Effect of PTO-driven tillage machines on soil particles transfer

ArticleDisplacement of soil particles by erosion can be seen as a major threat to the quali ty of agricultural land in the conditions of Czech Republic. While the effects of water and wind erosion have long been investigated and reported, the effect of soil tillage technology on soil particles translocation are relatively new area of agriculture research. Soil tillage may contribute to the undesirable translocation of soil particles towards lower - lying parts of fields especially on slopes. The effect of soil tillage implements on soil particle translocation has not been sufficiently explained yet. The object of this research was to assess the influence of PTO (power takeoff) - driven tillage machines on soil particle translocation during secondary tillage (soil preparation). Measurements to determine the displacement of soil particles were performed in location Nesperská Lhota in the Central Bohemia Region. Measurements were performed on a sandy loam cambisol after harvest winter cereals (winter wheat). To indicate displacement of soil particles was used grit of white limestone (size 10 – 16 mm). Limest one was put down into the trench with known position orthogonal to the direction of working operations. Subsequently were performed working operations in the specified sequence. Limestone particles were counted and weighed in each section. It was detected by measuring the different nature of displacement for each machine. Statistical significance of differences in the weight of translocated particles was evaluated for different type of machines

THE FECUNDITY, TIME OF EGG DEVELOPMENT AND JUVENILE PRODUCTION IN SPINY-CHEEK CRAYFISH (ORCONECTES LIMOSUS) UNDER CONTROLLED CONDITIONS

We comprehensively describe the fecundity and time of embryonic development of the spiny-cheek crayfish (Orconectes limosus). Linear relationships between female size and ovarian fecundity, pleopodal fecundity, and production of juveniles at the 3rd stage, were confirmed. The ovarian fecundity was evaluated for the smallest as well as largest females in the sampled population (43-93 mm of body length); the number of oocytes (eggs) ranged widely, between 46 and 505. No significant difference was found between the ovarian and pleopodal fecundity observed just after egg laying. The value of the female gonadosomatic index just before laying was 4.2 ± 1.8% (0.8-7.7%). The mean diameter of eggs on female pleopods was 1.8 ± 0.2 mm (1.45-2.15 mm). A statistically significant difference was found between the numbers of eggs carried on individual pairs of pleopods. Mean time from laying to hatching was 46 ± 3.8 days (37-56 days), i.e. 647 ± 39.9 CTU (Celsius Temperature Units = degrees Celsius × days). Mean production of juveniles at the 3rd stage was found to be 135.7 ± 67.24 (15-243) juveniles. The early sexual maturation and also high number of juveniles at the 3rd stage per female gives this species a good predisposition for quick establishment in new localities

Surface water runoff of different tillage technologies for maize

ArticleThe present paper is focused on the evaluation of efficiency of soil-conservation technologies to reduce surface water runoff in Central Bohemia Region. In the last years, there has been an increase in maize planting on hillslope plots due to the construction of many biogas plants in conditions of Czech Republic. It enhances the risk of water erosion because the occurrence of sloping lands in the Czech Republic is high. To evaluate the technologies of stand establishment a field trial was laid out with four treatments of maize planting. The trial was laid out on a plot with light soil and slope of around 12%. It was a multi-year trial. To measure erosion parameters a rainfall simulator was used (measurement of surface runoff). The values obtained in two seasons show a positive effect of the soil surface cover by organic matter when reduced soil tillage was used. Soil loss also decreased at the same time compared to treatments with conventional soil tillage. It was found up to six-fold reduction in surface runoff by appropriate soil tillage technology during two seasons of measurement

