Cultivated Grassland Research Articles

Сталий розвиток лукопасовищного кормовиробництва в умовах змін клімату

The purpose. To develop effective models and systems of grassland forage production on natural forage lands of various soil and climatic regions of the country on the basis of adaptive technologies for the creation and use of hay-pasture grass stands. Methods. Analysis, synthesis, generalization, field experience. Results. Theoretical justification is made and ways are outlined for further perfecting grassland systems and techniques of building cultivated grasslands for rural communities with the purpose of intensification of milk cattle husbandry of Ukraine, solution of ecological problems and heightening economic efficiency of perspective for production of innovative development. Directions of production of high-quality feedstuff and approaches to preserving biodiversity in grassland systems in conditions of global climate fluctuations are shown. Conclusions. Modern development of grassland forage production should be based on ecological-biological principles of formation of the dominant adapted pascual agrophytocenosis and new systems of grazing depending on climatic and anthropogenous factors. Implementation of innovative developments will raise productivity of animal husbandry in public sector, will create premises to augmentation of cattle stock and stability improvement of traditional milk cattle husbandry to climate fluctuations.

Spatial and temporal trends of nitrate, chloride, and bromide concentration in an alluvial aquifer, North‐Central Texas, USA

AbstractThe Seymour aquifer consists of unconfined outcrops of sand and gravel in a semiarid, agricultural region of north‐central Texas in the United States of America. Most water samples collected from the aquifer in 2015 had nitrate concentrations above the drinking water standard of 44.3 milligrams per liter (mg/L). Generally, areas with high nitrate concentration in 2010 remained high in 2015, although the median dropped by 3.9 mg/L. The largest decreases in nitrate concentration—up to 97 mg/L (60%)—were observed in wells with depths less than the median of 13.1 meters (m). However, other wells, including depths above and below the median, showed increases in nitrate concentration of up to 40 mg/L (42%). In 2015, chloride concentrations in six wells exceeded the secondary contaminant level of 250 mg/L, and one well had a chloride concentration of 1,810 mg/L. Past and ongoing agricultural practices, including cultivation of native grassland, application of fertilizer, and irrigation with nitrate‐contaminated groundwater, help sustain overall high nitrate concentrations within the aquifer. Local conditions governing nitrogen inputs and dilution result in significant improvement or worsening of the nitrate problem over relatively short timeframes. The pumping of groundwater from the aquifer may facilitate mixing with groundwater of increased salinity that has been affected by the dissolution of evaporites in underlying Permian bedrock.

Evaluation of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) for mitigating soil N2O emissions after grassland cultivation

Grasslands within a crop rotation are temporary and thus subject to cultivation. This is typically accompanied by elevated soil N2O emissions due to residue decomposition and accumulation of mineral N in the soil for a period while N uptake by the succeeding crop is still low. This study evaluated a novel strategy for N2O mitigation, i.e., spraying of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) at 1 kg ha−1 on a grass-clover ley shortly before cultivation (+D). Tillage was performed by rotovation followed, two weeks later, by ploughing (RP), or by ploughing directly (P). We evaluated effects of DMPP and tillage strategy on net N mineralisation and dynamics of NH4+ and NO3−, and on soil N2O emissions, during the growing season of spring barley following spring cultivation of grass-clover. Rainfall between 14 April and 7 August 2015 was 298 mm, which was much higher than the 2000–2014 average for this period of 214 mm. Spraying grassland with DMPP before cultivation did not affect net N mineralization from residues, but significantly (p < 0.05) inhibited the oxidation of NH4+ for several weeks. Grassland cultivation significantly (p < 0.05) stimulated soil N2O emissions, and there was no difference in cumulative emissions between treatments RP–D (2.49 kg N ha−1) and P–D (1.76 kg N ha−1). Across both tillage treatments, spraying with DMPP significantly (p < 0.05) reduced cumulative N2O emissions. The reductions achieved for RP and P were on average 33 and 23%, respectively, but the effect for tillage treatment P was not statistically significant (0.05 < p < 0.1). The biomass and N uptake of spring barley were not significantly influenced by tillage or DMPP treatment. Results from this field validation were compared with results from previous experiments in controlled environments; the differences observed with respect to effects of residue distribution and DMPP treatments on soil N2O emissions were apparently related to soil NO3− availability. Where nitrification of residue-N is important for NO3− availability, our results indicate that spraying with DMPP prior to grassland cultivation has the potential to mitigate soil N2O emissions without affecting plant performance.

