The benefits of seed enrichment on sandalwood (Santalum spicatum) populations, after 17 years, in semi-arid Western Australia

2014 ◽  
Vol 36 (5) ◽  
pp. 475 ◽  
Author(s):  
Jonathan E. Brand ◽  
Benjamin Sawyer ◽  
David R. Evans
Keyword(s):  
Western Australia ◽  
Seedling Survival ◽  
Size Class ◽  
Stem Diameter ◽  
Class Structure ◽  
Large Trees ◽  
Land Systems ◽  
Santalum Spicatum ◽  
Semi Arid ◽  
Germinated Seeds

Initially, the size-class structure of 1067 natural sandalwood (Santalum spicatum) trees and seedlings, growing in populations at three semi-arid sites (Burnerbinmah, Ninghan and Goongarrie) in Western Australia, was measured during 1996–97. These same populations, and any new sandalwood seedlings and small trees that had established after 1996–97, were measured again after 17 years (2013). Size-class structure was assessed by measuring over-bark stem diameter at 150 mm above the ground. Populations of sandalwood trees at the Burnerbinmah and Ninghan sites failed to regenerate and, after 17 years, they contained only 0–3% small trees and 0–2% seedlings. Their overall population size declined by 21–24% and, combined with recruitment failure, these natural stands of sandalwood may largely disappear within 50–60 years. At the Goongarrie site, the proportion of large trees within the natural population increased from 58% to 82%. The proportion of small trees was constant at 13–16%, while seedlings declined from 29% to 2%. The population reduced by 35%, mainly due to high seedling mortality. Although the population was in decline, there appeared to be enough small trees and seedlings to maintain the population longer than at both the Burnerbinmah and Ninghan sites. In a second study, 16 640 sandalwood seeds were sown at the same three sites during 1996–97, and then assessed for germination, survival, growth and fruit production over 17 years. Sandalwood germination and growth were compared between locations, fencing treatments and land systems. Seed enrichment was successful at each site with 27–45% germination and 6–20% survival (from germinated seeds) after 17 years. The overall seedling survival rates (from total seeds sown) ranged from 2.1% to 5.2%. Mean stem diameter of seedlings was significantly larger at Goongarrie (37 mm) than at both Burnerbinmah and Ninghan (20–22 mm) sites. Grazing significantly affected the performance of sandalwood seedlings at an age of 17 years at the Ninghan site. At this site, seedling survival (from germinated seeds) was 16% in the fenced plots compared with only 6% in the unfenced plots. Mean stem diameter in the fenced plots (24 mm) was also significantly greater than in the unfenced plots (11 mm). Land systems did not affect survival of sandalwood seedlings at the Burnerbinmah site but had a significant impact at the Goongarrie site after 17 years. Seedling survival was significantly greater on the hills and ridges than those growing on the plains with granite and red sand plains. Seed-enrichment programs are recommended to improve long-term regeneration and sustainability of sandalwood trees.

scholarly journals Size-class structure of the forests of Finland during 1921–2013: a recovery from centuries of exploitation, guided by forest policies

2019 ◽  
Vol 139 (2) ◽  
pp. 279-293
Author(s):  
Helena M. Henttonen ◽  
Pekka Nöjd ◽  
Susanne Suvanto ◽  
Juha Heikkinen ◽  
Harri Mäkinen
Keyword(s):  
Land Use ◽  
Geographical Area ◽  
Species Group ◽  
Size Class ◽  
Class Structure ◽  
Initial State ◽  
Frequency Distributions ◽  
Size Classes ◽  
Growing Stock ◽  
Large Trees

AbstractFrequency distributions of tree diameters are a powerful tool for analyzing changes of tree populations in large areas. We analyzed the densities and mean volume estimates of trees in different size classes for the Finnish forests over the time-span of the National Forest Inventories (1921–2013). The results display a general increase in trees in all size classes, species group and geographical area, mainly after the 1970s. The densities of medium- and large-sized conifers showed large increases in the southern boreal subzone, spruces even more than pines. Small- to medium-sized pines have increased in the middle and northern boreal subzones. The shifts in growing stock are related to changing land use, resulting from the development of the society. The low quantities of both growing stock and large trees during the 1920s reflect a poor initial state of forests. Several land use forms of the former agriculture-based society were detrimental to forests, including slash and burn agriculture, cattle grazing and tar production. The pressure from alternative land use forms was stronger in southern Finland, where the population density (people per km2) is much higher. Between 1971 and 2013, the changes in size-class structure can be attributed mainly to intensified silviculture boosted by actions of the Finnish governments, including both legislation and financial support for management activities. Not only the development of growing stock has exceeded expectations, but the increase has also concentrated in the economically valuable trees in the large size classes.

scholarly journals Demographic vulnerability of an extreme xerophyte in arid Australia

