Comparison of crown density assessments on trees within the stand and on ride edges within the forest

2002 ◽  
Vol 157 (1-3) ◽  
pp. 1-6 ◽  
Author(s):  
D. Durrant ◽  
R. Boswell
Keyword(s):  
Crown Density

scholarly journals Soil enzyme activity in the dry valley phytocenoses under the influence of Acer negundo L.

2021 ◽  
Vol 31 ◽  
pp. 00029
Author(s):  
Oksana Tsandekova
Keyword(s):  
Enzyme Activity ◽  
Hydrolytic Enzymes ◽  
Soil Condition ◽  
Invertase Activity ◽  
Horizontal Differentiation ◽  
Natural Ecosystems ◽  
Crown Density ◽  
Dry Valley ◽  
Medium Activity ◽  
And Control

The activity of hydrolytic enzymes in the soil of dry valley phytocenoses under the influence of ash-leaved maple was investigated. The research objects were selected taking into account the ranking of plantations by crown density. Soil samples were collected depending on the horizontal differentiation of communities in the undercrown and outer zones of phytogenic fields. An increase in the enzyme activity during the period of active tree growth among experimental and control samples was established. Among the enzymes, invertase demonstrated the highest activity, while protease and phosphatase were characterised by medium activity. An increased invertase activity was found in the trees with a high crown density as compared to the trees of other groups. The obtained data can be used as diagnostic indicators of soil condition for monitoring natural ecosystems.

scholarly journals Analysis of the vitality of the Agathis dammara tree at Situ Gunung Resort, Gunung Gede Pangrango National Park

2021 ◽  
Vol 912 (1) ◽  
pp. 012071
Author(s):  
I R Maulana ◽  
Rahmat Safe’i ◽  
Siti Fauzia Rochmah
Keyword(s):  
Health Status ◽  
National Park ◽  
Health Assessment ◽  
Forest Health ◽  
Crown Condition ◽  
Tree Damage ◽  
Damage Level ◽  
A Value ◽  
Crown Density ◽  
Lower Stem

Abstract Vitality is the vigor value of the trees in responding to environmental conditions. Determined vitality value was by calculating tree damage and crown condition. The Agathis dammara tree is a native Indonesian plant in the Situ Gunung Resort, Gunung Gede Pangrango National Park (TNGGP). This study aims to determine the vitality and value of the health status of Agathis dammara trees at Situ Gunung Resort, TNGGP. The research location is in the utilization zone at the Situ Gunung Resort, TNGGP, covering an area of 700 haBuilt observation plots based on the Forest Health Monitoring (FHM) cluster plot design as many as nine cluster plots. They have calculated tree damage based on the location where found the damage was in the FHM method. Calculated condition canopy based on five parameters visual crown. Assessment of tree health status uses a forest health assessment information system. The results showed that the location where found the most damage was at the root and lower stem (code 2) as many as 67 trees, dominated by liana damage (code 20) as many as 43 trees, with an average damage level of 35%. The live crown ratio 20-35%, crown density 25-50%, foliage transparency 50-70%, crown diameter 2.5-10 m, and dieback 0-5%. The value of the health status of the Agathis dammara tree has a value of 1.69-2.44. Thus, these conditions illustrate that the vitality and value of the health status of Agathis dammara trees at Situ Gunung Resort, TNGGP are in the medium criteria and category.

scholarly journals Breeding value of Norway spruce (Picea abies [L.] Karst.)

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 17-23
Author(s):  
Rożkowski KR
Keyword(s):  
Survival Rate ◽  
Norway Spruce ◽  
Growth Traits ◽  
Block Design ◽  
Basal Area ◽  
Tree Height ◽  
Breeding Value ◽  
Cross Sectional ◽  
Qualitative Traits ◽  
Crown Density

This is the first report on measurements and observations of an experimental plot of 35-year-old Norway spruce, established in 1970 by the Institute of Dendrology at K&oacute;rnik, where progenies of 22 plustrees from the Kłodzko Forest District were planted. The experiment was established in an incomplete block design of 20 families with 3 replications. Survival rate and growth traits determining productivity (plant height or basal area &ndash; stem cross-sectional area at breast height per 1&nbsp;ha) were assessed in several years, and qualitative traits (trunk straightness; degree of natural pruning; thickness, length and angle of branches; crown density; presence of galls caused by the aphids Adelges laricis Vall. and Sacchiphantes viridis Ratz.) were evaluated once in 2001. Analysis of variance revealed significant differences between the half-sib families in survival rate and productivity but no significant differences in qualitative traits. Statistically significant positive correlations were found between trunk straightness at the age of<br />&nbsp;36 years and height of 2-year-old seedlings in the nursery, and between the degree of natural pruning at the age of 36 years and both tree height at the age of 9 years and basal area at the age of 13 years.