The Impact of Spatial Heterogeneity on Ecosystem Service Value in a Case Study in Liuyang River Basin, China

In previous studies the value of ecosystem services was evaluated microscopically by ecological indicators such as soil properties, biomass, carbon storage, oxygen release, water quality, and others. In this paper, the spatial heterogeneity of ecosystem services in Liuyang River basin was studied from the perspective of Geographic Information System (GIS) based spatial relationships by using a combination of geographic data and spatial analysis technologies. The Liuyang River basin was divided into grids with a resolution of 1km×1km. The weights of factors that affect the value of ecosystem services (such as topography, geological disasters, roads, scenic spots, vegetation coverage, and plant net primary productivity) were evaluated using the entropy method and analytic hierarchy process (AHP) in order to investigate the influence of natural and social factors on the value of ecosystem services in a quantitative manner. The results demonstrate that the value of ecosystem services is mainly affected by vegetation coverage, plant net primary productivity, and road network density. The value of ecosystem services grows with the increase in either vegetation coverage, plant net primary productivity, or road network density. Different types of land play different roles in ecosystem services. Cultivated land, grassland, and water each have significant supply and regulating functions while forest has significant regulating and supporting functions. The value of ecosystem services of cultivated land and water that are closely related to human activity is significantly influenced by spatial heterogeneity. In contrast, the effect of spatial heterogeneity on the value of ecosystem services of forest land and grassland that are located in mountains and hills, far away from the human accumulation zone, is insignificant.

A Holistic Approach to the Evaluation of the Montado Ecosystem Using Proximal Sensors.

The Montado is a silvo-pastoral system characterized by open canopy woodlands with natural or cultivated grassland in the undercover and grazing animals. The aims of this study were to present several proximal sensors with potential to monitor relevant variables in the complex montado ecosystem and demonstrate their application in a case study designed to evaluate the effect of trees on the pasture. This work uses data collected between March and June 2016, at peak of dryland pasture production under typical Mediterranean conditions, in twenty four sampling points, half under tree canopy (UTC) and half outside tree canopy (OTC). Correlations were established between pasture biomass and capacitance measured by a commercial probe and between pasture quality and normalized difference vegetation index (NDVI) measured by a commercial active optical sensor. The interest of altimetric and apparent soil electrical conductivity maps as the first step in the implementation of precision agriculture projects was demonstrated. The use of proximal sensors to monitor soil moisture content, pasture photosynthetically active radiation and temperature helped to explain the influence of trees on pasture productivity and quality. The significant and strong correlations obtained between capacitance and pasture biomass and between NDVI and pasture nutritive value (in terms of crude protein, CP and neutral detergent fibre, NDF) can make an important contribution to determination of key components of pasture productivity and quality and implementation of site-specific pasture management. Animal tracking demonstrated its potential to be an important tool for understanding the interaction between various factors and components that interrelate in the montado ecosystem and to support grazing management decisions.

Cost-benefit analysis for invasive species control: the case of greater Canada goose Branta canadensis in Flanders (northern Belgium).

BackgroundSound decisions on control actions for established invasive alien species (IAS) require information on ecological as well as socio-economic impact of the species and of its management. Cost-benefit analysis provides part of this information, yet has received relatively little attention in the scientific literature on IAS.MethodsWe apply a bio-economic model in a cost-benefit analysis framework to greater Canada goose Branta canadensis, an IAS with documented social, economic and ecological impacts in Flanders (northern Belgium). We compared a business as usual (BAU) scenario which involved non-coordinated hunting and egg destruction with an enhanced scenario based on a continuation of these activities but supplemented with coordinated capture of moulting birds. To assess population growth under the BAU scenario we fitted a logistic growth model to the observed pre-moult capture population. Projected damage costs included water eutrophication and damage to cultivated grasslands and were calculated for all scenarios. Management costs of the moult captures were based on a representative average of the actual cost of planning and executing moult captures.ResultsComparing the scenarios with different capture rates, different costs for eutrophication and various discount rates, showed avoided damage costs were in the range of 21.15 M€ to 45.82 M€ under the moult capture scenario. The lowest value for the avoided costs applied to the scenario where we lowered the capture rate by 10%. The highest value occurred in the scenario where we lowered the real discount rate from 4% to 2.5%.DiscussionThe reduction in damage costs always outweighed the additional management costs of moult captures. Therefore, additional coordinated moult captures could be applied to limit the negative economic impact of greater Canada goose at a regional scale. We further discuss the strengths and weaknesses of our approach and its potential application to other IAS.

