The expansive upland grasslands at the Chestnut. Grove Natural Area (CGNA) make this location ideal for observing bird species that are not commonly seen in . The information in this Grassland Ecosystems Background Paper was developed by the Grassland, grassland ecosystems and the species they support. Grasslands are one of Earth's major biomes and the native vegetation of up to. 40 % of Earth's terrestrial surface. Grasslands occur on every continent.
|Language:||English, Spanish, German|
|ePub File Size:||30.41 MB|
|PDF File Size:||12.47 MB|
|Distribution:||Free* [*Register to download]|
PDF | Glossary Convention on biological diversity The Convention was first enacted in June , Finally, in Asia, grassland ecosystems cover a huge area. Geography of grassland ecosystems. Article (PDF Available) in Progress in Physical Geography 7(1) · March with 3, Reads. DOI: /. These Grassland Ecosystem Guidelines are the culmination of collaborative effort to compile and synthesize knowledge on grassland ecosystems for planners.
Grassland ecology Abstract Increasing evidence suggests that community-level responses to human-induced biodiversity loss start with a decrease of interactions among communities and between them and their abiotic environment. The structural and functional consequences of such interaction losses are poorly understood and have rarely been tested in real-world systems. Here, we analysed how 5 years of progressive, size-selective exclusion of large, medium, and small vertebrates and invertebrates—a realistic scenario of human-induced defaunation—impacts the strength of relationships between above- and belowground communities and their abiotic environment hereafter ecosystem coupling and how this relates to ecosystem functionality in grasslands. Exclusion of all vertebrates results in the greatest level of ecosystem coupling, while the additional loss of invertebrates leads to poorly coupled ecosystems. Consumer-driven changes in ecosystem functionality are positively related to changes in ecosystem coupling. Our results highlight the importance of invertebrate communities for maintaining ecological coupling and functioning in an increasingly defaunated world. Introduction Rapid human-induced decline in global biodiversity across all trophic levels 1 , 2 , 3 , 4 , 5 , 6 reduces the ability of ecosystems to maintain key ecosystem functions 2 , 3 , 7.
However, only a few studies have investigated such responses in real-world ecosystems and under realistic scenarios of animal biodiversity loss 1 , 4 , 15 , Thus, relatively little is known about the consequences of defaunation for ecosystem coupling.
Moreover, defaunation often operates in a size-selective, non-random manner, with larger species disappearing before smaller-sized species 4 , Although vertebrates have been progressively excluded in the size-selective order in which they are expected to disappear 18 , 19 , 20 , 21 , we are not aware of any study that has considered how the progressive, size-based loss of different vertebrates and invertebrates affects the strength of ecosystem coupling.
In addition, it is not known how defaunation-induced changes in ecosystem coupling may affect ecosystem functioning. Stronger interactions among communities and between communities and their environment should lead to greater ecosystem functionality due to more efficient transfer of nutrients and energy through the system 22 , 23 , which should result in a greater ability to withstand environmental stress 7.
We carried out a 5-year field experiment in subalpine grasslands in which we progressively excluded large, medium and small mammalian vertebrates, and, ultimately, all aboveground-dwelling invertebrates with size-selective fences 24 , 25 Fig. Large mammals are often assumed to drive trophic interactions via top—down effects and impact other communities and abiotic properties via predation, grazing, resource competition or facilitation 26 , 27 , 28 , We therefore predicted that the loss of large animals would reduce ecosystem coupling more than a subsequent loss of smaller animals.
Expecting that stronger links between communities and between communities and their environment result in a more efficient flow of energy and matter through the ecosystem 22 , 23 , we also predicted a positive relationship between ecosystem coupling and functionality.
Nine exclosure setups were established in each of the two different vegetation types; short-grass and tall-grass vegetation. Data were collected on a total of 90 plots, from which we calculated ecosystem coupling and multifunctionality.
The photo in the background shows two of our 18 exclosure setups in the field. Martijn L.
Vandegehuchte created the animal and vegetation images for use in this paper. The animal images were adapted from Vandegehuchte et al. Anita C. Risch took the background photo and created the design image, Pablo Hueso composed the Figure Full size image The field experiment encompassed 18 size-selective exclosure setups distributed across two clearly differentiated vegetation types in the Swiss National Park SNP; nine in short-grass, nine in tall-grass vegetation; Fig.
Each exclosure setup contained four treatment plots that progressively excluded large, medium and small-sized mammals and aboveground-dwelling invertebrates 24 Fig. The grasslands under study can be considered natural, as humans have not directly disturbed the ecological processes within the SNP since protection status IUCN category Ia We calculated how our treatments affected ecosystem coupling using correlations between multivariate components [principal component analyses PCA axes scores] that represent the structure and composition of ecological communities as well as correlations between these components and the physicochemical environment 9.
