Comprehensive characterization of an aspen (<i>Populus tremuloides</i>) leaf litter sample that maintained ice nucleation activity for 48 years

Decaying vegetation was determined to be a potentially important source of atmospheric ice nucleation particles (INPs) in the early 1970s. The bacterium Pseudomonas syringae was the first microorganism with ice nucleation activity (INA) isolated from decaying leaf litter in 1974. However, the ice nucleation characteristics of P. syringae are not compatible with the characteristics of leaf litter-derived INPs since the latter were found to be sub-micron in size, while INA of P. syringae depends on much larger intact bacterial cells. Here we determined the cumulative ice nucleation spectrum and microbial community composition of the historic leaf litter sample 70-S-14 collected in 1970 that conserved INA for 48 years. The majority of the leaf litter-derived INPs were confirmed to be sub-micron in size and to be sensitive to boiling. Culture-independent microbial community analysis only identified Pseudomonas as potential INA. Culture-dependent analysis identified one P. syringae isolate, two isolates of the bacterial species Pantoea ananatis, and one fungal isolate of Mortierella alpina as having INA among 1170 bacterial colonies and 277 fungal isolates, respectively. Both Pa. ananatis and M. alpina are organisms that produce heat-sensitive sub-micron INPs. They are thus both likely sources of the INPs present in sample 70-S-14 and may represent important terrestrial sources of atmospheric INPs, a conclusion that is in line with other recent results obtained in regard to INPs from soil, precipitation, and the atmosphere.

Comprehensive characterization of an Aspen (<i>Populus tremuloides</i>) leaf litter sample that maintained ice nucleation activity for 48 years

Decaying vegetation was determined to be a potentially important source of atmospheric ice nucleation particles (INPs) in the early 1970s. The bacterium Pseudomonas syringae was the first microorganism with ice nucleation activity (INA) isolated from decaying leaf litter in 1974. However, the ice nucleation characteristics of P. syringae are not compatible with the characteristics of leaf litter-derived INPs since the latter were found to be sub-micron in size while INA of P. syringae depends on much larger intact bacterial cells. Here we determined the cumulative ice nucleation spectrum and microbial community composition of the historic leaf litter sample 70-S-14 collected in 1970 that conserved INA for 48 years. The majority of the leaf litter-derived INPs were confirmed to be sub-micron in size and to be sensitive to boiling. Culture-independent microbial community analysis only identified Pseudomonas as potential INA. Culture-dependent analysis identified one P. syringae isolate, two isolates of the bacterial species Pantoea ananatis, and one fungal isolate of Mortierella alpina as having INA among 1170 bacterial colonies and 277 fungal isolates, respectively. Both, Pa. ananatis and M. alpina, are organisms that produce heat-sensitive sub-micron INPs. They are thus both likely sources of the INPs present in sample 70-S-14 and may represent important terrestrial sources of atmospheric INPs, a conclusion that is in line with other recent results obtained in regard to INPs from soil, precipitation, and the atmosphere.

Effect of wood shaving litter density on the growth, leg disorders and manurial value in broiler

The study was conducted with an aim to investigate the effect of litter density on growth, leg health and litter quality of broiler chickens from d1-42 days. Day-old male broiler chicks (n=400; Cobb 500) were distributed randomly into four litter densities [T1, T2, T3 and T4] treatments, each treatment had 5 replicates with 20 birds per replicate cage in a completely randomized design. Wood shaving was used as litter materials to a thickness of 5 cm, 8 cm, 11 cm and 14 cm on the floor of the pen. Birds were reared on the litter floor open-sided housing condition with ad libitum feed and water throughout the trail period. Data on feed intake (FI), body weight (BW), feed conversion ratio (FCR) and mortality were measured weekly. Litter sample was collected on day 42 to assess the nitrogen content (N2 %), dry matter (DM%) and moisture level (%). Footpad dermatitis (FPD) and hock burn (HB) incidences were measured on day 42 to assess the leg quality of birds. Results demonstrated that litter thickness had no significant (P>0.05) effect on FI, BW, FCR and mortality of broilers from d1-42 days. The N2, DM or moisture levels (%) of litter were also unaffected (P>0.05) between treatment. Leg disorders such as HB and FPD were influenced (P<0.01) by treatment. The incidences of HB and FPD were higher (P<0.01) in T1 and T2 than other treatments. It can be inferred from our current study that, leg health may be deteriorated by using low density wood shaving without affecting growth and litter quality of broiler chickens. Bang. J. Anim. Sci. 2018. 47 (1): 21-27

Analysis of the heat and smoke release rate of selected undergrowth types

The paper presents the results of tests conducted regarding the flammability and heat release rate (HRR) of selected forest leaf litter under the impact of assumed flux density taking place in fire conditions. Litter samples for testing needs were collected from places characterised by similar biotope parameters. They were collected from 4 types of tree stands: from a cluster of pine trees, beech trees, spruce trees and oak trees. The highest HRRmax values were obtained during the testing of the spruce litter sample at a thermal exposure of 50 kW/m2. This suggests, that as compared to the remaining litter types being tested, this litter released the greatest amount of heat in the given time unit and has an evident impact on the rate and magnitude of a forest fire and in an indirect way on the ignition of subsequent leaf litter in adjacent forest zones.

