Species replacement and transitional zones in natural grasslands with subtle environmental gradations

2021 ◽  
Author(s):  
Natalia Vercelli ◽  
Ilda Entraigas
2021 ◽  
Vol 13 (6) ◽  
pp. 3569
Author(s):  
Hua Cheng ◽  
Baocheng Jin ◽  
Kai Luo ◽  
Jiuying Pei ◽  
Xueli Zhang ◽  
...  

Quantitatively estimating the grazing intensity (GI) effects on vegetation in semiarid hilly grassland of the Loess Plateau can help to develop safe utilization levels for natural grasslands, which is a necessity of maintaining livestock production and sustainable development of grasslands. Normalized difference vegetation index (NDVI), field vegetation data, and 181 days (one goat per day) of GPS tracking were combined to quantify the spatial pattern of GI, and its effects on the vegetation community structure. The spatial distribution of GI was uneven, with a mean value of 0.50 goats/ha, and 95% of the study area had less than 1.30 goats/ha. The areas with utilization rates of rangeland (July) lower than 45% and 20% made up about 95% and 60% of the study area, respectively. Grazing significantly reduced monthly aboveground biomass, but the grazing effects on plant growth rate were complex across the different plant growth stages. Grazing impaired plant growth in general, but the intermediate GI appeared to facilitate plant growth rate at the end of the growing seasons. Grazing had minimal relationship with vegetation community structure characteristics, though Importance Value of forbs increased with increasing GI. Flexibility in the number of goats and conservatively defining utilization rate, according to the inter-annual variation of utilization biomass, would be beneficial to achieve ecologically healthy and economically sustainable GI.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sergei Schaub ◽  
Robert Finger ◽  
Florian Leiber ◽  
Stefan Probst ◽  
Michael Kreuzer ◽  
...  

2020 ◽  
Vol 12 (17) ◽  
pp. 2760
Author(s):  
Gourav Misra ◽  
Fiona Cawkwell ◽  
Astrid Wingler

Remote sensing of plant phenology as an indicator of climate change and for mapping land cover has received significant scientific interest in the past two decades. The advancing of spring events, the lengthening of the growing season, the shifting of tree lines, the decreasing sensitivity to warming and the uniformity of spring across elevations are a few of the important indicators of trends in phenology. The Sentinel-2 satellite sensors launched in June 2015 (A) and March 2017 (B), with their high temporal frequency and spatial resolution for improved land mapping missions, have contributed significantly to knowledge on vegetation over the last three years. However, despite the additional red-edge and short wave infra-red (SWIR) bands available on the Sentinel-2 multispectral instruments, with improved vegetation species detection capabilities, there has been very little research on their efficacy to track vegetation cover and its phenology. For example, out of approximately every four papers that analyse normalised difference vegetation index (NDVI) or enhanced vegetation index (EVI) derived from Sentinel-2 imagery, only one mentions either SWIR or the red-edge bands. Despite the short duration that the Sentinel-2 platforms have been operational, they have proved their potential in a wide range of phenological studies of crops, forests, natural grasslands, and other vegetated areas, and in particular through fusion of the data with those from other sensors, e.g., Sentinel-1, Landsat and MODIS. This review paper discusses the current state of vegetation phenology studies based on the first five years of Sentinel-2, their advantages, limitations, and the scope for future developments.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1540
Author(s):  
Bence Fülöp ◽  
Bálint Pacsai ◽  
Judit Bódis

Semi-natural grasslands were previously established through traditional land use and maintained by active management, but their extension nowadays is declining rapidly, particularly in areas that also have tourism potential. In parallel, the conservation value of the remaining areas is increasing. The shore of Lake Balaton is a particularly good example, as Lake Balaton is an area highly affected by tourism, yet there have been valuable habitats able to survive and provide refuge for many vulnerable, protected species. Fortunately, we have reliable information about the vegetation of the area from two decades ago. Comparing these data with our recent surveys we investigated the changes in habitats and the distribution of protected plant species in connection with the active conservation treatments such as grazing or cutting. Our results show that in areas where treatments are still ongoing, protected plant species are more likely to survive, or even other species can appear, which is in clear contrast with conditions experienced in abandoned areas, where at least seven protected species have disappeared. According to our results, minor, but appropriately chosen and well-executed management interventions, can help in the long-term maintenance of species-rich habitats and improving the conservation status of threatened species.


Zootaxa ◽  
2020 ◽  
Vol 4830 (3) ◽  
pp. 503-543
Author(s):  
ADALBERTO DANTAS DE MEDEIROS ◽  
DIEGO RODRIGO DOLIBAINA ◽  
EDUARDO CARNEIRO ◽  
OLAF HERMANN HENDRIK MIELKE ◽  
MIRNA MARTINS CASAGRANDE

The South American genus Panca Evans, 1955 and its respective species are revised. Previous to this study, the genus included solely its type species, Lerodea subpunctuli Hayward, 1934, until Panca moseri Dolibaina, Carneiro & O. Mielke, 2017 was described recently. However, as a result of a broader morphological study including closely related genera, we here propose that Panca assembles 12 species, most of which inhabit open environments such as the Cerrado biome and the natural grasslands of the Atlantic Forest biome. Eight species formerly included among other genera of Moncina are here combined with Panca: Panca satyr (Evans, 1955) comb. nov., Panca tobiasi (Mielke, 1992) comb. nov., Panca trogon (Evans, 1955) comb. nov., Panca steinhauseri (Dolibaina & A. Warren, 2015) comb. nov., Panca acroleuca (Plötz, 1884) comb. nov., and Panca mirnae (O. Mielke, Dolibaina, Carneiro & A. Warren, 2015) comb. nov. (all formerly in Artines Godman, 1901), Panca paulo (Bell, 1932) comb. nov. (formerly in Eutocus Godman, 1901), and Panca mictra (Evans, 1955) comb. nov. (formerly in Vidius Evans, 1955). Additionally, two new species are described from Brazil: Panca puri Medeiros, O. Mielke & Casagrande sp. nov. (from Pará, Pernambuco, Minas Gerais, Rio de Janeiro and Paraná) and Panca xavante Medeiros, O. Mielke & Dolibaina sp. nov. (from Mato Grosso, Goiás, Distrito Federal and Minas Gerais). A neotype for Apaustus acroleuca Plötz, 1884 is designated. Illustrations of the male and female genitalia and distribution maps are presented for all the species of Panca and an identification key is provided for both sexes. 


