scholarly journals Patterns of vegetation composition across levels of canopy disturbance in temperate forests of west Himalaya, India

2017 ◽  
Vol 45 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Subodh Airi ◽  
Ranbeer S. Rawal

AbstractThis study analyses the impacts of canopy disturbance on vegetation compositional attributes of two characteristic temperate forests (i.e., mixed broad-leaf and banj-oak forests) in west Himalayan part of India. Following the standard approaches, quantitative information on compositional attributes of forest vegetation was generated and analyzed. Considerable changes in these attributes were revealed across different levels of canopy disturbance in both forests. In particular, tree density and total basal area (TBA) exhibited significant decline from undegraded to degraded stands. Among others, seedling and sapling density of mixed broad-leaf forest was affected adversely by increased level of canopy disturbance. However, herb density in this forest increased significantly with increasing levels of disturbance; the same was not true for banj-oak forest. A significant decline in relative frequency and density of native herbaceous species was apparent towards degraded stands, implying that the disturbed sites in both forests created an opportunity for the establishment and proliferation of non-natives. However, with significant increase in relative density of non-native herbs, the degraded stands of banj-oak forest emerged as critically vulnerable to non-native proliferation. The patterns of tree size class distribution in both forests also exhibited certain trends across canopy disturbance, which suggested possible future changes in composition. In particular, the patterns of common tree associates (i.e., Myrica esculenta and Rhododendron arboreum) in banj-oak forest and Pinus roxburghii in mixed broad-leaf forest were indicative of likely compositional changes in near future. The study concludes that: (i) compositional attributes of both mixed broad-leaf and banj-oak forests were sensitive to increasing levels of canopy disturbance, (ii) mixed broad-leaf forest exhibited greater sensitivity to canopy disturbance at recruitment levels, (iii) increased canopy disturbance led to establishment and proliferation of non-native species in the herbaceous layer of both forests, and (iv) banj-oak forest exhibited high vulnerability to non-native proliferation at degraded stage.

2012 ◽  
Vol 72 (2) ◽  
pp. 337-341 ◽  
Author(s):  
GI. Cruz-Ruiz ◽  
D. Mondragón ◽  
A. Santos-Moreno

The presence of lizards in bromeliads has been widely documented. Nevertheless, the possibility of some type of preference or specificity among lizards for particular bromeliad species has not yet been investigated. Therefore, this study aims to document the presence of Abronia oaxacae in six species of tank bromeliads found in pine forests, pine-live oak forests, and live oak groves during both the rainy season and the dry season. Three adult individuals of Abronia oaxacae were collected; one in a Tillandsia violácea (pine-live oak forest), one in a T. calothyrsus (live oak grove), and one in a T. prodigiosa (live oak grove). All three specimens were collected in sampling efforts carried out during the dry season. The results of the present study suggest that A. oaxacae shows no preference for a single, specific bromeliad species, although it does have a certain preference for a few select species. The presence of A. oaxacae in bromeliads during the dry season could be related to the cooler, moister microhabitat that these plants represent.


2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.


Author(s):  
Māris Laiviņš ◽  
Agnese Priede ◽  
Dārta Kaupe ◽  
Andis Lazdiņš

Abstract The succession of semi-natural xeric calcareous grassland plant communities toward deciduous forest communities is poorly studied in Latvia. There is insufficient knowledge on the natural transformation of dry calcareous grasslands of Festuco-Brometea into thermophilous quasi-climax oak forest communities of Quercetea pubescentis that are very rare in Latvia. In this paper, a geobotanical study is presented that included studies of soils, tree age, spatial pattern of trees, vegetation composition of different succession stages, and analysis of environmental factors. The study was conducted in the Abava Valley, West Latvia, an area that is unique with species-rich xeric calcareous Festuco-Brometea grasslands, thermophilous oak forests dominated by Quercus robur, and intermediate secondary succession stages with young to medium-aged Juniperus communis and Pinus sylvestris formations.


2013 ◽  
pp. 27-55
Author(s):  
Rade Cvjeticanin ◽  
Olivera Kosanin ◽  
Milun Krstic ◽  
Marko Perovic ◽  
Marijana Novakovic-Vukovic

This research was carried out in natural stands of sessile oak (Quercus petraea agg. Ehrendorfer 1967) on Miroc mountain. Three comunities were investigated: Pure sessile oak forest (Quercetum montanum Cer. et Jov. 1953. s.l.), sessile oak-common hornbeam forest (Querco-Carpinetum moesiacum Rud. 1949. s.l.) and sessile oak-balkan beech forest (Querco-Fagetum Glis. 1971). Pure sessile oak forests are found on the following soils: dystric ranker and acid cambic soil on sandstone, dystric ranker and acid cambisols on phyllite, and acid cambic soil on schists. Sessile oak-hornbeam forests grow on sandstone, granite and schists. Sessile oak-beech forests are found on acid cambisol on phyllite and sandstone conglomerate. Various ecological conditions (exposition, slope, altitude, soil types and bedrock) on Mt Miroc caused the occurence of diverse sessile oak forest communities, while different states of these forest stands resulted from the implementation of management measures.