Taming the terminological tempest in invasion science

Standardised terminology in science is important for clarity of interpretation and communication. In invasion science – a dynamic and rapidly evolving discipline – the proliferation of technical terminology has lacked a standardised framework for its development. The result is a convoluted and inconsistent usage of terminology, with various discrepancies in descriptions of damage and interventions. A standardised framework is therefore needed for a clear, universally applicable, and consistent terminology to promote more effective communication across researchers, stakeholders, and policymakers. Inconsistencies in terminology stem from the exponential increase in scientific publications on the patterns and processes of biological invasions authored by experts from various disciplines and countries since the 1990s, as well as publications by legislators and policymakers focusing on practical applications, regulations, and management of resources. Aligning and standardising terminology across stakeholders remains a challenge in invasion science. Here, we review and evaluate the multiple terms used in invasion science (e.g. ‘non-native’, ‘alien’, ‘invasive’ or ‘invader’, ‘exotic’, ‘non-indigenous’, ‘naturalised’, ‘pest’) to propose a more simplified and standardised terminology. The streamlined framework we propose and translate into 28 other languages is based on the terms (i) ‘non-native’, denoting species transported beyond their natural biogeographic range, (ii) ‘established non-native’, i.e. those non-native species that have established self-sustaining populations in their new location(s) in the wild, and (iii) ‘invasive non-native’ – populations of established non-native species that have recently spread or are spreading rapidly in their invaded range actively or passively with or without human mediation. We also highlight the importance of conceptualising ‘spread’ for classifying invasiveness and ‘impact’ for management. Finally, we propose a protocol for classifying populations based on (i) dispersal mechanism, (ii) species origin, (iii) population status, and (iv) impact. Collectively and without introducing new terminology, the framework that we present aims to facilitate effective communication and collaboration in invasion science and management of non-native species

Taming the terminological tempest in invasion science

Standardized terminology in science is important for clarity of interpretation and communication. In invasion science — a dynamic and quickly evolving discipline — the rapid proliferation of technical terminology has lacked a standardized framework for its language development. The result is a convoluted and inconsistent usage of terminology, with various discrepancies in descriptions of damages and interventions. A standardized framework is therefore needed for a clear, universally applicable, and consistent terminology to promote more effective communication across researchers, stakeholders, and policymakers. Inconsistencies in terminology stem from the exponential increase in scientific publications on the patterns and processes of biological invasions authored by experts from various disciplines and countries since the 1990s, as well as publications by legislators and policymakers focusing on practical applications, regulations, and management of resources. Aligning and standardizing terminology across stakeholders remains a prevailing challenge in invasion science. Here, we review and evaluate the multiple terms used in invasion science (e.g. 'non-native', 'alien', 'invasive' or 'invader', 'exotic', 'non-indigenous', 'naturalized, 'pest') to propose a more simplified and standardized terminology. The streamlined framework we propose and translate into 28 other languages is based on the terms (i) 'non-native', denoting species transported beyond their natural biogeographic range, (ii) 'established non-native', i.e. those non-native species that have established self-sustaining populations in their new location(s) in the wild, and (iii) 'invasive non-native' — populations of established non-native species that have recently spread or are spreading rapidly in their invaded range actively or passively with or without human mediation. We also highlight the importance of conceptualizing 'spread' for classifying invasiveness and 'impact' for management. Finally, we propose a protocol for classifying populations based on (1) dispersal mechanism, (2) species origin, (3) population status, and (4) impact. Collectively and without introducing new terminology, the framework that we present aims to facilitate effective communication and collaboration in invasion science and management of non-native species

Chelae regeneration in European alien crayfish Orconectes limosus (Rafinesque 1817)

Crayfish chelae have important functions, including prey capture and manipulation, reproduction, defense against predators, and inter- and intraspecific interactions. Consequently a loss of chelae often occurs. Adult specimens of invasive spiny-cheek crayfish (Orconectes limosus) were reared from February to November 2008 to observe the ability to regenerate lost chelae. Percent molt increments (PMI) of postorbital carapace length (POCL), chela length (ChL) and width (ChW) were compared between crayfish with and without chelae. Regenerated chelae were found to grow faster (ChL, ChW) than initial chelae and POCL. This trend occurs in both reproductive and non-reproductive O. limosus males and females. Values of 55.6 ± 0.06% for ChL and 50.0 ± 0.06% for ChW, compared to the initial chelae, were obtained in regenerated chelae of adult O. limosus after one molt. After two molts regenerated chelae reached 67.6 ± 0.07% ChL and 69.7 ± 0.08% ChW of values for initial chelae. Growth rate of regenerated chelae decreased with an increase in chelae dimensions. Regenerated chelae were found to be more narrow (significantly lower ChW/ChL ratio) than initial chelae. Regenerating of chelae did not have any influence on POCL growth. This study presents evidence that the invasive O. limosus possesses the ability of rapid substitution of lost chelae

THE FECUNDITY, TIME OF EGG DEVELOPMENT AND JUVENILE PRODUCTION IN SPINY-CHEEK CRAYFISH (ORCONECTES LIMOSUS) UNDER CONTROLLED CONDITIONS

