Objective: To evaluate the floristic composition and nutritional quality of a meadow used for grazing of hair sheep under the agroecological conditions of the dry Colombian Caribbean. Material and ...Methods: The study was conducted at the Motilonia Research Center, of the Colombian Corporation of Agricultural Research AGROSAVIA. Curves of species accumulation and abundance range were made for the data analysis through the statistical program Qeco, as well as the Student’s t-test for independent samples with Infostat. Results: Thirteen plant species were recorded in the meadow, 12 were identified at species level and one at genus level. The representation, in terms of family was given by Poaceae (30,8 %), Fabaceae (30,8 %), Cyperaceae (7,7 %), Boraginacea (7,7 %), Portulacaceae (7,7 %), Apocynaceae (7,7 %), and Amaranthaceae (7,7 %). The floristic composition in the entire meadow (control transect) was different, in terms of number of species with regards to the feeding sites of the flock (p = 0,0249). This proves that the animal made a preliminary selection of the forage. Conclusions: Thirteen plant species were recorded in the meadow and 12 were identified at species level. In this study, the applied methodology for the determination of the floristic composition of the meadow, with the use of the transects and the cross, was accurate for the identification of the dominant species in the enclosed pastures versus those that were most visited by the animals.
The Brazilian semiarid region presents very heterogeneous natural conditions of climate, soil, topography and vegetation, forming a mosaic of unique ecosystems. This research aims to carry out a ...phytosociological analysis of the tree-shrub stratum of two Caatinga areas in the Sertão (backlands) of Alagoas. The experiment was carried out in the municipalities of Olho D ‘Água do Casado (area I) and Delmiro Gouveia (area II), state of Alagoas, a quantitative evaluation of the vegetation was carried out by contiguous plots within an area of 1.0 ha. The phytosociological parameters analyzed were Density, Relative Frequency and Dominance, Importance Value, Shannon-Weaver Diversity Index and Aggregation. The families with the greatest number of species are Mimosaceae and Bignoniaceae in area I and Mimosaceae and Anacardiaceae in area II, with a higher relative density for the species Tabebuia sp. and Schinopsis brasiliensis, respectively; the species Myrcia sp., Tabebuia sp. and Pilosocereus pachycladus in area I presented a higher value of importance, standing out Schinopsis brasiliensis, Pilosocereus gounellei and Pityrocarpa moniliformis in area II. The Shannon-Weaver (H’) diversity index is considered high in area I and II when compared to other areas of Caatinga; similarly, floristic richness was considered similar in both areas.
Changing climatic conditions in north-western Europe require adaptations in management of ley grassland, requiring new grass-legume mixture designs in response to increased variability in ...precipitation and warmer summers. Evaluation of lucerne (Medicago sativa L.)-grass swards with the grasses cocksfoot (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.), which are potentially more tolerant to summer water shortage, have yet to be evaluated under the agro-climatic conditions of north-western Europe. We tested these grasses in three-species swards and binary lucerne grass swards and compared them against pure stands and a standard lucerne-grass mixture. The study was conducted in eight environments resulting from the combination of four soil sites during the two full main production years 2020 and 2021 with an annual precipitation range of 416–839 mm. Swards were harvested three to five times annually and the accumulated herbage dry matter (DM) and nitrogen (N) yields, as well as species proportions were recorded. We found an average yield of 11.1 t DM ha-1 and no significant differences in herbage DM yields between lucerne pure stands and the different mixture swards. This pattern was stable irrespective of environmental conditions, but in general herbage yield and aboveground N yield were affected by precipitation amount. Swards with cocksfoot had a greater grass proportion than those with tall fescue. The N yield of lucerne-grass swards was lower and declined as the grass proportion increased, and reached on average 353 kg N ha-1. The maximum N yield of lucerne pure stands was 547 kg N ha-1. Species mixtures yielded higher than expected from the pure stands (net mixture effect, NE) pointing at overyielding. Consequently, synergistic interspecific interactions occurred but did not lead to transgressive overyielding. The results indicate that the inclusion of grass species with tolerance to water shortage into lucerne-based swards offers the potential to diversify grasslands without losses of agronomic potential, at least during the first two main production years.
•Lucerne pure stands were tested against binary and three-species mixtures with tall fescue and cocksfoot.•Precipitation had a strong positive influence on the productivity of all mixed swards.•Positive interspecific interactions in lucerne-grass swards resulted in overyielding without transgressive overyielding.•Grass identity effects were of less importance for yield and cocksfoot was more competitive than tall fescue.
Harvested forage is the main raw feed for ruminant animals in Sweden, and is commonly cultivated in mixed stands of legume and grass species. The fraction of legume on a dry matter basis, known as ...botanical composition (BC) is a very important indicator of forage quality. In this study, hyperspectral imaging and near-infrared spectrometer (NIRS) based methods were used to estimate BC, to overcome the shortcomings of hand separation, which is time and resource consuming. Timothy and red clover mix samples were collected from different harvests in 2017–2019 from multiple sites in Northern Sweden and hand separated. The samples were synthetically mixed to 11 different BC levels, i.e., 0–100 % clover content. Two different instruments (Specim shortwave infrared (SWIR) hyperspectral imaging system and Foss 6500 spectrometer) were used to collect spectral data of samples milled to two levels of coarseness. Three different regression analyses: partial least squares regression (PLSR), support vector regression (SVR) and random forest regression (RFR), were used to build BC estimation models. The effects of the milling particle sizes and the different instruments on the performances of the models were compared. The data from second harvest in 2019 were used for independent validation as evaluation, and the rest of data were randomly split for model calibration (75 %) and validation (25 %). The models were iteratively run 1000 times with different splits, to check the effect from the splitting of calibration and validation datasets. Among different regression analyses, PLSR performed best, with mean Nash-Sutcliffe efficiency (NSE) for model evaluation from 0.76 to 0.87, varying for different instruments and milling sizes. Finer milling made the model accuracies slightly higher. This study developed quick and robust methods to determine the BC of timothy grass and red clover mixtures, which can provide useful information for farmers or researchers.
