacity in China's power systems

China's economy has entered a “new normal,” characterized by slower economic growth and widespread overcapacity in its industrial sectors. Nevertheless, construction of power plants, especially coal-fired plants, continues at a rapid pace. Our analysis examines the extent of overcapacity in China's regional electricity grids. We show that already in 2014, the average reserve margin across China's regional grids was roughly 28%, almost twice as high as a standard planning reserve margin in the U.S. In addition, we find large variations in reserve margins across regional power grids in China, with the highest reserve margin (64%) in the Northeastern grid. This paper examines future reserve margins across regions in China under three growth scenarios. The results suggest that the majority of China will not need new baseload coal power (at least for reliability purposes) before 2020, and potentially not until 2025, under the low- and mid-growth scenarios. Under the high-growth scenario, China's central and eastern regions will need to import more power or built new capacity by 2020. As China's energy sector enters this new normal, our results highlight the growing importance of establishing mechanisms — planning processes and markets — that coordinate generation and transmission investments across grid regions, and that align the country's energy sector investments with its longer-term air quality and climate goals

Biofuels in China: an analysis of the opportunities and challenges of Jatropha Curcas in Southwest China

Over the past decade China has quietly emerged as the world’s third largest biofuel producer. Concerned over rising food prices, in June 2007 China’s central government banned the use of grain-based feedstocks for biofuel production and reoriented the country’s bioenergy plans toward perennial crops grown on marginal land. One such crop, Jatropha curcas, has emerged as a high potential biodiesel feedstock because of its adaptability to the diverse growing conditions where China’s marginal land is abundant. Provincial governments in Southwest China, for instance, have drafted ambitious plans to increase Jatropha by over one million hectares in the next decade. This paper analyzes the opportunities and challenges for the development of a Jatropha industry in Southwest China. Given the scarcity of data on Jatropha productivity and economics, we argue that plans to rapidly expand Jatropha acreage and refining capacity could jeopardize the industry’s longer-term viability. Alternatively, a commitment to silvicultural, engineering, and economic research could set the industry on a more sustainable path

Evidence for multiple paternity in two species of Orconectes crayfish

Multiple mating is expected to be common in organisms that produce large clutches as a mechanism by which sexual reproduction can enrich genetic variation. For freshwater crayfish, observation of multiple mating suggests the potential for high rates of multiple paternity, but genetic confirmation is largely lacking from natural populations. We studied paternity within wild-caught broods of two crayfish species in the genus Orconectes (Sanborn\u27s crayfish ( Orconectes sanbornii (Faxon, 1884)) and the Allegheny crayfish ( Orconectes obscurus (Hagen, 1870))). Although females have been observed mating with multiple males, this is the first genetic confirmation of multiple paternity in broods of these two species. Berried females were collected in the field and maintained in aquaria until their eggs hatched. We amplified and genotyped extracted DNA from maternal and hatchling tissue for several microsatellite loci. For both species, paternity reconstruction (GERUD 2.0) yielded 2-3 sires per brood and no single paternity clutches. We discuss these results from natural populations in light of the body of work on reproductive ecology of decapod crustaceans and in the context of changes in life history following the transition from marine to freshwater habitats

Data from: Does adaptive radiation of a host lineage promote ecological diversity of its bacterial communities? A test using gut microbiota of Anolis lizards

Adaptive radiations provide unique opportunities to test whether and how recent ecological and evolutionary diversification of host species structures the composition of entire bacterial communities. We used 16S rRNA gene sequencing of faecal samples to test for differences in the gut microbiota of six species of Puerto Rican Anolis lizards characterized by the evolution of distinct ‘ecomorphs’ related to differences in habitat use. We found substantial variation in the composition of the microbiota within each species and ecomorph (trunk-crown, trunk-ground, grass-bush), but no differences in bacterial alpha diversity among species or ecomorphs. Beta diversity analyses revealed subtle but significant differences in bacterial composition related to host phylogeny and species, but these differences were not consistently associated with Anolis ecomorph. Comparison of a trunk-ground species from this clade (A. cristatellus) with a distantly related member of the same ecomorph class (A. sagrei) where the two species have been introduced and are now sympatric in Florida revealed pronounced differences in the alpha diversity and beta diversity of their microbiota despite their ecological similarity. Comparisons of these populations with allopatric conspecifics also revealed geographic differences in bacterial alpha diversity and beta diversity within each species. Finally, we observed high intraindividual variation over time and strong effects of a simplified laboratory diet on the microbiota of A. sagrei. Collectively, our results indicate that bacterial communities are only weakly shaped by the diversification of their lizard hosts due to the strikingly high levels of bacterial diversity and variation observed within Anolis species

Economic and carbon emission impacts of electricity market transition in China: A case study of Guangdong Province

China's electricity system is the world's largest, in terms of installed generating capacity, and is also the world's largest single source of greenhouse gas emissions. In 2015, China embarked on reforms in its electricity sector that aim to introduce market mechanisms in wholesale pricing. This study provides a quantitative assessment of the economic and carbon dioxide (CO ) emission impacts of transitioning to electricity markets in China, focusing on Guangdong Province. We find that market reforms deliver significant annual cost savings (21 to 63 billion yuan, 9%–27% reduction in total costs in a base case) to consumers in Guangdong, with smaller production cost savings (12 billion yuan, 13% reduction in production costs in a base case). Savings for consumers are accompanied by a large reduction in net revenues for coal and natural gas generators, raising concerns about generator solvency, longer-term resource adequacy, and the need for transition mechanisms. Market reforms increase CO emissions in Guangdong, as a result of gas-to-coal switching, though higher hydropower imports from neighboring provinces could offset these emissions. CO pricing has a limited impact on CO emissions in the short run and has the potential to lead to significant wealth transfers. The most important benefit of market reforms will be in providing an economic framework for longer-term operations and investment. 2 2 2

Large or small? Rethinking China s forest bioenergy policies

China s forest bioenergy policies are evolving against the backdrop of pressing national energy challenges similar to those faced by OECD countries, and chronic rural energy challenges more characteristic of developing countries. Modern forest bioenergy could contribute to solutions to both of these challenges. However, because of limitations in current technologies and institutions, significant policy and resource commitments would be required to make breakthroughs in either commercializing forest bioenergy or modernizing rural energy systems in China. Given the potential attention, funding, and resource trade-offs between these two goals, we provide an argument for why the focus of China s forest bioenergy policy should initially be on addressing rural energy challenges. The paper concludes with a discussion on strategies for laying the groundwork for a modern, biomass-based energy infrastructure in rural China

Incentives for carbon sequestration and energy production in low productivity collective forests in Southwest China

This paper develops three scenarios for the management of an existing, low productivity, collective forest plot in Southwest China: continuation of the status quo, transition to sustainable forest management (SFM), and conversion to a short rotation species for producing biomass for electricity generation. We examine how economic incentives vary across the three scenarios and how payments for CO2 sequestration and offsets affect incentives. We find that SFM is risky for forest managers and is highly sensitive to revenues from initial thinning; that carbon revenues can lower some of the risks and improve the economics of SFM; but that carbon revenues are effective in incentivizing management changes only if yield response to thinning is moderately high. Energy production from stem wood is too low value to compete with timber, even with revenues from CO2 offsets. However, conversion of existing forests into short rotation species for timber rather than energy is more profitable than any scenario considered here, highlighting the need for regulatory innovations to balance incentives for timber production with conservation goals. The results underscore the importance of improved public sector regulatory, planning, extension, and analysis capacity, as an enabling force for effective climate policies in China s forestry sector