Different responses of ecosystem carbon exchange to warming in three types of alpine grassland on the central Qinghai-Tibetan Plateau.

Climate is a driver of terrestrial ecosystem carbon exchange, which is an important product of ecosystem function. The Qinghai–Tibetan Plateau has recently been subjected to a marked increase in temperature as a consequence of global warming. To explore the effects of warming on carbon exchange in grassland ecosystems, we conducted a whole‐year warming experiment between 2012 and 2014 using open‐top chambers placed in an alpine meadow, an alpine steppe, and a cultivated grassland on the central Qinghai–Tibetan Plateau. We measured the gross primary productivity, net ecosystem CO 2 exchange (NEE), ecosystem respiration, and soil respiration using a chamber‐based method during the growing season. The results show that after 3 years of warming, there was significant stimulation of carbon assimilation and emission in the alpine meadow, but both these processes declined in the alpine steppe and the cultivated grassland. Under warming conditions, the soil water content was more important in stimulating ecosystem carbon exchange in the meadow and cultivated grassland than was soil temperature. In the steppe, the soil temperature was negatively correlated with ecosystem carbon exchange. We found that the ambient soil water content was significantly correlated with the magnitude of warming‐induced change in NEE. Under high soil moisture condition, warming has a significant positive effect on NEE, while it has a negative effect under low soil moisture condition. Our results highlight that the NEE in steppe and cultivated grassland have negative responses to warming; after reclamation, the natural meadow would subject to loose more C in warmer condition. Therefore, under future warmer condition, the overextension of cultivated grassland should be avoided and scientific planning of cultivated grassland should be achieved.

Are land use and short time climate change effective on soil carbon compositions and their relationships with soil properties in alpine grassland ecosystems on Qinghai-Tibetan Plateau?

Fencing and grass plantation are two key interventions to preserve the degraded grassland on the Qinghai-Tibetan Plateau (QTP). Climate warming and N deposition have substantially affected the alpine grassland ecosystems. However, molecular composition of soil organic carbon (SOC), the indicator of degradation of SOC, and its responses to climate change are still largely unclear. In this study, we conducted the experiments in three types of land use on the QTP: alpine meadow (AM), alpine steppe (AS), and cultivated grassland (CG) under 2°C climatic warming, 5 levels of nitrogen deposition rates at 8, 24, 40, 56, and 72kg N ha−1year−1, as well as a combination of climatic warming and N deposition (8kg N ha−1year−1). Our findings indicate that all three types of land use were dominated by O-alkyl carbon. The alkyl/O-alkyl ratio, aromaticity and hydrophobicity index of the CG were larger than those of the AM and AS, and this difference was generally stable under different treatments. Most of the SOC in the alpine grasslands was derived from fresh plants, and the carbon in the CG was more stable than that in the AM and AS. The compositions of all the alpine ecosystems were stable under short-term climatic changes, suggesting the short-term climate warming and nitrogen deposition likely did not affect the molecular composition of the SOC in the restored grasslands.

Bequest of the Norseman—The Potential for Agricultural Intensification and Expansion in Southern Greenland under Climate Change

The increase of summer temperatures and a prolonged growing season increase the potential for agricultural land use for subarctic agriculture. Nevertheless, land use at borderline ecotones is influenced by more factors than temperature and the length of the growing season, for example soil quality, as the increasing lengths of dry periods during vegetation season can diminish land use potential. Hence, this study focuses on the quality of the soil resource as possible limiting factor for land use intensification in southern Greenland. Physical and chemical soil properties of cultivated grasslands, reference sites and semi-natural birch and grassland sites were examined to develop a soil quality index and to identify the suitability of soils for a sustainable intensification and expansion of the agriculture. The study revealed that soils in the study area are generally characterized by a low effective cation exchange capacity (CECeff) (3.7 ± 5.0 meq 100 g−1), low pH CaCl2 (4.6 ± 0.4) and low clay and silt content (3.0 ± 1.0% and 38.2 ± 4.7%, respectively). Due to the high amount of coarse fraction (59.1 ± 5.8%) and the low amount of soil nutrients, an increasing threat of dry spells for soils and yield could be identified. Further, future land use intensification and expansion bears a high risk for concomitant effects, namely further soil acidification, nutrient leaching and soil degradation processes. However, results of the soil quality index also indicate that sites which were already used by the Norseman (980s–1450) show the best suitability for agricultural use. Thus, these areas offer a possibility to expand agricultural land use in southern Greenland.

