Vascular plant and epiphytic lichen communities in Canadian aspen parkland: determinants of small-scale species richness

2002 ◽  
Vol 3 (1) ◽  
pp. 69-78 ◽  
Author(s):  
H.L. Buckley
2021 ◽  
Vol 53 (1) ◽  
pp. 149-158
Author(s):  
Robert J. Smith ◽  
Sarah Jovan ◽  
Susan Will-Wolf

AbstractLichens occupy diverse substrates across tremendous ranges of environmental variation. In boreal forests, lichen communities co-occur in ‘strata’ defined by terrestrial or arboreal substrates, but these strata may or may not be interchangeable as bioindicators. Do co-occurring lichen strata have similar community structures and environmental responses? Could one stratum serve as a proxy for the other? We assessed variation in species richness and community compositions between ground-layer versus epiphyte-layer lichen strata in boreal forests and peatlands of interior Alaska. Species richness was lower and more spatially structured in the ground layer than the epiphyte layer. Richness of strata was not correlated. The most compositionally unique ground-layer communities were species-poor but contained regionally rare species not common in other plots. Variation in community compositions (ordination scores) were not congruent between strata (Procrustes congruence < 0.16 on 0–1 scale); the largest departures from congruence occurred where ground layers were species-poor. The best predictors of ground-layer community compositions were hydrological and topographic, whereas epiphytes were most associated with macroclimate and tree abundances. We conclude that lichens on different substrates ‘move in different circles’: compositional gradients did not agree and the environmental gradients most important to each lichen stratum were not the same. The conditions which strongly influence one vegetation stratum may have little bearing upon another. As global changes modify habitats, an incremental change in environment may lead community trajectories to diverge among lichen strata.


2021 ◽  
Author(s):  
Kaja Rola ◽  
Vítězslav Plášek ◽  
Katarzyna Rożek ◽  
Szymon Zubek

Abstract Aim Overstorey tree species influence both soil properties and microclimate conditions in the forest floor, which in turn can induce changes in ground bryophyte communities. The aim of the study was to investigate the effect of tree species identity and the most important habitat factors influencing understorey bryophytes. Methods We assessed the effect of 14 tree species and related habitat parameters, including soil parameters, vascular plant presence and light intensity on bryophytes in monospecific plots covered by nearly fifty-year-old trees in the Siemianice Experimental Forest (Poland). Results The canopy tree species determined bryophyte species richness and cover. The strongest differences were observed between plots with deciduous and coniferous trees. Soils with a more acidic pH and lower content of macronutrients supported larger bryophyte coverage. We also found a positive correlations between vascular plants and availability of light as well as bryophyte species richness. Conclusion Tree species identity and differences in habitat conditions in the forest floor lead to changes of ground bryophyte richness, cover and species composition. Consequently, the changes in the dominant tree species in the stand may result in significant repercussions on ground bryophyte communities. We indicated that the introduction of alien tree species, i.e. Quercus rubra, has an adverse effect on bryophyte communities and suggested that the selection of tree species that contribute to the community consistent with the potential natural vegetation is highly beneficial for maintaining ground bryophyte biodiversity.


Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
George Kazakis ◽  
Dany Ghosn ◽  
Ilektra Remoundou ◽  
Panagiotis Nyktas ◽  
Michael A. Talias ◽  
...  

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.


2021 ◽  
pp. 1-10
Author(s):  
Carlos M. Delgado-Martínez ◽  
Fredy Alvarado ◽  
Melanie Kolb ◽  
Eduardo Mendoza

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.


Biologia ◽  
2007 ◽  
Vol 62 (4) ◽  
Author(s):  
Bruno Baur ◽  
Cristina Cremene ◽  
Gheorghe Groza ◽  
Anatoli Schileyko ◽  
Anette Baur ◽  
...  