We comprehensively describe the fecundity and time of embryonic development of the spiny-cheek crayfish (Orconectes limosus). Linear relationships between female size and ovarian fecundity, pleopodal fecundity, and production of juveniles at the 3rd stage, were confirmed. The ovarian fecundity was evaluated for the smallest as well as largest females in the sampled population (43-93 mm of body length); the number of oocytes (eggs) ranged widely, between 46 and 505. No significant difference was found between the ovarian and pleopodal fecundity observed just after egg laying. The value of the female gonadosomatic index just before laying was 4.2 ± 1.8% (0.8-7.7%). The mean diameter of eggs on female pleopods was 1.8 ± 0.2 mm (1.45-2.15 mm). A statistically significant difference was found between the numbers of eggs carried on individual pairs of pleopods. Mean time from laying to hatching was 46 ± 3.8 days (37-56 days), i.e. 647 ± 39.9 CTU (Celsius Temperature Units = degrees Celsius × days). Mean production of juveniles at the 3rd stage was found to be 135.7 ± 67.24 (15-243) juveniles. The early sexual maturation and also high number of juveniles at the 3rd stage per female gives this species a good predisposition for quick establishment in new localities

Evaluation of different marking methods for spiny-cheek crayfish (Orconectes limosus)

Different methods of marking were evaluated for Orconectes limosus (CL = carapace length, 12–37 mm) under laboratory conditions: the use of passive integrated transponders, visible implant elastomers, visible implant alphanumeric tags, and cauterization. High survival (> 90%) was obtained with all methods tested. Tag retention and readability were evaluated immediately after marking, before and after ecdysis, with moult increments and number of moults been recorded. Marking using cauterization negatively affects the percent moult increment (PMI) of crayfish. The average PMI of 15 ± 0.88% did not differ between males (15 ± 1.41 mm) and females (15 ± 1.12 mm). It was found that PMI gradually decreased with an increase in CL. Sixty-one moults were observed, with 12 crayfish (6 juveniles and 6 adults) presenting two moults. Time between moults varied from 3 to 7 weeks. CL was increased with over 28 ± 2.68% due to two moults. Three females moulted twice after successful hatching and carrying of juveniles

Chelae regeneration in European alien crayfish Orconectes limosus

Crayfish chelae have important functions, including prey capture and manipulation, reproduction, defense against predators, and inter- and intraspecific interactions. Consequently a loss of chelae often occurs. Adult specimens of invasive spiny-cheek crayfish (Orconectes limosus) were reared from February to November 2008 to observe the ability to regenerate lost chelae. Percent molt increments (PMI) of postorbital carapace length (POCL), chela length (ChL) and width (ChW) were compared between crayfish with and without chelae. Regenerated chelae were found to grow faster (ChL, ChW) than initial chelae and POCL. This trend occurs in both reproductive and non-reproductive O. limosus males and females. Values of 55.6 ± 0.06% for ChL and 50.0 ± 0.06% for ChW, compared to the initial chelae, were obtained in regenerated chelae of adult O. limosus after one molt. After two molts regenerated chelae reached 67.6 ± 0.07% ChL and 69.7 ± 0.08% ChW of values for initial chelae. Growth rate of regenerated chelae decreased with an increase in chelae dimensions. Regenerated chelae were found to be more narrow (significantly lower ChW/ChL ratio) than initial chelae. Regenerating of chelae did not have any influence on POCL growth. This study presents evidence that the invasive O. limosus possesses the ability of rapid substitution of lost chelae

Upstream expansion of round goby ( Neogobius Melanostomus

The round goby Neogobius melanostomus (Pallas, 1814) is one of the most problematic invasive fish species in recent years in Europe. It has proliferated from its native Ponto-Caspian region to several European river systems including their mouths and coastal brackish waters and was also introduced to and became widely established in the Great Lakes in North America. Despite recent reports about further invasions of round goby in the Odra and Vistula Rivers, including penetration of Baltic and North Seas, in the Elbe River this species was only recorded near its mouth close to Hamburg. Here we report the occurrence of round goby 622 km upstream from the previous record in Geesthacht (Germany) in the upper part of the Elbe River in Usti nad Labem (Czech Republic). This report illustrates the fast spread of round goby through several possible pathways, but the most certain is an introduction in ballast water