Responses of soil respiration to soil management changes in an agropastoral ecotone in Inner Mongolia, China.

Studying the responses of soil respiration (R s) to soil management changes is critical for enhancing our understanding of the global carbon cycle and has practical implications for grassland management. Therefore, the objectives of this study were (1) quantify daily and seasonal patterns of R s, (2) evaluate the influence of abiotic factors on R s, and (3) detect the effects of soil management changes on R s. We hypothesized that (1) most of daily and seasonal variation in R s could be explained by soil temperature (T s) and soil water content (S w), (2) soil management changes could significantly affect R s, and (3) soil management changes affected R s via the significant change in abiotic and biotic factors. In situ R s values were monitored in an agropastoral ecotone in Inner Mongolia, China, during the growing seasons in 2009 (August to October) and 2010 (May to October). The soil management changes sequences included free grazing grassland (FG), cropland (CL), grazing enclosure grassland (GE), and abandoned cultivated grassland (AC). During the growing season in 2010, cumulative R s for FG, CL, GE, and AC averaged 265.97, 344.74, 236.70, and 226.42 gC m−2 year−1, respectively. The T s and S w significantly influenced R s and explained 66%–86% of the variability in daily R s. Monthly mean temperature and precipitation explained 78%–96% of the variability in monthly R s. The results clearly showed that R s was increased by 29% with the conversion of FG to CL and decreased by 35% and 11% with the conversion of CL to AC and FG to GE. The factors impacting the change in R s under different soil management changes sequences varied. Our results confirm the tested hypotheses. The increase in Q 10 and litter biomass induced by conversion of FG to GE could lead to increased R s if the climate warming. We suggest that after proper natural restoration period, grasslands should be utilized properly to decrease R s.

Horse Welfare and Natural Values on Semi-Natural and Extensive Pastures in Finland: Synergies and Trade-Offs

In several regions in Europe, the horse is becoming a common grazer on semi-natural and cultivated grasslands, though the pasturing benefits for animals and biodiversity alike are not universally appreciated. The composition of ground vegetation on pastures determines the value of both the forage for grazing animals as well as the biodiversity values for species associated with the pastoral ecosystems. We studied three pastures, each representing one of the management types in southern Finland (latitudes 60–61): semi-natural, permanent and cultivated grassland. All have been grazed exclusively by horses for several decades. We aimed to evaluate feeding values and horses’ welfare, on the one hand, and impacts of horses on biodiversity in boreal conditions, on the other. Though there were differences among the pastures, the nutritional value of the vegetation in all three pastures met the energy and protein needs of most horse categories through the whole grazing season. Some mineral concentrations were low compared to the requirements, and supplementation of Cu, Zn and Na is needed to balance the mineral intake. Only minor injuries or health problems were observed. All metrics of biological values, as well as number of species eaten by horses, were particularly high in a semi-natural pasture compared to other pasture types. The highest ratio of species cover preferred by horses to the total cover was found in the permanent pasture, while at the regularly re-seeded pasture, there was a particularly high cover of species, indicating low biodiversity values on grassland. There was, therefore, a trade-off between the quantity of forage and biological values in pastures, but not in quality. The results provide clear indication both for the suitability of the studied pasture types to horses and for grazing of horses for biodiversity management. In each pasture type, specific management is needed to simultaneously achieve objectives of adequate pasturing and biodiversity. The short duration (only one grazing season) must be considered when applying the results.

