Desktop classification of inland wetlands for systematic conservation planning in data‐scarce countries: mapping wetland ecosystem types,disturbance indices and threatened species associations at country‐wide scale

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A new, multi-scaled graph visualization approach: an example within the playa wetland network of the Great Plains

We employed a sliding-window approach at multiple scales (window sizes and dispersal distances) to calculate seven standard graph-theoretical metrics within a subset of a large, freshwater wetland network. In contrast to most graph analyses, which quantify connectivity at a single (global) scale or at a patch-level scale, a multi-scaled, sliding-window approach provides an assessment that bridges these two approaches to examine patch clusters. As a case study we focused on a subset of a habitat patch network in a ~20,000 km² area encompassing 2,782 playa wetlands in the panhandle of Texas. Playas are seasonal wetlands of the southern Great Plains of North America that form a network of regional habitat resources for wildlife. The large size of this network meant that global metrics failed to capture localized properties, so we used contour mapping to visualize continuous surfaces as functions of playa density, linkage density, and other topological traits at different window sizes and dispersal distances. This technique revealed spatial patterns in the components (i.e., the network properties of regions of the landscape at a given dispersal scale), with the spatial scale of habitat clustering varying with the size of the sliding window and dispersal distance. Using a tool familiar to landscape ecology (sliding-window methodology) in a novel way (to examine ecological networks at multiple scales), our approach provides a way to represent ecologically determined local-scale graph properties and illustrates how a multi-scaled approach is useful in examining habitat connectivity to investigate graph properties.     

Seed germination of seven pepper cultivars at constant or alternating high temperatures

Summary

Seeds of seven pepper (Capsicum annuum L.) cultivars (Anaheim TMR 23, California Wonder 300, Coronado, Jalapeno M, Ma Belle, Mercury, and Yolo Wonder B) were germinated at constant day and night temperatures of 25,30,35 and 40°C or at alternating temperatures of 40/25,40/30 and 40/35°C for 14 days. Germination percentages and rates were similar at 25 and 30°C. Largest differences in cultivar responses occurred at 35°C where germination percentages ranged from 24 to 96%, and rates, calculated as summation of the number of seeds germinated on a given day divided by day number, varied from 3 to 26 (theoretical maximum value of 100). At 40°C, germination percentages were less than 5% and rates were less than one for all cultivars. Cultivars with the most heat tolerance were ‘Mercury’ and ‘Yolo Wonder B’. At alternating temperatures, germination percentages and rates were higher than those at constant 40°C. The increases were greatest when the temperature was lowered by 15°C (40/25°C) and least when temperatures were lowered by 5°C (40/35°C). Tetrazolium tests showed that a large percentage of the ungerminated seed was still viable from the highest temperature. At lower temperatures, fewer ungerminated seeds were viable with no viable ungerminated seeds from the lowest temperature.     

Effects of Brans from Specialty Sorghum Varieties on In Vitro Starch Digestibility of Soft and Hard Sorghum Endosperm Porridges

Brans of specialty sorghum varieties (high tannin, black, and black with tannin) were used to investigate the effects of sorghum phenolic compounds on starch digestibility of soft and hard sorghum endosperm porridges. Endosperms of varieties with the highest and lowest grain hardness index were mixed with brans of specialty sorghum varieties in the ratio of 85:15 and cooked into porridges with distilled water using a Rapid Visco Analyzer. Brans of condensed tannin containing sorghum varieties (high‐tannin and black with tannin sorghums) significantly (P < 0.05) decreased starch digestibility and estimated glycemic index (EGI) and increased resistant starch (RS) content of endosperm porridges. However, the addition of phenolic‐rich tannin‐free (mostly anthocyanins) black sorghum bran significantly (P < 0.05) increased starch digestibility and EGI but did not affect RS content of endosperm porridges. The disparate effects with black bran may, in part, result from its larger particle size and different bran structure compared with other sorghum varieties evaluated. Thus, our study showed that not only presence of phenolic compounds in the brans but also structural differences of specialty sorghum brans can have significant effects on starch digestibility.     