AbstractAlpine grasslands in the Southern Carpathian Mts, Romania, harbour an extraordinarily high diversity of plants and invertebrates, including Carpathic endemics. In the past decades, intensive sheep grazing has caused a dramatic decrease in biodiversity and even led to eroded soils at many places in the Carpathians. Because of limited food resources, sheep are increasingly forced to graze on steep slopes, which were formerly not grazed by livestock and are considered as local biodiversity hotspots. We examined species richness, abundance and number of endemic vascular plants and terrestrial gastropods on steep slopes that were either grazed by sheep or ungrazed by livestock in two areas of the Southern Carpathians. On calcareous soils in the Bucegi Mts, a total of 177 vascular plant and 19 gastropod species were recorded. Twelve plant species (6.8%) and three gastropod species (15.8%) were endemic to the Carpathians. Grazed sites had lower plant and gastropod species richness than ungrazed sites. Furthermore, grazed sites harboured fewer gastropod species endemic to the Carpathians than ungrazed sites. On acid soils in the Fagaras Mts, a total of 96 vascular plant and nine gastropod species were found. In this mountain area, however, grazed and ungrazed sites did not differ in species richness, abundance and number of endemic plant and gastropod species. Our findings confirm the high biodiversity of grasslands on steep slopes in the Southern Carpathian Mts and caution against increasing grazing pressure in these refuges for relic plants and gastropods as well as for other invertebrates.


2018 ◽  
Vol 69 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Mari Tilk ◽  
Katri Ots ◽  
Tea Tullus ◽  
Malle Mandre

Abstract To investigate the ecosystems on dunes, five typical dunes were selected in the coastal area of the Baltic Sea in southwest Estonia. To study ground vegetation species richness, species composition and horizontal structure, 251 quadrats of 1 m2 in size were established and descriptions of vascular plants, bryophytes and lichen species were provided. Topographical factors, soil horizons, soil pH and electrical conductivity, soil nutrients, soil moisture conditions and light conditions were determined. In total, 42 vascular plant, 43 bryophyte and 48 lichen species were recorded on five dunes. Vascular plant species richness and composition on forested dunes was dependent on the absolute dune height, zone and aspect of the slope, soil nitrogen, potassium and phosphorus content, soil pH and moisture, the cover of the bryophyte-lichen layer and light conditions. Regarding bryophyte and lichen layer species composition, important factors were the aspect of the dune, vascular plant species cover, light conditions, the thickness of the moderately decomposed organic soil horizon, soil pH, electrical conductivity and volumetric water content. Lichen species richness was highest on the slopes of the dunes, while bryophyte species richness was higher at the bottoms and decreased towards the tops of the dunes. Ground vegetation species richness and species’ horizontal and vertical structure on forested dunes were highly dependent on topography-induced differences, aspect, height and zone of the dunes. The most important factors controlling the complex of ground vegetation were light conditions, soil water content, thickness of the moderately decomposed litter layer and soil potassium and calcium content.


2021 ◽  
Vol 9 (1) ◽  
pp. 32-35
Author(s):  
Lal awmpuia ◽  
◽  
H. Lalruatsanga ◽  

A survey of plant species inhabiting oil palm trees was conducted in Zawlpui area of Serchhip district, Mizoram. The study area is a tropical potent agriculture zone, wherein small-scale business of Elaeis guineensis plantation is carried out by several farmers mainly within the gentle sloppy terrain. Oil palm with a rough bark harbors immense inhabitation by a variety plants, that rooted mostly on the debris at leaf base. Species diversity on the plant stem supposedly encourage insects and termites to establish herewith, thus causing harming to the tree. The sample stands within 400 m–800 m altitude were picked randomly. A total of 50 palm tree were accounted and all associated plants on the stem above 30 cm from the ground are all recorded. Species that cannot be identified on the site were pressed and observed at Botany Research lab, Pachhunga University College. The survey documented 38 vascular plant species which include 4 epiphytes and 1 non-vascular species of lichen, 1 bryophyte and 4 fungal species at that time. Invasive Peperomia pellucida and epiphytic pteridophytes Nephrolepis biserrata was found in most of the stand sample; however, Peperomia population decreases with the increasing elevation. Dynamics of inhabitant species diversity also correlate to location of tree. The study also established that diversity of inhabiting species was comparatively high on parts of the stem facing sunlight.


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