scholarly journals Climate and grazing control nurse effects in an Ecuadorian dry shrubby community

2013 ◽  
Vol 30 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Carlos Iván Espinosa ◽  
Arantzazu L. Luzuriaga ◽  
Marcelino de la Cruz ◽  
Adrián Escudero
Keyword(s):  
Species Richness ◽  
Plant Community ◽  
Spatial Scales ◽  
Plant Cover ◽  
Grazing Intensity ◽  
Joint Effect ◽  
Plant Interactions ◽  
Opposite Trend ◽  
Nurse Effect ◽  
Nurse Effects

Abstract:Positive plant interactions have strong effects on plant diversity at several spatial scales, expanding species distribution under stressful conditions. We evaluated the joint effect of climate and grazing on the nurse effect of Croton wagneri, by monitoring several community attributes at two spatial scales: microhabitat and plant community. Two very close locations that only differed in grazing intensity were surveyed in an Ecuadorian dry scrub ecosystem. At each location, two 30 × 30-m plots were established at four altitudinal levels (1500, 2630, 1959 and 2100 m asl) and 40 microsites were surveyed in each plot. Croton wagneri acted as community hubs, increasing species richness and plant cover at both scales. Beneath nurses mean richness and cover values were 3.4 and 21.9%, and in open areas 2.3 and 4.5%, respectively. Magnitude of nurse effect was dependent on climate and grazing conditions. In ungrazed locations, cover increased and diversity reduced with altitude, while grazed locations showed the opposite trend. In ungrazed plots the interactions shifted from positive to negative with altitude, in grazed locations interactions remained positive. We conclude that the nurse effect is a key mechanism regulating community properties not only at microsite but also at the entire community scale.

scholarly journals Soil Properties and Plant Community Changes along a Goat Grazing Intensity Gradient in an Open Canopy Oak Forest

2013 ◽  
Vol 41 (2) ◽  
pp. 567 ◽  
Author(s):  
Aimilia LEMPESI ◽  
Apostolos P. KYRIAZOPOULOS ◽  
Michail ORFANOUDAKIS ◽  
Georgios KORAKIS
Keyword(s):  
Soil Properties ◽  
Plant Community ◽  
Management Practices ◽  
Plant Cover ◽  
Grazing Intensity ◽  
Oak Forest ◽  
Goat Grazing ◽  
Open Canopy ◽  
Grazing Intensities ◽  
Soil Measurements

Understanding how the management practices of silvopastoral systems affect the long-term sustainability of oak ecosystems and what their influence is on nutrient cycling and plant community, is of great interest. The aim of this study was to examine the effects of relative grazing intensity on soil properties and on vegetation characteristics in an open canopy oak forest dominated by Quercus frainetto. The research was conducted in the area of Pentalofos, which is located in Evros region, north-eastern Greece and is grazed by goats. The distance from a goat corral was used to represent relative grazing intensity. In June 2011, soil and vegetation samples were collected along transects placed at 50, 150, 300, 600 and 1200 m from the goat corral, running perpendicular to three replicates. Soil measurements included pH, phosphorous (P) and nitrogen (N) concentrations while vegetation measurements included plant cover, species composition and diversity. Plant cover was not significantly different among grazing intensities. Species diversity, especially of the woody vegetation layer, was significantly higher in the light grazing intensity in comparison to both the heavy and the very light grazing. Heavy grazing reduced soil organic matter while it increased total nitrogen. Grazing intensity did not affect available P and soil pH. Light to moderate goat grazing could ameliorate floristic diversity and increase sustainability of oak forests in the Mediterranean region.

scholarly journals Complex community responses underpin biodiversity change following invasion

2021 ◽  
Author(s):  
Alessandra R. Kortz ◽  
Anne E. Magurran
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Spatial Scales ◽  
Species Abundance ◽  
Ecological Systems ◽  
Multi Scale ◽  
Mechanistic Approach ◽  
Α Diversity ◽  
Biodiversity Change ◽  
Insight Into

