Artificial Dispersal as a Restoration Tool in Meadows: Sowing or Planting?

Habitat fragmentation and the abandonment of former agricultural practices have led to extremely low dispersal rates for plant species growing in traditionally managed hay meadows in Sweden. Historically, seed dispersal between populations was maintained by hay movement, grazing animals, and farmers sharing their equipment. Because these means of dispersal typically are no longer occurring, artificial dispersal using seeds and plug-plants is tested here as a restoration tool. In this study, we chose two perennial herbs commonly occurring in meadows as test species, viz, Hypochoeris maculata L. (Asteraceae) and Succisa pratensis Moench. (Dipsacaceae). We found that plug-plant transplants were twice as effective as seed sowing for both species. The seed collection site was found to be important for seed-based establishment and survival; consequently, the choice of donor meadow is important when acquiring seeds used for restoration. We also found that survival of plants introduced as seeds was generally lower at sites harboring species favored by nitrogen as well as at sites in later successional phases. Both methods of introducing meadow species worked well, even though long-term establishment may well be more successful with the plug-plant method due to higher plug-plant establishment 2 years after introduction in the field.     

Effect of feeding long or short wheat hay v. wheat silage in the ration of lactating cows on intake,milk production and digestibility

The objective of this study was to evaluate in lactating cows the effect of either chopping or ensiling of wheat roughage on: intake, digestibility, lactation performance and animal behavior. Three groups of 14 lactating cows each, were fed total mixed rations (TMRs) based on either long wheat hay (HL), short wheat hay (HS) or wheat silage (SI), as the sole roughage source (30% of TMR dry matter (DM)). Parameters examined: sorting behavior, DM intake, milk yield and composition, rumination, recumbence, average daily rumen pH, digesta passage rate, and in-vivo digestibility. Performance data was summarized by day and analyzed using a proc-mixed model. The content of physically effective neutral detergent fiber (peNDF) was similar in the HL and SI and lower in the HS, resulting in similar differences among the three corresponding TMRs. In vitro DM digestibility of wheat silage was higher than that of the two hays (65.6% v. 62.8%) resulting in higher in vitro DM digestibility of the SI-TMR compared with the hay-based TMRs (79.3 v. 77.0%). HS-TMR was better than HL- or SI-TMRs at preventing feed sorting by cows after 12 or 24 h eating of the diets. Cows fed HS-TMR consumed more DM and NDF but less peNDF than the other two groups. Average daily rumen pH was similar in the three groups, but daily rumination time was highest in the cows fed HS-TMR. Rumen retention time was longest in cows fed HL-TMR. DM digestibility in cows fed SI-TMR was higher than that of HS and HL groups (65.2%, 61.8% and 62.4%, respectively), but NDF digestibility was similar in the three treatments. The highest intake of digestible DM was observed in cows fed SI-TMR, HS cows were intermediate and HL cows were the lowest. Consequently, cows fed SI-TMR had higher yields of milk, 4% fat corrected milk and energy-corrected milk (47.1, 42.9 and 43.2 kg/day, respectively) than cows fed HS-TMR (45.7, 41.0 and 41.0 kg/day, respectively) or HL-TMR (44.1, 40.3 and 40.3 kg/day, respectively). Net energy production (NE_L+M+gain) per kg DM intake was highest in the SI-TMR, lowest in the HS-TMR and intermediate in the HL-TMR (1.52, 1.40 and 1.45, respectively). Animal welfare, as expressed in daily recumbence time and BW gain was similar in the SI and HS groups and higher than the HL cows.     

Near‐natural methods promote restoration of species‐rich grassland vegetation—revisiting a road verge trial after 9 years

The present loss of species‐rich grasslands makes it vital to restore these valuable habitat types, including novel habitat variants such as road verges. Due to the lack of knowledge on long‐term outcomes of restoration initiatives, well‐designed studies comparing different restoration methods are needed. In this study, we examined fine‐scale vegetation recovery patterns over 9 years in a field experiment with several near‐natural restoration methods (adding local seed mixtures, transferring hay from local grasslands using hard or light raking, and natural regeneration) in a road verge. We compared this to standard revegetation (hydroseeding species‐poor commercial seed mixtures). We found major temporal changes in vegetation restored by local seed or hay transfer, before it gradually became more similar to the donor grasslands and seed mixtures, which served as references for the experiment. Natural (spontaneous) regeneration with seed dispersal from surroundings gave similar results, whereas areas revegetated using standard methods became more dissimilar to the reference sites during the study period. The main variation in species composition reflected the contrast between local donor grasslands and seed mixtures and the species‐poor early successional grasslands. We conclude that near‐natural methods (hay transfer and seeding) successfully restored species‐rich grassland, including road verges. This study underlines the importance of comparing several treatments over a sufficiently long period to assess their success in restoring species‐rich grassland.     