2018 ◽  
Vol 66 (1) ◽  
pp. 26 ◽  
Author(s):  
Lynda D. Prior ◽  
Quan Hua ◽  
David M. J. S. Bowman
Keyword(s):  
Radiocarbon Dating ◽  
Arid Zone ◽  
Size Class ◽  
Mean Annual Precipitation ◽  
Class Structure ◽  
Mature Trees ◽  
Basal Diameter ◽  
Large Trees ◽  
Callitris Glaucophylla

Callitris glaucophylla (syn. C. columellaris F.Muell.) is an iconic Australian conifer that is suffering a recruitment deficit over much of the arid zone. Here, seedling establishment requires a series of unusually wet years, and protection from high levels of herbivory. The aim of our study was to determine the size class structure of C. glaucophylla populations in the most arid part (150 mm mean annual precipitation) of its range, and particularly whether seedlings had established during a wet period in 2010/11. We sampled C. glaucophylla populations throughout the region, including inside a 6000 ha feral animal exclosure. We found no seedlings from 2010/11, except on drainage lines adjacent to roads. Of 255 plots centred on mature trees, only 2% contained older seedlings, and 8% contained saplings, with no differences inside or outside exclosure, and 84% of trees were larger than 20 cm basal diameter. Matching dates of known regeneration with long-term rainfall records suggested that successful regeneration of C. glaucophylla requires a total of 600–720 mm of rain over a 2 year period. Our radiocarbon dating showed the age of three large trees ranged from 106 to 268 years, signifying that such trees in this region likely have only 2–8 climatic opportunities to reproduce.

The influence of landforms on sandalwood (Santalum spicatum (R.Br) A.Dc.) size structure and density in the north-eastern goldfields, Western Australia

2002 ◽  
Vol 24 (2) ◽  
pp. 219 ◽  
Author(s):  
J. E. Brand ◽  
P. J. Jones
Keyword(s):  
Western Australia ◽  
Land Surface ◽  
Size Structure ◽  
The Other ◽  
Total Density ◽  
Surface Type ◽  
The North ◽  
North Eastern ◽  
Land Systems ◽  
Santalum Spicatum

The density of Santalum spicatum was compared between 'land systems' and between 'land surface types' on four sheep stations in the north-eastern Goldfields: Yakabindie, Tarmoola, Glenorn and Minara. S.A spicatum density was recorded in 4–6A ha transect plots, with a total of 14,090 ha surveyed. Within each transect plot, the S. spicatum were divided into five groups based on stem diameter at 150A mm: < 25 mm, 25–74 mm, 75–124 mm, 125–174 mm and > 174 mm. The proportion of S. spicatum in each of the five size categories was similar between land surface types and between land systems, with the majority in two groups: 75–124 mm and 125–174 mm. S. spicatum recruitment was low, with less than 1.5 % seedlings (< 25 mm) and 7.9 % saplings (25–74 mm). Total density of S. spicatum on hills and ridges (0.65 stems/ha) was significantly higher than any other land surface type. The sandplains (0.05 stems/ha) supported the least. Within land systems, Laverton and Bevon (both hills and ridges) had the highest S. spicatum density. Yakabindie supported higher densities of S. spicatum than the other stations.

Sandalwood (Santalum spicatum) establishment in the semi-arid and arid regions of Western Australia

2013 ◽  
Vol 35 (1) ◽  
pp. 109 ◽  
Author(s):  
Benjamin Sawyer
Keyword(s):  
State Government ◽  
Western Australia ◽  
Significant Relationship ◽  
Arid Regions ◽  
Annual Rainfall ◽  
European Settlement ◽  
Soil Preparation ◽  
Santalum Spicatum ◽  
Semi Arid Region ◽  
Semi Arid

Harvesting of sandalwood (Santalum spicatum) occurs mainly from wild stands in the semi-arid and arid regions (typical annual rainfall 150–300 mm) of Western Australia. Regeneration of wild sandalwood in these regions is believed to be low since the occurrence of changes in land use associated with European settlement. This is thought to be due to factors including drought, poor seed dispersal and grazing. The objective of the study was to increase the germination and establishment of sandalwood through exploring seed response to rainfall. Additionally, the potential of soil-preparation techniques to utilise trace amounts of moisture was investigated. Two 25-ha plots were located either side of the semi-arid–arid divide. Into the plots 16 replicates of the control and 96 replicates of treatments were installed and sown with 11 200 seeds. Rainfall and other weather parameters were recorded at each site with an automated weather station. The study was replicated in 2008 and 2009. It was concluded from the study that there was a statistically significant relationship between germination and rainfall. It is proposed that the germination threshold is 264 mm per year which coincides with the long-term annual rainfall average of Kalgoorlie, Western Australia. Furthermore, a statistically significant relationship between germination and soil preparation was demonstrated. Ripping crust-forming soils before sowing and the construction of water-harvest banks had a positive effect. Information gained from these studies has led to the Western Australian State Government implementing a seeding program to increase sandalwood regeneration in the semi-arid region.