Display omitted
•Forage BC can be estimated by hyperspectral and NIRS data.•Samples with higher clover content absorbed more light.•Among different regression models, PLSR performed the best.•Finer milling produced higher regression modelling accuracies.•The hyperspectral sensor performed slightly better than the NIRS sensor.
A future higher risk of severe flooding of streams and rivers has been projected to change riparian plant community composition and species richness, but the extent and direction of the expected ...change remain uncertain. We conducted a meta‐analysis to synthesize globally available experimental evidence and assess the effects of increased flooding on (1) riparian adult plant and seedling survival, (2) riparian plant biomass and (3) riparian plant species composition and richness. We evaluated which plant traits are of key importance for the response of riparian plant species to flooding. We identified and analysed 53 papers from ISI Web of Knowledge which presented quantitative experimental results on flooding treatments and corresponding control situations. Our meta‐analysis demonstrated how longer duration of flooding, greater depth of flooding and, particularly, their combination reduce seedling survival of most riparian species. Plant height above water level, ability to elongate shoots and plasticity in root porosity were decisive for adult plant survival and growth during longer periods of flooding. Both ‘quiescence’ and ‘escape’ proved to be successful strategies promoting riparian plant survival, which was reflected in the wide variation in survival (full range between 0 and 100%) under fully submerged conditions, while plants that protrude above the water level (>20 cm) almost all survive. Our survey confirmed that the projected increase in the duration and depth of flooding periods is sufficient to result in species shifts. These shifts may lead to increased or decreased riparian species richness depending on the nutrient, climatic and hydrological status of the catchment. Species richness was generally reduced at flooded sites in nutrient‐rich catchments and sites that previously experienced relatively stable hydrographs (e.g. rain‐fed lowland streams). Species richness usually increased at sites in desert and semi‐arid climate regions (e.g. intermittent streams).
Harwanto, Karti PDMH, Suwardi, Abdullah L. 2023. Native plant composition and soil microfauna in limestone post-mining land as potential for development of ruminant forage. Biodiversitas 24: ...6332-6342. Limestone post-mining land is a potential marginal land, through revegetation and integration, as a forage provider. Therefore, utilizing an exploratory systematic random sampling, this research explored the native botanical composition that had the potential for forage and soil microfauna associated with plants in the limestone post-mining land of PT Sinar Tambang Arthalestari, Banyumas, Central Java, Indonesia from June to September 2023. The results showed that the limestone post-mining soil had a slightly alkaline pH and low fertility. The botanical composition comprised 16 grasses, four legumes, and 21 forbs. Native plants that have the highest Importance Value Index (IVI) were grasses; Ischaemum rugosum, Imperata cylindrica, Paspalum scrobiculatum, and legumes; Mimosa pudica, Centrosema pubescens, and Calopogonium mucunoides. Grasses contained 8.35-12.61% Crude Protein (CP) and 42.50-50.78% Total Digestible Nutrient (TDN), while legumes contained 17.06-17.74% CP, 62.12-64.75% TDN. Mycorrhizal colonization and populations of Azotobacter, Azospirilum, and Rhizobium were associated with native plants in the rhizosphere. Conclusively, the grasses I. rugosum, I. cylindrica, P. scrobiculatum, and the legumes M. pudica, C. pubescens, and C. mucunoides have the potential to forage on limestone post-mining land and are associated with soil microfauna. However, soil fertility requires further improvement by applying organic matter, nitrogen, and phosphorus fertilizers.
Loss of plant diversity with increased anthropogenic nitrogen (N) deposition in grasslands has occurred globally. In most cases, competitive exclusion driven by preemption of light or space is ...invoked as a key mechanism. Here, we provide evidence from a 9‐yr N‐addition experiment for an alternative mechanism: differential sensitivity of forbs and grasses to increased soil manganese (Mn) levels. In Inner Mongolia steppes, increasing the N supply shifted plant community composition from grass–forb codominance (primarily Stipa krylovii and Artemisia frigida, respectively) to exclusive dominance by grass, with associated declines in overall species richness. Reduced abundance of forbs was linked to soil acidification that increased mobilization of soil Mn, with a 10‐fold greater accumulation of Mn in forbs than in grasses. The enhanced accumulation of Mn in forbs was correlated with reduced photosynthetic rates and growth, and is consistent with the loss of forb species. Differential accumulation of Mn between forbs and grasses can be linked to fundamental differences between dicots and monocots in the biochemical pathways regulating metal transport. These findings provide a mechanistic explanation for N‐induced species loss in temperate grasslands by linking metal mobilization in soil to differential metal acquisition and impacts on key functional groups in these ecosystems.
The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making ...the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO₂), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO₂had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid‐dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens.
PDF