Review of Vegetation Classification and Mapping Systems Undertaken by Major Forested Land Management Agencies in Australia

1997 ◽  
Vol 45 (6) ◽  
pp. 929 ◽  
Author(s):  
D. Sun ◽  
R. J. Hnatiuk ◽  
V. J. Neldner
Keyword(s):  
Land Management ◽  
Vegetation Classification ◽  
Classification Systems ◽  
Vegetation Coverage ◽  
Forest Land ◽  
Wood Production ◽  
Raw Data ◽  
Quantitative Measurements ◽  
Crown Density ◽  
Mapping Systems

This paper provides a detailed review of the major vegetation classification and mapping systems used by the management agencies with primary responsibilities for forested land in Australia. It focuses on the clarification of vegetation units and methodologies used. The paper also provides a comparison of the different nomenclatures against a simplified standard to show how the different systems relate to each other. In Australia, different systems for classifying and describing forest vegetation have been developed by various forest land management agencies to suit their own situations. Most vegetation classification systems reviewed are similar in using floristics and structure as the two primary elements in classifying vegetation types, and all use growth form (physiognomy) to distinguish vegetation units. The classification and mapping systems for wood production purposes differ from those for conservation and environment purposes in several aspects—wood production classifications emphasise commercial tree species and/or attributes such as height, whereas conservation classifications emphasise ecology, vegetation coverage, and the importance of understorey species. There are three broad strategic approaches in the vegetation classification programs being undertaken by the major forest land management agencies in Australia: (1) conducting a single classification across the whole of the agencies’ land in a State; (2) conducting a vegetation classification at the regional level, but using the same methods in each region; and (3) using different methods depending on the specific objectives of individual studies. This paper highlights the value of accurate quantitative measurements in the field. For example, for the two key structural attributes of height and crown density, the measured raw data can be accommodated by a number of different classification schemes whereas if the raw data consists of only records by predetermined classes, then such accommodation is difficult and loses precision.

scholarly journals Relationship between Species Richness, Biomass and Structure of Vegetation and Mycobiota along an Altitudinal Transect in the Polar Urals

2020 ◽  
Vol 6 (4) ◽  
pp. 353
Author(s):  
Anton G. Shiryaev ◽  
Ursula Peintner ◽  
Vladimir V. Elsakov ◽  
Svetlana Yu. Sokovnina ◽  
Denis A. Kosolapov ◽  
...  
Keyword(s):  
Species Richness ◽  
Vascular Plants ◽  
Fungal Species ◽  
River Valley ◽  
Tree Age ◽  
Ecological Groups ◽  
Polar Urals ◽  
Crown Density ◽  
Aphyllophoroid Fungi ◽  
The Polar Urals

Aboveground species richness patterns of vascular plants, aphyllophoroid macrofungi, bryophytes and lichens were compared along an altitudinal gradient (80–310 m a.s.l.) on the Slantsevaya mountain at the eastern macroslope of the Polar Urals (Russia). Five altitudinal levels were included in the study: (1) Northern boreal forest with larch-spruce in the Sob’ river valley habitats; (2–3) two levels of closed, northern boreal, larch-dominated forests on the slopes; (4) crook-stemmed forest; (5) tundra habitats above the timberline. Vascular plant or bryophyte species richness was not affected by altitudinal levels, but lichen species richness significantly increased from the river valley to the tundra. For aphyllophoroid macrofungi, species richness was highest at intermediate and low altitudes, and poorest in the tundra. These results indicate a positive ecotone effect on aphyllophoroid fungal species richness. The species richness of aphyllophoroid fungi as a whole was neither correlated to mortmass stocks, nor to species richness of vascular plants, but individual ecological or morphological groups depended on these parameters. Poroid fungal species richness was positively correlated to tree age, wood biomass and crown density, and therefore peaked in the middle of the slope and at the foot of the mountain. In contrast, clavarioid fungal species richness was negatively related to woody bio- and mortmass, and therefore peaked in the tundra. This altitudinal level was characterized by high biomass proportions of lichens and mosses, and by high litter mortmass. The proportion of corticoid fungi increased with altitude, reaching its maximum at the timberline. Results from the different methods used in this work were concordant, and showed significant patterns. Tundra communities differ significantly from the forest communities, as is also confirmed by nonmetric multidimensional scaling (NMDS) analyses based on the spectrum of morphological and ecological groups of aphyllophoroid fungi.

scholarly journals Patterns in woody vegetation structure across African savannas

2017 ◽  
Vol 14 (13) ◽  
pp. 3239-3252 ◽  
Author(s):  
Christoffer R. Axelsson ◽  
Niall P. Hanan
Keyword(s):  
Vegetation Structure ◽  
Woody Plants ◽  
Woody Plant ◽  
Annual Precipitation ◽  
Woody Vegetation ◽  
Mean Annual Precipitation ◽  
Crown Density ◽  
Woody Cover ◽  
Ecohydrological Processes ◽  
Crown Size