Renovation and conversion of permanent grass-clover swards to pasture or crops: Effects on annual N2O emissions in the year after ploughing

The need for improved herbage yield and forage quality, on intensively managed grassland, in dairy farming systems, often results in land being brought into tillage, either by grassland reseeding or conversion to arable cropping (particularly maize (Zea mays L.) for silage). However, both options are likely to increase the greenhouse gas emissions (GHG) after grassland cultivation, particularly when this involves ploughing, although there is limited information about the level of emissions. In order to estimate whether the time of ploughing and type of forage crop would affect the annual emissions of the important GHG nitrous oxide (N2O) in the year after soil disturbance of grassland, a field experiment was established on a Eutric Luvisol in northern Germany. The three factorial experiment comprised the effect of land use management (four treatments: ploughing and reseeding in autumn; ploughing and reseeding in spring, ploughing and conversion to maize in spring; control treatment of intact permanent grassland); the effect of nitrogen (N) fertilizer input (two treatments: 0 and 240kgNha−1year−1 applied as cattle slurry); and the experimental year (two years). Treatments were arranged with three replicates in a randomized block design. N2O emissions were measured on a weekly basis with the static chamber method and N drainage during winter was estimated using suction cups. Thus, direct and indirect N2O emissions (viaN leaching) were calculated per ha as well as per unit of forage yield. Results showed that ground-frost and freeze-thaw cycles were major drivers of enhanced N2O fluxes during the winter following ploughing and reseeding of grassland in autumn, resulting in the highest direct emissions of 21.31kgN2O-Nha−1year−1. Emissions following grassland ploughing in spring were mainly driven by high soil mineral N-concentrations but with maximum figures of 3.90 and 6.32kgN2O-Nha−1year−1 after reseeding and conversion to maize respectively. Emissions in the intact permanent grassland were lowest in both years. Forage yield related emissions were also highest for grassland ploughing and reseeding in autumn and lowest for intact permanent grassland, but with no significant differences for reseeding and maize cultivation after grassland ploughing in spring. Application of slurry increased annual N2O emissions, particularly when applied in the year of reseeding, but with a lower calculated emission factor as advised by the IPCC guidelines for N fertilizers. We conclude that sustaining highly productive permanent grass-clover swards with moderate N fertilization and without tillage is the best option for ‘climate-smart forage production’ followed, when unavoidable, by tillage operations only in early spring for direct grassland reseeding, or delayed reseeding using a high yielding forage crop like maize.

Contrasting bacterial communities in two indigenous Chionochloa (Poaceae) grassland soils in New Zealand.

The cultivation of grasslands can modify both bacterial community structure and impact on nutrient cycling as well as the productivity and diversity of plant communities. In this study, two pristine New Zealand grassland sites dominated by indigenous tall tussocks (Chionochloa pallens or C. teretifolia) were examined to investigate the extent and predictability of variation of the bacterial community. The contribution of free-living bacteria to biological nitrogen fixation is predicted to be ecologically significant in these soils; therefore, the diazotrophic community was also examined. The C. teretifolia site had N-poor and poorly-drained peaty soils, and the C. pallens had N-rich and well-drained fertile soils. These soils also differ in the proportion of organic carbon (C), Olsen phosphorus (P) and soil pH. The nutrient-rich soils showed increased relative abundances of some copiotrophic bacterial taxa (including members of the Proteobacteria, Bacteroidetes and Firmicutes phyla). Other copiotrophs, Actinobacteria and the oliogotrophic Acidobacteria showed increased relative abundance in nutrient-poor soils. Greater diversity based on 16S rRNA gene sequences and the Tax4Fun prediction of enhanced spore formation associated with nutrient-rich soils could indicate increased resilience of the bacterial community. The two sites had distinct diazotrophic communities with higher diversity in C. teretifolia soils that had less available nitrate and ammonium, potentially indicating increased resilience of the diazotroph community at this site. The C. teretifolia soils had more 16S rRNA gene and nifH copies per g soil than the nutrient rich site. However, the proportion of the bacterial community that was diazotrophic was similar in the two soils. We suggest that edaphic and vegetation factors are contributing to major differences in the composition and diversity of total bacterial and diazotrophic communities at these sites. We predict the differences in the communities at the two sites will result in different responses to environmental change.

Effects of warming and nitrogen deposition on CH4, CO2 and N2O emissions in alpine grassland ecosystems of the Qinghai-Tibetan Plateau