Ecology of Sandalwood (Santalum Spicatum) Near Paynes Find and Menzies, Western Australia: Size Structure and Dry-Sided Stems.

1999 ◽  
Vol 21 (2) ◽  
pp. 220 ◽  
Author(s):  
JE Brand
Keyword(s):  
Western Australia ◽  
Size Structure ◽  
Grazing Intensity ◽  
Directional Pattern ◽  
Mature Trees ◽  
North West ◽  
Successful Recruitment ◽  
Land Systems ◽  
Pastoral Lease ◽  
Santalum Spicatum

Population size structure of sandalwood (Santalum spicatum) was studied on four pastoral leases near Paynes Find and Menzies, in semi-arid Western Australia. Stem diameter, height, height to crown and the orientation of dry-sided stems were recorded for 1017 individual sandalwood. Populations of S. spicatum at Paynes Find contained only mature trees, indicating no successful recruitment for at least 30 years. In contrast, populations of S, spicatum at Menzies had a high proportion of seedlings and saplings. Crown measurements of mature S. spicatum trees indicated high grazing intensity at Paynes Find: mean height to crown at Paynes Find (147-148 cm) was significantly higher than Menzies (92-94 cm). Dry-side percentage differed significantly between directional faces, consistent with sun damage. Highest mean dry-side percentages were on stem sides facing the sun between midday and late afternoon: west, north-west, south-west and north. This directional pattern was the same between pastoral leases, and there was no interaction between pastoral lease and dry-side direction. Mean percentage of mature trees with a dry-sided stem was also significantly higher at Paynes Find (76-82%) than at Menzies (42-46%). Significantly less foliage low to the ground on mature trees at Paynes Find may have exposed the stems to more sun damage. Land systems did not significantly influence dry-side direction on Burnerbinmah or Goongarrie. No S. spicatum seedlings or saplings had a dry-sided stem. Key words: Santalum spicatum, size structure, dry-sided stems

Screening of F1 progeny for selection of superior hybrids in mulberry (Morus spp.) - A simple approach PART I: Screening of seedlings in relation to seed size

2017 ◽  
Vol 6 (2) ◽  
pp. 5256
Author(s):  
Daryoush Shafiei ◽  
Prof. Basavaiah*
Keyword(s):  
Seed Size ◽  
Seedling Survival ◽  
Size Class ◽  
Medium Size ◽  
Screening Process ◽  
Size Classes ◽  
Morus Spp ◽  
In The Beginning ◽  
Selection Of ◽  
Size Grading

In mulberry (Morus spp.), the process of selection of promising hybrids from F1 population requires the screening of a large number of progenies and a long period. To develop a simple and faster approach for screening, studies were conducted using F1 seeds of two crosses. The details of screening studies conducted in relation to seed-size and seedling-size are reported separately in two parts. In this part, the F1 seeds were size-graded as small, medium and large seeds; their progenies were raised separately and screened in nursery. There was a considerable degree of variation in size of seeds and medium-size class seeds were in high percentage in both the crosses. The length, width and weight of seeds were also varied between the seed size classes significantly in both the crosses. The seed size classes differ with high significance in shoot length and Root collar diameter and also differ significantly in root length and weight of seedlings. The positive correlation between the seed size and growth of seedlings, seed size and germination, seed size and seedling survival in nursery indicated that size-grading of seeds and rejection of small seeds in the beginning of screening process may help to increase the efficiency of screening by increasing the chances of getting superior hybrids from limited progenies. However, confirmation on the performance of large seedlings from small seed size class may help to draw conclusion. Hence, the studies are continued with size- grading of seedlings in the next part of screening study.

Effects of Soil Moisture on Shrub Seedling Survival in Semi-Arid Grassland

Ecology ◽  
1991 ◽  
Vol 72 (3) ◽  
pp. 1138-1149 ◽  
Author(s):  
Graham N. Harrington
Keyword(s):  
Soil Moisture ◽  
Seedling Survival ◽  
Semi Arid

scholarly journals Growth and production of irrigated vitória pineapple grown in semi-arid conditions

2014 ◽  
Vol 36 (3) ◽  
pp. 693-703 ◽  
Author(s):  
Rodinei Facco Pegoraro ◽  
Bruna Aparecida Madureira de Souza ◽  
Victor Martins Maia ◽  
Uirá do Amaral ◽  
Marlon Cristian Toledo Pereira
Keyword(s):  
Plant Height ◽  
Biomass Production ◽  
Plant Traits ◽  
Block Design ◽  
Leaf Length ◽  
Stem Diameter ◽  
Plant Residue ◽  
Arid Conditions ◽  
Vegetative Biomass ◽  
Semi Arid

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

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