AbstractHow do invasive species change native biodiversity? One reason why this long-standing question remains challenging to answer could be because the main focus of the invasion literature has been on shifts in species richness (a measure of α-diversity). As the underlying components of community structure—intraspecific aggregation, interspecific density and the species abundance distribution (SAD)—are potentially impacted in different ways during invasion, trends in species richness provide only limited insight into the mechanisms leading to biodiversity change. In addition, these impacts can be manifested in distinct ways at different spatial scales. Here we take advantage of the new Measurement of Biodiversity (MoB) framework to reanalyse data collected in an invasion front in the Brazilian Cerrado biodiversity hotspot. We show that, by using the MoB multi-scale approach, we are able to link reductions in species richness in invaded sites to restructuring in the SAD. This restructuring takes the form of lower evenness in sites invaded by pines relative to sites without pines. Shifts in aggregation also occur. There is a clear signature of spatial scale in biodiversity change linked to the presence of an invasive species. These results demonstrate how the MoB approach can play an important role in helping invasion ecologists, field biologists and conservation managers move towards a more mechanistic approach to detecting and interpreting changes in ecological systems following invasion.

scholarly journals Plant community composition and species richness in the High Arctic tundra: From the present to the future

2017 ◽  
Vol 7 (23) ◽  
pp. 10233-10242 ◽  
Author(s):  
Jacob Nabe-Nielsen ◽  
Signe Normand ◽  
Francis K. C. Hui ◽  
Laerke Stewart ◽  
Christian Bay ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Plant Community ◽  
Arctic Tundra ◽  
High Arctic ◽  
Plant Community Composition ◽  
The Future

scholarly journals Altitudinal Vascular Plant Richness and Climate Change in the Alpine Zone of the Lefka Ori, Crete

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
George Kazakis ◽  
Dany Ghosn ◽  
Ilektra Remoundou ◽  
Panagiotis Nyktas ◽  
Michael A. Talias ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Spatial Scales ◽  
Vascular Plant ◽  
Monitoring Network ◽  
Mediterranean Area ◽  
Mean Annual Temperature ◽  
High Mountain ◽  
Species Loss ◽  
Total Species Richness

High mountain zones in the Mediterranean area are considered more vulnerable in comparison to lower altitudes zones. Lefka Ori massif, a global biodiversity hotspot on the island of Crete is part of the Global Observation Research Initiative in Alpine Environments (GLORIA) monitoring network. The paper examines species and vegetation changes with respect to climate and altitude over a seven-year period (2001–2008) at a range of spatial scales (10 m Summit Area Section-SAS, 5 m SAS, 1 m2) using the GLORIA protocol in a re-survey of four mountain summits (1664 m–2339 m). The absolute species loss between 2001–2008 was 4, among which were 2 endemics. At the scale of individual summits, the highest changes were recorded at the lower summits with absolute species loss 4 in both cases. Paired t-tests for the total species richness at 1 m2 between 2001–2008, showed no significant differences. No significant differences were found at the individual summit level neither at the 5 m SAS or the 10 m SAS. Time series analysis reveals that soil mean annual temperature is increasing at all summits. Linear regressions with the climatic variables show a positive effect on species richness at the 5 m and 10 m SAS as well as species changes at the 5 m SAS. In particular, June mean temperature has the highest predictive power for species changes at the 5 m SAS. Recorded changes in species richness point more towards fluctuations within a plant community’s normal range, although there seem to be more significant diversity changes in higher summits related to aspects. Our work provides additional evidence to assess the effects of climate change on plant diversity in Mediterranean mountains and particularly those of islands which remain understudied.

scholarly journals Body size, reef area and temperature predict global reef-fish species richness across spatial scales

2018 ◽  
Vol 28 (3) ◽  
pp. 315-327 ◽  
Author(s):  
D. R. Barneche ◽  
E. L. Rezende ◽  
V. Parravicini ◽  
E. Maire ◽  
G. J. Edgar ◽  
...  
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Reef Fish ◽  
Fish Species ◽  
Spatial Scales ◽  
Reef Area ◽  
Reef Fish Species

scholarly journals The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants

2011 ◽  
Vol 366 (1582) ◽  
pp. 3256-3264 ◽  
Author(s):  
Paul Woodcock ◽  
David P. Edwards ◽  
Tom M. Fayle ◽  
Rob J. Newton ◽  
Chey Vun Khen ◽  
...  
Keyword(s):  
Species Richness ◽  
Leaf Litter ◽  
Oil Palm ◽  
Species Turnover ◽  
Spatial Scales ◽  
Forest Conversion ◽  
Conservation Value ◽  
Natural Forests ◽  
Ant Communities ◽  
Logged Forest