Leaf litter copepods from a cloud forest mountain top in Honduras (Copepoda: Cyclopidae, Canthocamptidae)

Five different species of Copepoda were extracted from a leaf litter sample collected on the top (at 2000 m a.s.l.) of a cloud forested mountain in El Cusuco National Park, Honduras. Three of them, one Cyclopidae and two Canthocamptidae are new to science, and are described herein. Olmeccyclops hondo sp. nov. is the second representative thus far known of this New World genus. Moraria catracha sp. nov. and Moraria cusuca sp. nov. are the first formally described members of the genus occurring in Central America. The concept of a “Moraria-group” is considered to be an artificial grouping and is limited here to the genera Moraria and Morariopsis only. The distributional range of this group is essentially Holarctic, with the mountainous regions inHonduras, and probably in westNicaragua, as the southernmost limits in theNew World.

A new species of Tyrannomyrmex (Hymenoptera: Formicidae: Myrmicinae) from India

A second species in the myrmicine ant genus Tyrannomyrmex Fernández, 2003, T. dux sp. n., based on a solitary worker from a leaf litter sample from Kerala state, southern India, is described. The original genus definition is slightly modified to include the description of this new species.

Príspevok k topografickému výskumu malakofauny okresu Levice [Contribution to the topographic malacological survey in the Levice District, SW Slovakia]

The paper brings new information on mollusc distribution of Levice District in southern part of Central Slovakia. The data were obtained from 14 localities, which lie mainly in the vicinity of the Ipeľ River and southern slopes of Štiavnické vrchy Mts. Together 78 mollusc species (50 land species and 28 fresh-water species) were found. From 9 localities a litter sample from 1m² was analyzed for quantitative evaluation of snail assemblages. Malacocoenoses of thermophilous forest mollusc species were determined in the area of Štiavnické vrchy Mts. foothill (localities 2, 7, 8). The species Limacus flavus, Euconulus praticola, Pisidium amnicum and Unio crassus albensis are important from the viewpoint of nature conservation and geographical distribution. Carpathian species Bythinella austriaca, Vestia turgida, Bielzia coerulans and also European forest species Merdigera obscura reach the southern boundary of their natural area of occurrence. Typical for this region are malacocoenoses of xeric biotopes, composed from species of 4–6 ecoelement – Cecilioides acicula, Cepaea vindobonensis, Granaria frumentum, Chondrula tridens, Xerolenta obvia, Truncatellina cylindrica, Cochlicopa lubricella and Monacha cartusiana. High diversity was observed by freshwater malacocoenoses. Anodonta anatina attenuata, A. cygnea solearis, Unio tumidus zelebori, Radix ampla are typical for stagnant water biotopes (abandoned ‘paleopotamon’ side arms). In slow flowing waters of the Ipeľ River beside the common species also rare species like Anisus septemgyratus and Pisidium amnicum were detected. Interesting is also the occurrence of strong population of invasive species of Asian mussel Sinanodonta woodiana, which is known to infiltrate into a number of streams all around Slovakia.

Dinemasporium lanatum anam.- sp.nov. from Cuba

A new species of Dinemasporium, occurring on decaying leaves of an undetermined tree in a leaf litter sample, is reported from Cuba.

Measurement of bacterial and fungal contributions to respiration of selected agricultural and forest soils

A technique using selective inhibitors was used to estimate the relative contributions of bacterial and fungal populations to the respiration of six soils and one litter sample. The ratios of bacterial to fungal respiration in the four agricultural soils, given in percentage of the total microbial activity, ranged from 10/90 to 35/65, with the average ratio being about 30/70. In the forest soils, the ratios were 20/80 and 30/70, and in a beech litter sample, the ratio was 40/60. The fungi clearly dominated in all samples. The ratios were not found to be pH related. The difficulties which had previously limited the use of selective inhibitors for in situ soil ecological investigations, such as insufficient inhibitor specificity, inhibitor inactivation or degradation, and errors of measurement caused by elimination of competitor populations, were either resolved or methodologically avoided in the experiments. Inhibitor selectivity was demonstrated using both mixed and pure cultures of microorganisms from each soil. Through the use of experiments with short incubation periods (6–8 h), problems with population shifts and inhibitor degradation were eliminated.

Collecting a Poultry Litter Sample for Analysis

Through research, tables have been developed that describe the average nutrient concentration of animal wastes. However, the actual nutrient concentration of manures may vary from one livestock operation to another. Factors that contribute to this variation include: composition of the feed ration, design of the waste management system, season of year, animal health, etc. Therefore, it is important that livestock wastes are sampled and analyzed to determine their nutrient concentrations before a sound, nutrient management plan can be designed, implemented, or maintained. This document is HS938, one of a series of Department of Horticultural Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. November 2003. https://edis.ifas.ufl.edu/hs189