James H. Kennedy

Integrating Ecology and Environmental Ethics: Earth Stewardship in the Southern End of the Americas

The South American temperate and sub-Antarctic forests cover the longest latitudinal range in the Southern Hemisphere and include the worlds southernmost forests. However, until now, this unique biome has been absent from global ecosystem research and monitoring networks. Moreover, the latitudinal range of between 40 degrees (°) south (S) and 60° S constitutes a conspicuous gap in the International Long-Term Ecological Research (ILTER) and other international networks. We first identify 10 globally salient attributes of biological and cultural diversity in southwestern South America. We then present the nascent Chilean Long-Term Socio-Ecological Research (LTSER) network, which will incorporate a new biome into ILTER. Finally, we introduce the field environmental philosophy methodology, developed by the Chilean LTSER network to integrate ecological sciences and environmental ethics into graduate education and biocultural conservation. This approach broadens the prevailing economic spectrum of social dimensions considered by LTSER programs and helps foster bioculturally diverse forms of Earth stewardship.

Conformation to Bergmann's Rule in White-tailed Deer can be Explained by Food Availability

Abstract The body size of white-tailed deer (Odocoileus virginianus) increases with latitude and thus exhibits the pattern predicted by Bergmanns rule on the basis of surface to volume ratios and heat loss. This pattern is more simply explained by the distribution of food available per individual animal, which is driven by two factors, the net primary production (NPP) of plants and deer population density. Food availability is often overlooked as a cause of an increase in body size in large terrestrial herbivores in temperate latitudes because of a fundamental misconception about the global distribution of plant productivity. Within a small latitudinal range, white-tailed deer body size as evidenced by modern deer and Holocene paleozoological remains is inversely related to population density and directly related to food availability. Food availability per animal is a product of plant productivity and population density, and is correlated with both local and regional body size variability. These local and regional food-body size patterns are consistent with recent analyses of global NPP datasets which show that ecologically relevant NPP is highest in the north temperate latitudes where white-tailed deer attain their largest body size.

Comparison of Chironomids and Other Macroinvertebrates Associated with Myriophyllum spicatum and Heteranthera dubia

ABSTRACT Macroinvertebrate communities inhabiting exotic Eurasian milfoil (Myriophyllum spicatum L.) and native water stargrass (Heteranthera dubia (Jacq.) MacM.) macrophytes were studied from March 1999 to June 2000 in experimental ponds constructed to simulate reservoir wetlands. Although macrophyte architecture explained some variation in macroinvertebrate abundance between the two macrophytes, most variation was explained by the sampling months. Total number of macroinvertebrates was positively correlated with epiphyton biomass, and epiphyton biomass was significantly different between the two plant species and among sampling months. Taxa richness did not vary between the two plant types. Chironomid larvae were the most abundant organisms and were dominated by Apedilum elachistum on both plant species. Annual production of five chironomid species was estimated by the size-frequency method. Apedilum elachistum exhibited the highest productivity- 9.9 g dry wt m−2 y−1 of plant surface area on M spicatum and 8.5 g dry wt m−2 y−1 on H. dubia.

A paleozoological perspective on unionid (Mollusca: Unionidae) zoogeography in the upper Trinity River basin, Texas

In north central Texas, USA, the zoogeography of unionids in the Trinity River is thought to consist of upland and lowland biogeographic components reflective of differences in upstream and downstream hydraulic conditions. Historical and modern surveys from a limited number of localities were used to delineate these zoogeographic provinces based on the absence of several species thought to occur only in the lower Trinity River drainage. Available zooarchaeological data indicate that at least one species considered absent from the upper Trinity River basin was present during the late Holocene (roughly the last 2500 years), suggesting that both biogeographical provinces shared similar mussel fauna in the recent geological past. The discrepancy between historical and zooarchaeological data is probably the result of inadequate sampling and of an extirpation gradient related to impoundments that have been constructed in this drainage during the last century. The presence of lower Trinity species during the late Holocene in the upper Trinity drainage challenges interpretations drawn from modern biogeographic studies.

The Terminal Pleistocene Extinctions in North America, Hypermorphic Evolution, and the Dynamic Equilibrium Model

Abstract The cause of megafaunal extinctions at the end of the last glaciation has been hotly debated during the last few decades, most recently at the global scale. In North America and elsewhere the debate centers on whether or not human hunters, who seemingly first entered the continent during the extinction period, caused the extinctions through over-hunting. An alternative explanation is that climate change during the terminal Pleistocene radically modified existing habitats and this caused the extinctions. Hustons (1979, 1994) dynamic equilibrium model (DEM) of community species richness provides a theoretical context for explanations of the extinctions in North America and highlights life history characteristics of extinct mammals. These life history traits and associated phenotypes are a seldom-explored line of evidence concerning the causes of the extinctions. In light of life history traits, environmental disturbance is implicated as the proximate cause of the extinctions, but the DEM does not preclude overkill as a contributing cause in North America.