Abstract. Vegetation structure in water-limited systems is to a large degree controlled by ecohydrological processes, including mean annual precipitation (MAP) modulated by the characteristics of precipitation and geomorphology that collectively determine how rainfall is distributed vertically into soils or horizontally in the landscape. We anticipate that woody canopy cover, crown density, crown size, and the level of spatial aggregation among woody plants in the landscape will vary across environmental gradients. A high level of woody plant aggregation is most distinct in periodic vegetation patterns (PVPs), which emerge as a result of ecohydrological processes such as runoff generation and increased infiltration close to plants. Similar, albeit weaker, forces may influence the spatial distribution of woody plants elsewhere in savannas. Exploring these trends can extend our knowledge of how semi-arid vegetation structure is constrained by rainfall regime, soil type, topography, and disturbance processes such as fire. Using high-spatial-resolution imagery, a flexible classification framework, and a crown delineation method, we extracted woody vegetation properties from 876 sites spread over African savannas. At each site, we estimated woody cover, mean crown size, crown density, and the degree of aggregation among woody plants. This enabled us to elucidate the effects of rainfall regimes (MAP and seasonality), soil texture, slope, and fire frequency on woody vegetation properties. We found that previously documented increases in woody cover with rainfall is more consistently a result of increasing crown size than increasing density of woody plants. Along a gradient of mean annual precipitation from the driest (< 200 mm yr−1) to the wettest (1200–1400 mm yr−1) end, mean estimates of crown size, crown density, and woody cover increased by 233, 73, and 491 % respectively. We also found a unimodal relationship between mean crown size and sand content suggesting that maximal savanna tree sizes do not occur in either coarse sands or heavy clays. When examining the occurrence of PVPs, we found that the same factors that contribute to the formation of PVPs also correlate with higher levels of woody plant aggregation elsewhere in savannas and that rainfall seasonality plays a key role for the underlying processes.

scholarly journals Effect of elevation and latitude on spring phenology of Rhododendron at Kanchenjunga Conservation Area, East Nepal

2013 ◽  
Vol 1 (4) ◽  
pp. 253-257 ◽  
Author(s):  
Sailesh Ranjitkar
Keyword(s):  
Elevation Gradient ◽  
Onset Time ◽  
Conservation Area ◽  
Spring Phenology ◽  
Flowering Duration ◽  
Short Term Change ◽  
Term Change ◽  
Crown Density ◽  
Kanchenjunga Conservation Area ◽  
Determine Effect

Mountainous terrain in East corner of Nepal is good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried our following the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was determined. Elevation, latitude and longitude were regressed against flower onset to determine effect of each variable on flower onset. Delay in flower onset with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also indicates that the reproductive timing might plastic enough to cope with short-term change in environment. DOI: http://dx.doi.org/10.3126/ijasbt.v1i4.9154 Int J Appl Sci Biotechnol, Vol. 1(4): 253-257

Effects of continuous grazing and seasonal closures on the performance and persistence of some sown temperate perennial grasses, North-West Slopes New South Wales

2002 ◽  
Vol 42 (4) ◽  
pp. 431 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
Festuca Arundinacea ◽  
Perennial Grass ◽  
Basal Area ◽  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Individual Species ◽  
North West ◽  
Basal Cover ◽  
Crown Density ◽  
Plant Frequency

A split-plot experiment was sown at Tamworth in 1992 to examine the effects of continuous sheep grazing and seasonal closures (autumn, spring, spring + autumn, and summer + winter) on the herbage mass, plant frequency and basal cover of 5 perennial grasses, when sown as monocultures or with a perennial (Trifolium repens cv. Haifa) or annual legume (Trifolium subterraneum var. subterraneum cv. Seaton Park). Plant basal area and crown density data were also collected. The perennial grasses were Phalaris aquatica cv. Sirosa, Festuca arundinacea, cv.� Demeter, Lolium perenne cv. Kangaroo Valley, Austrodanthonia richardsonii (syn. Danthonia richardsonii) cv.�Taranna, and A. bipartita (syn. D. linkii) cv. Bunderra. There was no significant effect of legume presence on the herbage mass or persistence of the perennial grasses. The only treatment that had a significant effect (P< 0.05) on either herbage mass, plant frequency or basal cover data was the grazing treatment × perennial grass interaction in each of the years 1993-98, except for herbage mass in December 1993 and basal cover in October 1998. In all of the grazing treatments examined, Kangaroo Valley ryegrass failed to persist after spring 1994; Demeter fescue had failed by spring 1997 and Sirosa phalaris by spring 1998. Six years after sowing the only temperate grass cultivars that were persisting in all grazing treatments were the native perennials, Taranna and Bunderra. Hence, the data represent the entire stand life from sowing to eventual failure for the 3 introduced cultivars. While grazing treatment effects within years for individual species were significant, overall grazing had little effect on the rate of decline in herbage mass and persistence of Kangaroo Valley, Demeter and Sirosa. By 1998, grazing treatment had no significant effect on the herbage mass and basal cover of Taranna and Bunderra, but their plant frequencies were lowest in the spring rest and summer + winter rest treatments.

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