2021 ◽  
Vol 42 ◽  
pp. e70549
Author(s):  
Jordi Bou ◽  
Lluís Vilar

The sessile oak forests found on the northeast of the Iberian Peninsula are ascribed to the Lathyro-Quercetumpetraeae association and play a key role in understanding the ecology of this habitat, as this region represents its xeric limit. For this reason, we analysed the biodiversity patterns and current conservation status of the sessile oak forests in the region. To do so, we collected Braun-Blanquet inventories of 34 plots randomly distributed throughout the sessile oak forests. The results showed a relationship between the climatic conditions and the biodiversity variables. While the richness of the community increased with decreasing temperatures, the characteristic species found within the community decreased at these same temperatures. This result was due to the presence of most companion species in the cool zones at high elevations.Sessile oaks are found close to other communities, such as silver birches and Scot pine forests.On the other hand, in the warm areas at low elevations, the sessile oak community was more established, with plants typical of this type of forest. These slightly warmer zones with sessile oaks are very important in terms of conservation and more vulnerable to climate change and the thermophilization of the community, as has been studied. As such, protecting and managing these forests is key to conserving this community. Nevertheless, as current protection measures do not safeguard most of these forests, it is essential to define a conservation strategy to preserve them. Using the conservation status, we have established criteria to improve the conservation strategy for sessile oak forest on the NE Iberian Peninsula.


2019 ◽  
Vol 12 (5) ◽  
pp. 894-906
Author(s):  
Jordi Bou ◽  
Lluís Vilar

AbstractAimsOur aims were 3-fold: (i) to determine whether global change has altered the composition and structure of the plant community found in the sessile oak forests on the NE Iberian Peninsula over the last decades, (ii) to establish whether the decline in forest exploitation activities that has taken place since the mid-20th century has had any effect on the forests and (iii) to ascertain whether there is any evidence of impact from climate warming.MethodsWe assess changes in the plant community by comparing a current survey of sessile oak forest with a historical data set obtained from previous regional studies dating from 1962 to 1977. We analyse the regional changes in the community in terms of biodiversity variables, species composition and plant traits. Furthermore, plants traits such as plant life forms and chorological groups are used to discern any effects from land-use changes and climate warming on the plant community.Important FindingsThere has been a loss of diversity in the community and, in the hottest region, there is also a loss of species richness. The composition of the community suggests that, although significant changes have taken place over recent decades, these changes differ between regions as a result of the low impact global change has had in the western regions. For instance, while the tree canopy cover in the western sessile oak forests remains stable, the eastern sessile oak forests are still recovering from the former exploitation that led to a loss of their rich and abundant herbaceous stratum. In fact, the recovery process in the Catalan Pre-Coastal Range has constituted an increase in the Euro-Siberian plants typical to this community. Moreover, in the eastern forests, there is evidence that climate warming has impacted the thermophilization of the sessile oak forests found on the Coastal Range.


2018 ◽  
Vol 13 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Vijyeta Manral ◽  
Kirtika Padalia ◽  
Himani Karki

Plant diversity is essential for human survival and economic well-being and also for the ecosystem function and stability. The total number of accessible seedlings and saplings in a forest community indicates the regeneration status/potential of a species or a forest. In this study, composition, diversity and population structure of three different forests (Banj oak, Chir-pine and Mixed oak-pine) was assessed around Nainital town of Uttarakhand state. Species richness and diversity were maximum in Banj-oak forest (9 species and 1.970, respectively) and minimum in Chir-pine forest (4 species and 0.634, respectively). The total tree density ranged from 1670 (Chir pine forest) to 1830 ind.ha-1 (Mixed oak pine forest) and the total basal area ranged from 87.22 (Mixed oak pine forest) to 208.37 m2ha-1 (Banj oak forest). Population structure revealed dominancy of mature trees and less number of seedlings evidently indicated the poor regeneration across the forests type. Viability of seeds, disturbances brought by frequent fire incidence, erosion of soil and water, uncontrolled grazing by animals, lopping/cuttings of under canopy plant species by villagers for fuel and fodder are the possible causes of the poor regeneration of the forests.


2015 ◽  
Vol 10 (2) ◽  
pp. 494-499 ◽  
Author(s):  
Kiran Bargali ◽  
S. S Bargali

In this paper, growth and storage of carbon and nitrogen in seedlings of banj oak (Quercus leucotrichophora A. Camus) and chir pine (Pinus roxburghii Sarg.) have been compared across different levels of nutrient and water availabilities. Four nutrient (144, 264, 384 and 504 mg of NPK fertilizer per kg soil) and three watering (21 days,14 days and 7 days interval) treatments were applied to seedlings. At low watering levels, seedling dry mass of both the species decreased towards higher nutrient level. However, at high watering level, dry mass increased with increasing water availability. When water availability was increased in a constant nutrient environment, dry mass of seedling increased with increase in water availability. Both the species showed a similar pattern of storing nitrogen instead of increasing biomass particularly at low watering levels. However, at each nutrient level, growth and storage increased with increasing moisture availability. As compared to Q. leucotrichophora, seedlings of P. roxburghii favoured growth over storage (according to its more competitive strategy), although this species accumulated more carbon and nitrogen towards the higher nutrient level.


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