A Minimally Invasive Technique to Monitor Valve-Movement Behavior in Bivalves

A real time, minimally invasive method to observe valve movement of bivalves using proximity sensors and a personal computer has been developed. The method is being evaluated as a tool to assess both episodic toxicity events and ambient toxicity. The method described minimizes contact with the animal to the anchoring of one valve and the placement of a small aluminum foil disk on the other valve, and allows the measurement of the distance that a clams valves are open. Using proximity sensors and an aluminum foil target, valve movements of the Asiatic clam, Corbicula fluminea were measured and digitally recorded using a data acquisition board and a personal computer. One advantage of this method is its use of readily available stock electronics. In its final form, we envision an in situ biological monitoring system using C. fluminea deployed in aquatic systems in association with automated physical/chemical monitoring systems like those found at USGS gauging stations. A tool such as this could be used as ...

Macroinvertebrate assemblages of submerged woody debris in the Elm Fork of the Trinity River, Texas

ABSTRACT We studied the taxonomic composition and spatial and temporal variability of macroinvertebrates inhabiting coarse woody debris in an 8 km segment of the Elm Fork, a low gradient prairie river in Texas. Seventy-seven macroinvertebrate taxa were collected from submerged wood habitats compared with 38 taxa collected from soft benthic substrata. Assemblages were highly variable spatially and temporally, particularly among seasons. An ordination of species and environmental variables indicated some trends in the longitudinal distribution of flow-dependent species but overall did not find coarse woody debris-inhabiting taxa to have strong associations with many of the selected environmental variables. Significant seasonal differences occurred in the abundances of the Chironomidae (Diptera) with Orthocladiini dominating in the winter and Chironomini and Tanytarsini in the summer and autumn. Data gathered after an extended high flow period in the spring indicated a greater resilience of snag habitats than benthic substrata, with rapid re-colonization of coarse woody debris by macroinvertebrates following the high flow episodes.

Relationships between benthic macroinvertebrate community structure and geospatial habitat, in-stream water chemistry, and surfactants in the effluent-dominated Trinity River, Texas, USA.

Over the past 20 years, benthic macroinvertebrate community structure studies have been conducted on the upper Trinity River, Texas, USA, which is dominated by municipal wastewater treatment plant (WWTP) and industrial effluents. The Trinity River is located in the Dallas-Fort Worth metropolitan area, and is the most highly populated and industrialized watershed in Texas. As such, the Trinity River represents a near-worst-case scenario to examine the environmental effects of domestic-municipal and industrial effluents on aquatic life. A 1987 to 1988 study concluded that many stretches of the river supported a diverse benthic community structure; however, a decline in taxa richness occurred immediately downstream of WWTPs. A 2005 study designed to parallel the 1987 to 1988 efforts evaluated how changes in water quality, habitat, and increased urbanization impacted benthic community structure. Physicochemical measurements, habitat quality, geospatial variables, and benthic macroinvertebrates were collected from 10 sites. Surfactants were measured and toxic units (TUs) were calculated for surface water and pore water as indicators of domestic/household use of cleaning products. Total TUs indicated a low potential for biological impacts. Toxic unit distribution was not dependent on WWTP location and did not correlate with any benthic variable. Eight environmental parameters were determined to be useful for predicting changes in benthic macroinvertebrate community structure: surfactant surface water TUs (SWTU), in-stream habitat cover, and surface water total organic carbon were the top three parameters. Abundance, taxa richness, and taxa similarity in 2005 had increased since the earlier study throughout the immediate vicinity of the metropolitan area.

Life History and Secondary Production of Caenis latipennis (Ephemeroptera: Caenidae) in Honey Creek, Oklahoma

Abstract The life history and production of Caenis latipennis Banks (Ephemeroptera: Caenidae) is described from Honey Creek, Oklahoma. Emergence behavior, fecundity, voltinism, and secondary production were analyzed. C. latipennis had an extended emergence with five peaks. Females emerged, molted, mated, and oviposited in an estimated 37 min. Mean fecundity was 888.4 ± 291.9 eggs per individual (range, 239–1,576). Adult female head capsule widths in spring were significantly larger than in summer and fall. Compared with the other seasons, fecundity was significantly higher in early summer when densities were lowest. C. latipennis exhibited a multivoltine life cycle with five overlapping generations. Estimated annual secondary production for C. latipennis in Honey Creek was 4,404.28 mg/m2/yr, mean standing stock biomass was 274.64 mg/m2/yr, cohort production:biomass ratio was 5.79, and the annual production/biomass rate was 16.04/yr/yr. Standing stock biomass ranged from 7.6 to 705.4 mg/m2 during the year. Standing stock biomass did not vary significantly among seasons.

Filosofía ambiental de campo y conservación biocultural en el Parque Etnobotánico Omora: Aproximaciones metodológicas para ampliar los modos de integrar el componente social ("S") en Sitios de Estudios Socio-Ecológicos a Largo Plazo (SESELP)

This article discusses field environmental philosophy and biocultural conservation methods at the Omora Ethnobotanical Park in the Cape Horn Biosphere Reserve in Chile.