As such, ecosystem coupling is a measure of how communities not species respond to alterations of the ecosystem 9 as happens through eutrophication, climate warming or species loss 1 , 4 , 32 , Ecosystem coupling can then be compared against a null model where the average correlation strength absolute value of pairwise Spearman rank correlations does not differ from random 22 , 34 , The greater the mean of absolute correlations, the more tightly coupled the ecosystem is.
We assessed how the progressive animal exclusions affected overall ecosystem coupling, i. Today these grasslands are considered the most altered terrestrial ecosystem on the planet and are recognized as the most endangered ecosystem on most continents. Only a small percentage 4. Temperate grasslands have been cradling the needs of humans for millennia however conversion for agriculture, fragmentation, development, and chronic overgrazing have severely degraded the natural ecosystem.
In response, the Grasslands Specialist Group launched the Temperate Grasslands Conservation Initiative TGCI in to develop a global strategy and regional approaches to improving the level of conservation and protection for this biome.
Kirk Olson has been selected to take over the role of Chair. Our Mission: To reverse the trend of biodiversity loss in the grasslands biome. We will achieve this mission by 1 identifying and creating new protected areas that conserve and protect areas of special importance for biodiversity, ecosystem services and sustainable use, consistent with the principles as outlined in Aichi Target 11; and 2 encouraging the development of policies that prevent conversion of grassland for agriculture and maintain permeability across open grasslands as outlined in Aichi Targets 5, and Our Objectives: Raise awareness about the need for increased conservation and protection of temperate grasslands.
Prairie dogs were observed building burrows and chewing ephedra at the edge of prairie dog colonies that were surrounded by shrublands. In one particular colony, mapped in 1, ha , the expansion was evident, so it was re-mapped in to document this expansion. To determine the impact of prairie dogs on ephedra shrubs, individual shrubs were examined along a transect at the edge of the colony where it was expanding, and along an adjacent transect extending 50 m away from the colony.
The height of each shrub was measured, and it was examined for presence or absence of prairie dog teeth signs, exposure of the roots by prairie dog burrows, and clipping of stems and branches.
Parallel transects were established, each separated by 40 m. To reduce the observer error in assigning burrows as active or inactive, or other biases of the method  , density estimates in onwards were based on maximum number of prairie dogs aboveground at any one time observed from 12 4.
The triangle method consisted of three triangles measuring m per side 4. The vortices of the triangles were 50 m from the observer, so by turning around, the observer could record the number of prairie dogs within each triangle every 10 minutes.
Comparison of grassland and shrubland vertebrate communities Vertebrate diversity in grasslands with prairie dog colonies and in mesquite shrubland was assessed by establishing 4 replicate plots in grassland habitat and 4 replicate plots in shrubland habitat within a mosaic of a ca. Ten field trips, covering all 4 seasons, were conducted for all vertebrate groups between November and June Table S3. While our previous studies have compared vertebrate diversity in prairie dog colonies and adjacent grasslands in this area between —  ,  ,  , the grassland without prairie dogs is a transient vegetation type.
It often is rapidly invaded by woody plants, mainly mesquite and ephedra, converting it into shrubland. Reptile and amphibian diversity was compared with pitfall traps . Each trap consisted of a standard 20 liter plastic bucket . The traps remained opened for three consecutive days in each sampling period. Each site was checked every morning or twice a day on extremely hot days.
Bird diversity was assessed with point count transects  from — in various colonies of the prairie dog complex including the 4 grassland study sites Figure 2 , Table S3 , and in — the transects were sampled in each of the 4 grassland and 4 shrubland sites.
In —, each transect was 2. Each transect had 10 point counts at m intervals point counts total . In —, each transect was 1.
Each transect had 5 point counts at m intervals point counts total. For all point counts, the radius was 50 m and sampling time was 5 minutes. In —, the sampling took place in two sites in a 15, ha colony and one ha colony Figure 2 , Table S3. In each site a grid was established in the interior of the colony, one at the edge, and one in the shrubland m from the edge of the colony.
In — the small mammal trapping grids were established in the 4 grassland and 4 shrubland sites Figure 2 , Table S3.
Traps were opened for two consecutive nights on each grid. The small mammal trapping grids established on the prairie dog colony grasslands in — were in a different location than those established in — to accommodate different sampling designs. Lagomorphs and carnivores were sampled along all available roads within the shrubland and prairie dog colony grassland study sites from — and — Figure 2 and Table S3. During each sighting, species were identified as either desert cottontail or black-tailed jackrabbit and the number of individuals was recorded.
Carnivore density was determined on the same road transects, taking the perpendicular distance and angle, with respect to the transect's center, for each carnivore sighted .
Data Analysis For data analysis of comparisons between vertebrate communities in the shrubland and grassland habitats, we used non-parametric statistics on all data sets, and data for each vertebrate group were pooled across seasons. Wilcoxon Two-Sample W tests were used to analyze differences in herpetofauna, birds, and small mammals between the grassland and shrubland habitats .
Separate analyses were then conducted for each vertebrate group to evaluate differences in total abundance, species richness, functional groups, trophic groups, and each species between the grassland and shrubland habitats.