Winter Composting Using the Passively Aerated Windrow System

Field trials demonstrated that agricultural wastes could be successfully composted in the winter with the passively aerated windrow system. Three small windrows were constructed. One pile contained a sheep manure-straw mixture, while the other two piles contained varied amounts of horse manure, cow manure, and bedding materials (straw, wood chips). The piles were constructed on a porous base of wood chips. Standard four-inch (10 cm) perforated pipes were placed approximately three feet apart in the porous base, perpendicular to the length of the windrow. Piles were covered with 15 to 20 centimeters of finished compost. A commercial compost covering fabric permeable to gases and water vapor but impermeable to liquid water was used for additional insulation and protection against high winds. Ambient temperatures ranged from ?27°C to 15°C during the trials. Initially, all three piles froze. Then the ends of the piles began to heat up, with the southern ends which received the most sunlight heating up first. Plugging the pipes seemed to help the piles heat up faster, but did not appear to be necessary. Thermophilic temperatures were attained and the composting cycle took 50 to 80 days after the piles heated up. Oxygen levels were highest at the bottom of the pile, and decreased as one moved to the top of the pile. The biggest practical problem encountered was the snow drifts that periodically formed at the windrow base, covering the pipe openings.     

Effect of buckwheat (Fagopyrum esculentum) on soil‐phosphorus availability and organic acids

As a cover crop, buckwheat (Fagopyrum esculentum) may increase soil‐P availability. Buckwheat was grown in low‐P and P‐fertilized field plots, and organic anions were measured in rhizosphere soil. Soil‐P availability was not affected by buckwheat, but the concentration of rhizosphere tartrate^2– was significantly higher (p < 0.005) in low‐P vs. P‐fertilized plots. This suggests that organic‐anion root exudation may have a role in buckwheat‐rhizosphere P dynamics.     

Investigation of Yacon Leaves (Smallanthus sonchifolius) for α-Glucosidase Inhibitors Using Metabolomics and In Silico Approach

Yacon (Smallanthus sonchifolius (Poepp.) H. Robinson) leaves is traditionally consumed as herbal tea in many countries including Indonesia. This plant’s antidiabetic properties have been extensively researched, but studies on the responsible active compound identification are scarce. Information on the active compounds is critical for the consistency of Yacon herbal tea quality. The aim of this study was to identify α-glucosidase inhibitors in Indonesian Yacon leaves grown in two different locations using FTIR- and LC–MS/MS-based metabolomics in combination with in silico technique. Yacon leaves ethanol (50 and 95%) and water extracts were tested for α-glucosidase inhibitory activity, with the 95% ethanol extract being the most active. Geographical origins were found to have no major impact on the activity. In parallel, chemical profile of Yacon leaves extract was determined using FTIR and LC–MS/MS. Orthogonal Projection to Latent Structure (OPLS) was used to analyze both sets of data. OPLS analysis of FTIR data showed that compounds associated to α-glucosidase inhibitor activity included those with functional groups –OH, stretched CH, carbonyl, and alkene. It was consistent with the result of OPLS analysis of LC–MS/MS data, which revealed that based on their VIP and Y-related coefficient value, nystose, 1-kestose, luteolin-3′-7-di-O-glucoside, and 1,3-O-dicaffeoilquinic acid isomers, strongly linked to Yacon’s α-glucosidase inhibitor activity. In silico study supported these findings, revealing that the four compounds were potent α-glucosidase inhibitors with docking score in the range of ? 100.216 to ? 115.657 kcal/mol, which are similar to acarbose (? 115.774 kcal/mol) as a reference drug.

Graphical abstract

     

Fertilizer management impacts on stand establishment, disease, and yield of Irish potato

Summary Excessive fertilizer application in North Carolina, USA results in high residual soil levels of P, K and total soluble salts in potato fields. Our objectives were to determine the salt sensitivity of three common cultivars (Atlantic. Snowden and Superior), and the effects of planting density and fertilization on stand establishment, soilborne disease, and yield. Greenhouse results suggest that potato growth and emergence, but not shoot initation, are reduced by high salinity. On a Portsmouth fine sandy loam, high fertilizer rates did not reduce stands of cv. Atlantic in the field in 1996 or 1997. Excess N resulted in moreRhizoctonia stem canker in 1996, and lower yields at the lower planting density in 1997. Yield compensation for reduced plant density occurred in 1997 at the lower N rates (56 and 112 kg N ha⁻¹) and at the high PK rate (49 kg P and 139 kg K ha⁻¹).