Plants in constructed wetlands help to treat agricultural processing wastewater

Over the past three decades, wineries in the western United States and sugarcane processing for ethanol in Central and South America have experienced problems related to the treatment and disposal of process wastewater. Both winery and sugarcane (molasses) wastewaters are characterized by large organic loadings that change seasonally and are detrimental to aquatic life. We examined the role of plants for treating these wastewaters in constructed wetlands. In the greenhouse, subsurface-flow flumes with volcanic rock substrates and plants steadily removed approximately 80% of organic-loading oxygen demand from sugarcane process wastewater after about 3 weeks of plant growth; unplanted flumes removed about 30% less. In field studies at two operational wineries, we evaluated the performance of similar-sized, paired, subsurface constructed wetlands with and without plants; while both removed most of the oxygen demand, removal rates in the planted system were slightly greater and significantly different from those of the unplanted system under field conditions

Evaluating dairy waste management systems ̓influence on fecal coliform concentration in runoff

This paper examines the environmental factors influencing the die-off and transport of fecal coliform bacteria present in wastes applied to the land surface. These factors are examined specifically for dairy waste management systems and the net effect each system has on runoff water quality. A model is developed that considers the effects of precipitation, season, method of wastes storage and application, die-off of the bacteria in storage, die-off of the bacteria on the land surface, infiltration of bacteria into the soil profile, soil characteristics, overland transport of bacteria (runoff), and buffer zones. The model is then applied to the Tillamook basin in northwestern Oregon to evaluate which waste management procedures significantly decrease bacterial pollution potential in agricultural runoff

Numerical modeling of diazinon transport through inter-row vegetative filter strips

Abstract A numerical simulation model of pesticide runoff through vegetative filer strips (PRVFS) was developed as a tool for investigating the effects of pesticide transport mechanisms on VFS design in dormant-sprayed orchard. The PRVFS model was developed applying existing theories such as kinematic wave theory and mixing zone theory for pesticide transport in the bare soil area. For VFS area, the model performs flow routing by simple mass accounting in sequential segments and the pesticide mass balance by considering pesticide washoff and adsorption processes on the leaf, vegetative litter, root zone and soil. Model sensitivity analysis indicated that pesticide transfer from surface soil to overland flow and pesticide washoff from the VFS were important mechanisms affecting diazinon transport. The VFS cover ratio and rainfall intensity can be important design parameters for controlling diazinon runoff using inter-row VFS in orchard. The PRVFS model was validated using micro-ecosystem simulation of diazinon transport for 0, 50 and 100% VFS cover conditions. The PRVFS model is shown to be a beneficial tool for evaluating and analyzing possible best management practices for controlling offsite runoff of dormant-sprayed diazinon in orchards during the rainy season.

Converting oak woodland or savanna to vineyards may stress groundwater supply in summer

Water resources are important to land-use planning, especially in regions where converting native oak woodlands or savannas to wine grape vineyards may affect the amount of water available for restoring salmon runs. Research has shown that woodland conversion to grasslands (for possible rangeland grazing) leads to greater and more sustained stream flow and groundwater recharge; however, little information is available about woodland conversion to vineyards. To inform resource managers and planners, we developed a water balance model for soil and applied it to vineyards, native oak woodlands and annual grasslands to evaluate their relative use of groundwater. We applied the model to Sonoma County, using climate data from 1999 to 2011, and determined that oak tree canopy coverage of 40% to 60% results in annual groundwater extraction equivalent to that of an established irrigated vineyard. However, vineyard groundwater use far exceeded that of oak woodlands in late summer to early fall, which could further stress already affected groundwater resources. We also evaluated the prediction sensitivity of the model to key parameters associated with rain levels, soil water-holding capacity and irrigation management

Chloride levels increase after 13 years of recycled water use in the Salinas Valley

The use of recycled water for agriculture is a long-term water strategy in California. A study in the 1980s in Monterey County showed recycled water increased soil salinity but not to a level unacceptable for agriculture. Most growers in the northern Salinas Valley have been using it since 1998, and yet providers of the water and many growers are concerned that the sustained use of recycled water might cause deterioration of the soil. An ongoing study, initiated in 2000, compares the changes in soil salinity between a field receiving only well water and eight fields that receive recycled water. In 13 years of data, the average soil salinity parameters at each site were highly correlated with the average water quality values of the recycled water. Soil salinity did increase, though not deleteriously. Of most concern was the accumulation of chloride at four of the sites, to levels above the critical threshold values for chloride-sensitive crops

A phylogenetic taxonomy of the Cyrtodactylus peguensis group (Reptilia: Squamata: Gekkonidae) with descriptions of two new species from Myanmar

A phylogenetic taxonomy of species in the Cyrtodactylus peguensis group from the Ayeyarwady Basin of Myanmar is constructed based on color pattern, morphology, and molecular systematic analyses using the mitochondrial gene NADH dehydrogenase subunit 2. Newly collected samples from the type locality of C. peguensis and other localities indicate that this clade is endemic to central Myanmar and contains at least seven species, four of which are undescribed. Three species, including C. peguensis occur in the low hills of the Bago Yoma Range within the central portion of the Ayeyarwady Basin. Two of these, C. myintkyawthurai sp. nov. from the northern and central Bago Yoma and C. meersi sp. nov. which is syntopic with C. peguensis in the southern Bago Yoma are described herein. As more lowland hilly areas bordering, and within the Ayeyarwady Basin are surveyed, more new species of this group are likely to be discovered. These discoveries continue the recent surge of descriptions of new species of Cyrtodactylus that are being discovered in Myanmar

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Standards vary in studies using rainfall simulators to evaluate erosion

Rainfall simulators are often employed to measure erosion rates, in order to estimate stream loading of sediment and nutrients in California foothill watersheds. The rainfall simulator enables the precise application of artificial rain with controlled drop sizes, intensity and duration. In addition to rain factors such as drop energy and intensity, several soil- and cover-related factors affect erosion rates. While computational models have evolved to quantify erosion based on field measurements taken by rainfall simulators, there has not been a consensus on the methodology to be deployed, especially in forested and remote landscapes. In addition, it is challenging to apply study results from small plots to entire watersheds. To guide future fieldwork on sediment loading to water bodies, we review key concerns related to rainfall simulator studies