Effects of soybean hulls inclusion on intake, total tract nutrient utilization and ruminal fermentation of goats fed spineless cactus (Opuntia ficus-indica Mill) based diets

A study was conducted to evaluate soybean hulls (SH) as a replacement of tifton bermudagrass hay (TH) in diets of goats containing high levels of spineless cactus. Ten mature bucks (five ruminally fistulated) were used in a 5 × 5 Latin square experiment with 21-day periods. Soybean hulls replaced 0, 250, 500, 750 and 1000 g/kg of TH in the experimental diets. All diets contained 600 g/kg spineless cactus (dry matter basis). Intakes of dry matter (DM), organic matter (OM) and non-fiber carbohydrates and chewing activities decreased linearly (P < 0.01) as the level SH in the diet increased. In vivo digestibility of DM, OM and neutral detergent fiber increased linearly (P < 0.01) as the level of SH in the diet increased. Addition of SH linearly increased (P < 0.05) N retention without affecting microbial N supply (g/kg of digestible OM intake) to the small intestine. Ruminal pH and NH₃-N decreased linearly (P < 0.05) while total volatile fatty acid (VFA) concentration increased linearly (P < 0.05) as proportion of SH in diets increased. It was concluded that inclusion of SH in cactus-based diets had a negative impact on intake and chewing activities but improved total tract nutrient utilization by goats. Replacing TH with SH resulted in a concentrate type ruminal fermentation (i.e., low ruminal pH and high VFA concentration).     

Effects of physically effective fibre concentration of diets consisting of hay and slowly degradable concentrate on chewing activity in mid lactation dairy cows under constant intake level

Abstract

Four ruminally cannulated Holstein cows (BW 615 kg) in mid lactation were used to evaluate the effects of fibre level (39, 32, 28, 24 and 19% physically effective NDF [peNDF] in DM) in diets consisting of hay and slowly degradable concentrate on chewing activity, under a constant intake level (18 kg DM · d^?1). The different dietary fibre concentrations were achieved by adjusting the hay to concentrate ratio. The above-mentioned levels of peNDF corresponded to 25, 40, 50, 60 and 70% concentrate respectively. The diets with decreasing share of concentrate were offered in sequence according to the progressive lactation of the cows. A decrease of the peNDF from 39 – 28% reduced total chewing and rumination time, total number of chews and number of boluses per day as well as chewing time spent per unit of DM. No significant change in chewing behaviour occurred between peNDF level of 28 and 24%. This peNDF level (i.e., 24%) might be considered as a tolerable fibre level. A further reduction of peNDF to 19% led to a significant reduction of chewing activity. This level can be considered as critical for chewing activity and presumably for the rumen health. The chewing parameters correlated linearly to fibre and non-fibre carbohydrates with R² of 23 – 51%.     

Occurrence of thermophilic actinomycetes in natural substrates in Nigeria

Thermophilic actinomycetes were isolated from 163 (48.95%) of 333 samples of vegetable substrates and soil from different sites in Anambra and Enugu States in Nigeria.Thermoactinomyces (Tha.) vulgaris was the most common, occurring in 32.4% of samples whileTha. thalpophilus was isolated from 20.1%.Tha. sacchari, Saccharomonospora (Sam.) viridis andSaccharopolyspora (Sap.) rectivirgula were isolated from 3–10.5% of the samples examined.Streptomyces (Stm.) thermovulgaris occurred in 2.7% andThermomonospora spp. in 0.6% of samples. Except forStm. thermovulgaris and, perhaps,Thermomonospora spp., all the species isolated are known to be allergenic in man. The five known allergenic species were abundant in hay and maize silage.T. vulgaris andT. thalpophilus were also frequently isolated from rice straw.Tha. vulgaris, Tha. thalpophilus andSap. rectivirgula were all most numerous in hay whileTha. sacchari was most numerous in maize silage. The widespread occurrence of thermophilic actinomycetes in Nigeria emphasizes the need for investigation of their role in allergic respiratory disorders.     

Effects of topsoil removal,seed transfer with plant material and moderate grazing on restoration of riparian fen grasslands

Question: How do moderate grazing, topsoil removal and hay transfer affect species diversity and abundance on a eutrophic fen grassland site? Location: Northern Germany. Method: A three-factorial field experiment with the factors grazing, topsoil removal and hay transfer of diaspore-rich material was established in 2001. Soil nutrients and seed bank were analysed at the beginning of the experiment, species composition and vegetation development was monitored for four years (2002–2005). Results: Topsoil removal had a significant effect on the abundance of different plant species groups: resident vegetation of agricultural grasslands was suppressed, while clonal reed species were facilitated in recolonising the area. The establishment of regionally rare and endangered species of nutrient-poor fens and wet meadows introduced with hay was achieved mainly on plots with topsoil removal, with the exception of Rhinan-thus angustifolius, which also established on plots with intact topsoil. Effects of grazing after four years of experiments were of minor influence on species composition. Conclusion: The establishment of target plant species of nutrient-poor fens is most successful when both an adequate number of viable diaspores and suitable sites for germination and establishment are available. In our experiment this was achieved by the combination of topsoil removal and hay transfer. We recommend this combination, together with continuous management (grazing/cutting), for further restoration in fen grasslands.     

Retrospective and predictive systems of information on airborne pollen concentrations in relation to hay fever

Summary In this survey, the most important aspects concerning information on airborne pollen concentrations in relation to hay fever are reported. Six of these aspects are briefly discussed. They are: target group, “spectivity”, subject exactness, routes, frequency. These aspects of information system can concern airborne pollen and/or pollinosis. The “Leiden” system has two flows of information: daily hay-fever forecast and weekly pollen bulletin.