2016 ◽  
Vol 37 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Dániel Kovács ◽  
István Kiss

Although Ablepharus kitaibelii and its subspecies are wide-spread, being distributed from the Carpathian Basin through the Balkans to Iraq, their habitat and environmental niche is poorly known. Ablepharus kitaibelii fitzingeri is almost entirely limited to the Carpathian Basin, and is amongst the most strictly protected and least known reptiles of Central and Eastern Europe. The main aim of our study was to determine habitat use preferences of different age groups of A. kitaibelii fitzingeri and Lacerta viridis. The occurrence of green lizard was determined by the abundance of refugia rather than by the naturalness of grasslands. The snake-eyed skink prefers semi-natural grasslands with abundant tussock-forming grass or sedge species, avoiding densely shrubby places. For the first time, we show that woodland mosaics lacking shrubs and temporary grasslands next to forest edges are important for the species. Microhabitat use by snake-eyed skink varies with age group; adults preferring shady edge zones rich in leaf litter and shadier grassland spots provided by woodland mosaics, whereas juveniles were found in natural, more open grasslands far from forest edges and in woodland mosaics with dense shrubby understory. Our results contribute to a better understanding of the ecological needs of A. kitaibelii fitzingeri. Our methodology could be adapted to other species and subspecies of Ablepharus. Based on our results, it is important to reconsider habitat management activities, which should not be limited to shrub control: the main goal should be the development of a diverse habitat structure.


2021 ◽  
Vol 13 (14) ◽  
pp. 2649
Author(s):  
Hafiz Ali Imran ◽  
Damiano Gianelle ◽  
Michele Scotton ◽  
Duccio Rocchini ◽  
Michele Dalponte ◽  
...  

Plant biodiversity is an important feature of grassland ecosystems, as it is related to the provision of many ecosystem services crucial for the human economy and well-being. Given the importance of grasslands, research has been carried out in recent years on the potential to monitor them with novel remote sensing techniques. In this study, the optical diversity (also called spectral diversity) approach was adopted to check the potential of using high-resolution hyperspectral images to estimate α-diversity in grassland ecosystems. In 2018 and 2019, grassland species composition was surveyed and canopy hyperspectral data were acquired at two grassland sites: Monte Bondone (IT-MBo; species-rich semi-natural grasslands) and an experimental farm of the University of Padova, Legnaro, Padua, Italy (IT-PD; artificially established grassland plots with a species-poor mixture). The relationship between biodiversity (species richness, Shannon’s, species evenness, and Simpson’s indices) and optical diversity metrics (coefficient of variation-CV and standard deviation-SD) was not consistent across the investigated grassland plant communities. Species richness could be estimated by optical diversity metrics with an R = 0.87 at the IT-PD species-poor site. In the more complex and species-rich grasslands at IT-MBo, the estimation of biodiversity indices was more difficult and the optical diversity metrics failed to estimate biodiversity as accurately as in IT-PD probably due to the higher number of species and the strong canopy spatial heterogeneity. Therefore, the results of the study confirmed the ability of spectral proxies to detect grassland α-diversity in man-made grassland ecosystems but highlighted the limitations of the spectral diversity approach to estimate biodiversity when natural grasslands are observed. Nevertheless, at IT-MBo, the optical diversity metric SD calculated from post-processed hyperspectral images and transformed spectra showed, in the red part of the spectrum, a significant correlation (up to R = 0.56, p = 0.004) with biodiversity indices. Spatial resampling highlighted that for the IT-PD sward the optimal optical pixel size was 1 cm, while for the IT-MBo natural grassland it was 1 mm. The random pixel extraction did not improve the performance of the optical diversity metrics at both study sites. Further research is needed to fully understand the links between α-diversity and spectral and biochemical heterogeneity in complex heterogeneous ecosystems, and to assess whether the optical diversity approach can be adopted at the spatial scale to detect β-diversity. Such insights will provide more robust information on the mechanisms linking grassland diversity and optical heterogeneity.


2004 ◽  
Vol 51 (4) ◽  
pp. 351-368 ◽  
Author(s):  
M.H. Bruinenberg ◽  
A.H. Van Gelder ◽  
P. Gonzalez Perez ◽  
V.A. Hindle ◽  
J.W. Cone

2017 ◽  
Vol 215 (2) ◽  
pp. 756-765 ◽  
Author(s):  
Teng Yang ◽  
Jonathan M. Adams ◽  
Yu Shi ◽  
Jin-sheng He ◽  
Xin Jing ◽  
...  

2013 ◽  
Vol 101 (5) ◽  
pp. 1237-1244 ◽  
Author(s):  
Francesco de Bello ◽  
Marie Vandewalle ◽  
Triin Reitalu ◽  
Jan Lepš ◽  
Honor C. Prentice ◽  
...  
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