Increases in nitrogen (N) deposition along with climate warming can change the dynamics of carbon and nitrogen in the soil, and alter greenhouse gases (GHGs) fluxes. To examine how N deposition and warming affect GHGs (CH4, CO2 and N2O) fluxes in alpine grasslands, we conducted experiments in an alpine meadow (AM), alpine-steppe (AS), and alpine cultivated grassland (CG) on the Qinghai-Tibetan Plateau (QTP). We simulated N deposition by treating soil with ammonium nitrate (NH4NO3) (8kgNha−1year−1), a warming treatment using an open top chamber (OTC) was carried out, and a combined treatment of warming and N deposition (8kgNha−1year−1) was conducted. The GHGs were collected during early, peak, and late plant growing seasons, i.e., May, August, and October of 2015, respectively, using a static chamber. We found, in general, neither N deposition nor warming solely altered CH4 and N2O fluxes in the alpine grasslands. The N deposition under warming conditions reduced CO2 emission significantly. The reduction of CO2 emission was most significant in the alpine steppe. The effects of climatic warming and N deposition on the GHGs varied greatly across the grassland types and the growing seasons. The cultivated grasslands were much more unstable than the native grasslands in CH4 uptake. In can be concluded the N deposition associated with human activities may buffer the CO2 emission in the alpine grassland ecosystems in terms of climate changes on the QTP.

Agricultural land use shapes habitat selection, foraging and reproductive success of the Lesser Spotted Eagle Clanga pomarina

Anthropogenic loss of biodiversity is often indicated by the disappearance of top predators. However, some of them have adapted to man-made agricultural landscapes. Among raptors, one such example is the Lesser Spotted Eagle. We compiled an exhaustive data set on foraging habitat composition of this species by direct field mapping and detailed land cover maps to study the effect of various agricultural management practices on its occupancy of home ranges and productivity, as well as on its habitat utilization and hunting success. Home ranges of the Lesser Spotted Eagle contained more natural grasslands (7.6%) and other agricultural biotopes (29.9%) than expected by random, and they preferred to breed close to managed agricultural biotopes. They hunted preferably on grasslands, where they spent 86% of their time, especially on managed grasslands, but avoided arable fields. In total, 51% of the Lesser Spotted Eagle attacks were successful, and we detected no differences in hunting success among habitats. Nests of successfully breeding birds were surrounded by more crops/cultivated grassland on a rotational basis (19.0%), as well as by managed natural grassland (1.1%), than those of unsuccessful pairs (16 and 0.7%, respectively). We also detected a negative impact of oilseed rape fields and mowed cultivated grassland on the reproductive success of the Lesser Spotted Eagle, but these effects were not consistent over the years. Our results suggest that, although the Lesser Spotted Eagle is well adapted to foraging in traditional farmland, it is threatened by changes in agricultural practices and an increasing sown area of some crops, such as oilseed rape. Cultivation of various crops and retaining of grasslands, interspersed with set-aside and non-agricultural habitat patches, promoted by the European Union greening policy, would be favourable to the Lesser Spotted Eagle.

Study on Driving Mechanisms of Land Use Change in the Coastal Area of Jiangsu, China

ABSTRACT Bao, G.Y.; Huang, H.; Gao, Y.N., and Wang, D.B., 2017. Study on driving mechanisms of land use change in coastal area of Jiangsu, China. In: Lee, J.L.; Griffiths, T.; Lotan, A.; Suh, K.-S., and Lee, J. (eds.), The 2nd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 79, pp. 104–108. Coconut Creek (Florida), ISSN 0749-0208. Based on the 5 periods of satellite images, land use structure and changes of 3 cities in the Jiangsu coastal area were analyzed, and the relationship between land use structure and environmental factors was analyzed by “CLUE-S model + Logistic regression”. The results showed that, for land use change in the past 15 years, the changes in cultivated land, grassland and construction land were the highest. Land use change is mainly located in urban and surrounding areas, followed by farmland mainly located in the coastal zone. This study uses GIS spatial analysis and CLUE-S + Logistic regression model analysis, correlation analysis and regressio...

Leguminous species sequester more carbon than gramineous species in cultivated grasslands of a semi-arid area

Abstract. The establishment of grasslands on abandoned cropland has been proposed as an effective method to mitigate climate change. In this study, five cultivated grasslands (three leguminous species and two gramineous species), one abandoned cropland, and one natural grassland were studied to examine how soil organic carbon (SOC) sequestration rate and sequestration efficiency change in a semi-arid area in China. Our results showed that leguminous grasslands had greater total biomass (above- and belowground biomass), SOC storage, SOC sequestration rate, and efficiency than gramineous grasslands, abandoned cropland, and natural grassland during the experimental period. The largest soil carbon (C) accumulation in leguminous grassland was mainly attributed to the capacity to incorporate C and the higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grassland sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grassland in arid and semi-arid areas. Our results provide a reference for ecological management in arid and semi-arid areas.