South East Asia is widely regarded as a centre of threatened biodiversity owing to extensive logging and forest conversion to agriculture. In particular, forests degraded by repeated rounds of intensive logging are viewed as having little conservation value and are afforded meagre protection from conversion to oil palm. Here, we determine the biological value of such heavily degraded forests by comparing leaf-litter ant communities in unlogged (natural) and twice-logged forests in Sabah, Borneo. We accounted for impacts of logging on habitat heterogeneity by comparing species richness and composition at four nested spatial scales, and examining how species richness was partitioned across the landscape in each habitat. We found that twice-logged forest had fewer species occurrences, lower species richness at small spatial scales and altered species composition compared with natural forests. However, over 80 per cent of species found in unlogged forest were detected within twice-logged forest. Moreover, greater species turnover among sites in twice-logged forest resulted in identical species richness between habitats at the largest spatial scale. While two intensive logging cycles have negative impacts on ant communities, these degraded forests clearly provide important habitat for numerous species and preventing their conversion to oil palm and other crops should be a conservation priority.

scholarly journals The pitfalls of biodiversity proxies: Differences in richness patterns of birds, trees and understudied diversity across Amazonia

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Camila D. Ritter ◽  
Søren Faurby ◽  
Dominic J. Bennett ◽  
Luciano N. Naka ◽  
Hans ter Steege ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Spatial Scales ◽  
Local Environment ◽  
Life Forms ◽  
Taxonomic Group ◽  
Diversity Gradients ◽  
Richness Patterns ◽  
Taxonomic Groups ◽  
Micro Organisms

AbstractMost knowledge on biodiversity derives from the study of charismatic macro-organisms, such as birds and trees. However, the diversity of micro-organisms constitutes the majority of all life forms on Earth. Here, we ask if the patterns of richness inferred for macro-organisms are similar for micro-organisms. For this, we barcoded samples of soil, litter and insects from four localities on a west-to-east transect across Amazonia. We quantified richness as Operational Taxonomic Units (OTUs) in those samples using three molecular markers. We then compared OTU richness with species richness of two relatively well-studied organism groups in Amazonia: trees and birds. We find that OTU richness shows a declining west-to-east diversity gradient that is in agreement with the species richness patterns documented here and previously for birds and trees. These results suggest that most taxonomic groups respond to the same overall diversity gradients at large spatial scales. However, our results show a different pattern of richness in relation to habitat types, suggesting that the idiosyncrasies of each taxonomic group and peculiarities of the local environment frequently override large-scale diversity gradients. Our findings caution against using the diversity distribution of one taxonomic group as an indication of patterns of richness across all groups.

scholarly journals Climate and plant community diversity in space and time

2020 ◽  
Vol 117 (9) ◽  
pp. 4464-4470 ◽  
Author(s):  
Susan Harrison ◽  
Marko J. Spasojevic ◽  
Daijiang Li
Keyword(s):  
Plant Community ◽  
Plant Diversity ◽  
Phylogenetic Diversity ◽  
Spatial Scales ◽  
Community Diversity ◽  
Niche Conservatism ◽  
Space And Time ◽  
Drying Trend ◽  
Functional And Phylogenetic Diversity ◽  
Over Time

Climate strongly shapes plant diversity over large spatial scales, with relatively warm and wet (benign, productive) regions supporting greater numbers of species. Unresolved aspects of this relationship include what causes it, whether it permeates to community diversity at smaller spatial scales, whether it is accompanied by patterns in functional and phylogenetic diversity as some hypotheses predict, and whether it is paralleled by climate-driven changes in diversity over time. Here, studies of Californian plants are reviewed and new analyses are conducted to synthesize climate–diversity relationships in space and time. Across spatial scales and organizational levels, plant diversity is maximized in more productive (wetter) climates, and these consistent spatial relationships are mirrored in losses of taxonomic, functional, and phylogenetic diversity over time during a recent climatic drying trend. These results support the tolerance and climatic niche conservatism hypotheses for climate–diversity relationships, and suggest there is some predictability to future changes in diversity in water-limited climates.

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