Plant Species Composition Of Grasslands Research Articles

An analysis of plant palatability on pastures of the delta: Case study, Danube Delta area, Romania

The palatability of a plant refers to the degree of attraction or preference that animals show toward that particular plant. Various factors can influence palatability, including the plant’s chemical composition, texture, taste, aromas, and the circumstances under which herbivorous animals consume it. The study aims to assess the plant species composition in grasslands and pastures within the Danube Delta, Romania. Both old or new references on palatability were considered. The evaluation of plant composition and degree of plant palatability was carried out in 12 grazing areas in the Danube Delta and the surrounding region. The study revealed 121 plant species identified in some pastures. Of these, 31 were “Non-Palatable”, 16 were “Highly Palatable”, 32 were “Mostly Palatable”, 16 were “Less Palatable”, and 26 were “Rarely Palatable”. Animals preferred 60 plant species in their fresh condition, with 29 preferred in fresh and dry. Most animals consumed whole plants (48 species), followed by leaves (43 species), fruits (three species), and inflorescences (two species). By analysing the feeding preferences of animals, it was found that cows exhibited a preference for the broadest range of plants (75 species), followed by sheep (67 species), goats (59 species), and horses (34 species). Domestic animals like goats, sheep, cows, and horses may prefer certain plants based on nutritional content or digestibility while avoiding toxic plants. The study showed that the investigated areas have a diverse flora with a varied supply of plants, including palatable species. The palatability index is essential in assessing the quality of pastures, especially in obtaining average daily gains based on the species of animals living on the pastures. Considering the dynamic climatic conditions and poor pasture quality in the Danube Delta, more detailed and interdisciplinary studies are needed to understand the deltaic biocenoses comprehensively.

Collaborative Adaptive Rangeland Management, Multipaddock Rotational Grazing, and the Story of the Regrazed Grass Plant

Frequent, severe defoliation reduces grass production and can alter plant species composition in grasslands. Multipaddock rotational grazing has been proposed as a grazing strategy that may reduce the frequency and intensity of defoliation on palatable grass plants without altering stocking rates. Previous studies evaluated this hypothesis using small, homogeneous paddocks and nonadaptive rotation schedules and found small and inconsistent differences between continuous and rotational grazing systems. Using a stakeholder-driven collaborative adaptive management (CAM) framework, we conducted the first ranch-scale experimental investigation into tiller defoliation patterns in the context of adaptive multipaddock rotational grazing. We monitored tiller defoliation frequency and intensity in 10 paired 130-ha pastures assigned to either a collaborative adaptive multipaddock rotational grazing treatment (CARM, one livestock herd) or a season-long continuous grazing treatment (traditional rangeland management [TRM]; 10 separate herds) in shortgrass steppe. Consistent with previous studies, we observed that frequencies of grazing and regrazing on a palatable, cool-season grass (western wheatgrass, Pascopyrum smithii) were much more sensitive to stocking rate than grazing system. Under moderate stocking rates used in both CARM and TRM treatments, roughly two-thirds of western wheatgrass tillers remained ungrazed annually, regardless of grazing system. Thus, season-long rest is present in season-long continuous and rotational grazing systems. Frequencies of tiller regrazing were low (5−15%) and similar between CARM and TRM treatments. Although defoliation patterns were similar between treatments at the whole-ranch scale, CARM enhanced spatial and temporal heterogeneity in defoliation frequencies among individual pastures. Pastures grazed earlier in the season or for longer experienced more defoliation. Managers implementing adaptive, multipaddock rotational grazing could use this heightened and predictable variability to strategically manage impacts of grazing on western wheatgrass at the individual pasture scale. The CAM model enabled our team to identify and directly address key stakeholder hypotheses and resulted in coproduction of management-relevant research.

Re‐visiting historical semi‐natural grasslands in the Apennines to assess patterns of changes in species composition and functional traits

AbstractQuestionsTo what extent have semi‐natural grassland plant species composition and functional traits changed during the past five decades? Which are the main directions of change? Which environmental, management and landscape factors have determined these changes?LocationCentral and southern Apennines of Italy.MethodsIn 2013–2014, we used a stratified random sampling design to revisit 132 semi‐natural grasslands originally sampled between 1966 and 1992. The exact locations of the historical plots were not available but they were associated with detailed vegetation maps. Plots were divided in 17 groups based on study area and original community type. To assess changes in species composition we ran PERMANOVA and RDA. The extent of change was estimated by comparing each new plot with the quantitative species pool of the corresponding historical group; species composition changes were calculated using Bray‐Curtis coefficient, and shifts in functional traits were quantified as differences in community‐weighted means. These measures of change were used as response variables in mixed effects models including climate, topography, management and landscape metrics as explanatory variables.ResultsThe largest changes were related to successional dynamics, which occurred mainly in grasslands developing at low altitude and in the flattest sites where the soil organic horizon was relatively thick. Colonization by shrubs and trees was facilitated by high soil pH and amount of adjacent forests. Also, management factors affected the patterns of shifts in species composition and functional traits: grazing intensity was negatively related to the degree of compositional change as well as to the abundance of woody species, whereas the increase of species associated with frequent grazing disturbance was found at sites with higher values of soil salinity.ConclusionsApennine semi‐natural grasslands have undergone substantial changes in species composition and functional traits during recent decades. Compositional changes mainly indicated successional dynamics, likely following a decrease in grazing intensity, whereas some more accessible grasslands experienced an increase in disturbance‐tolerant species. The combination of the re‐visitation approach with functional traits allowed us to clarify different directions of changes in species composition, adding information on the ecological processes related to these changes.

A continent‐wide study reveals clear relationships between regional abiotic conditions and post‐dispersal seed predation

AbstractAimLarge‐scale patterns linking energy availability, biological productivity and diversity form a central focus of ecology. Despite evidence that the activity and abundance of animals may be limited by climatic variables associated with regional biological productivity (e.g. mean annual precipitation and annual actual evapotranspiration), it is unclear whether plant–granivore interactions are themselves influenced by these climatic factors across broad spatial extents. We evaluated whether climatic conditions that are known to alter the abundance and activity of granivorous animals also affect rates of seed removal.LocationEleven sites across temperate North America.MethodsWe used a common protocol to assess the removal of the same seed species (Avena sativa) over a 2‐day period. Model selection via the Akaike information criterion was used to determine a set of candidate binomial generalized linear mixed models that evaluated the relationship between local climatic data and post‐dispersal seed predation.ResultsAnnual actual evapotranspiration was the single best predictor of the proportion of seeds removed. Annual actual evapotranspiration and mean annual precipitation were both positively related to mean seed removal and were included in four and three of the top five models, respectively. Annual temperature range was also positively related to seed removal and was an explanatory variable in three of the top four models.Main conclusionsOur work provides the first evidence that energy and precipitation, which are known to affect consumer abundance and activity, also translate to strong, predictable patterns of seed predation across a continent. More generally, these findings suggest that future changes in temperature and precipitation could have widespread consequences for plant species composition in grasslands, through impacts on plant recruitment.

Symposium 9: Rocky Mountain Futures: Preserving, Utilizing, and Sustaining Rocky Mountain Ecosystems

Symposium 9: Rocky Mountain Futures: Preserving, Utilizing, and Sustaining Rocky Mountain Ecosystems

A Comparative Study of Plant Species Composition of Grasslands in Saiwa Swamp National Park and Kakamega Forest, Kenya

Kakamega forest is a tropical rain forest ecosystem while Saiwa Swamp National Park (SSNP) is a riverine ecosystem. A study was conducted to determine plant species diversity of the grasslands in b...