Microbial N Transformations and N2O Emission after Simulated Grassland Cultivation: Effects of the Nitrification Inhibitor 3,4-Dimethylpyrazole Phosphate (DMPP).

Residue incorporation following grassland cultivation can lead to mobilization of large pools of N and potentially to significant N losses via leaching and N2O emissions. This study proposed a mitigation strategy of applying 3,4-dimethylpyrazole phosphate (DMPP) prior to grassland cultivation and investigated its efficacy in a laboratory incubation study. DMPP inhibited the growth and activity of ammonia-oxidizing bacteria but had no adverse effects on ammonia-oxidizing archaea and denitrifiers. DMPP can effectively reduce the potential for leaching of NO3- derived from residue decomposition, while the effect on reducing N2O emissions will be significant only when soil NO3- availability is limiting. Our findings provide insight into how DMPP affects soil nitrifier and denitrifier populations and have direct implications for improving N use efficiency and reducing environmental impacts during grassland cultivation.

Butterfly Species Diversity in Protected and Unprotected Habitat of Ise Forest Reserve, Ise Ekiti, Ekiti State

This study investigated butterfly diversity in the protected area (PA) and unprotected area (UPA) of Ise Forest reserve, Ise Ekiti, Ekiti State, using sweep net along existing trails. Butterfly species seen in the study sites were captured and released after proper identification was made. The results indicated that a total of 837 butterflies were identified in the study sites with 661 species observed in PA and 176 species in UPA. Butterfly species diversity was significantly different (p≤0.05) between PA and UPA. Shannon diversity index was higher in PA (3.59) than UPA (3.27) as against Menhinick’s index, higher in UPA (2.11) than in PA (1.52). Likewise, 10 families of butterflies were recorded in PA and 8 families in UPA. The family with highest species occurrence was Satyridae (17.9%) in PA and Lycaenidae in UPA with 20.1%. Butterfly families’ diversity was not significant (p≥0.05) between the two study sites. Ise Forest Reserve recorded approximately 6.6% of all butterflies recorded in West Africa. The findings indicated that mature secondary and regenerated forests supported high butterfly diversity and species richness, while cultivated land and grassland had a negative impact on butterfly community suggesting the negative effect of agricultural activities on the ecosystem.

Land-use effects on organic and inorganic carbon patterns in the topsoil around Qinghai Lake basin, Qinghai-Tibetan Plateau

Soil carbon (C) pool contains organic carbon (SOC) and inorganic carbon (SIC). A detailed understanding of SOC and SIC is meaningful and essential for precisely assessing the effects of land-use on soil C stocks. Alpine grassland around Qinghai Lake basin has experienced extensive land-use changes due to the cultivation of native grassland and vegetation recovery on cropped land. However, limited information is available about the changes and distribution patterns of soil C pool with land-use in this region. Here, three land-use types were chosen, including natural alpine grassland (NG), and a pair of restored grassland (RG) and farmland (FL), to examine the effects of cultivation and restoration on SOC and SIC horizontal patterns and vertical distributions in the upper 30cm soil layer. Land-use changed the ratio of SOC/SIC without affecting the net soil total C accumulation in this area. The NG had the highest SOC (96.0MgCha−1) and lowest SIC (19.8MgCha−1) stocks, while the FL had the opposite result, with the average of SOC and SIC stocks was 65.0 and 57.7MgCha−1, respectively. After 10-year restoration, SOC stock increased to 73.2MgCha−1, while SIC decreased to 47.8MgCha−1 in the RG. The vertical distribution of SOC and SIC changed sharply with depth in the NG but gently in the RG, and with little changes in the FL. Stepwise regression analysis manifested that soil nitrogen and pH were the main determinants for the redistribution patterns of SOC and SIC with land-use. In addition, ordinary regression analysis revealed a significant negative correlation between SIC content and aboveground biomass of the respective vegetation. The results demonstrated that land-use had affected the horizontal and vertical patterns of SOC and SIC synchronously, and indicated SIC stocks played crucial roles for estimating the C sequestration capacity in the restoration and farmland ecosystems around Qinghai Lake basin. Moreover, the results of this study provided an interesting snapshot of the compensation relationship between SOC and SIC stocks with land-use, and suggested that the changes of soil properties and plant above- and belowground biomass resulting from cultivation and restoration were potentially responsible for the transformation of soil C forms.