scholarly journals Ease of Access to An Alternative Food Source Enables Wallabies to Strip Bark in Tasmanian Pinus radiata Plantations

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 387 ◽  
Author(s):  
Anna H. Smith ◽  
David A. Ratkowsky ◽  
Timothy J. Wardlaw ◽  
Caroline L. Mohammed
Keyword(s):  
Pinus Radiata ◽  
Food Source ◽  
Floristic Composition ◽  
Radiata Pine ◽  
Early Summer ◽  
Bark Stripping ◽  
Site Factors ◽  
Generalist Herbivore ◽  
The Difference ◽  
Main Food Source

Bark stripping by the Bennett’s wallaby (Macropus rufogriseus (Desmarest) subsp. rufogriseus) from the lower stems of 3–6-year-old radiata pine (Pinus radiata D. Don) causes significant damage in Tasmanian plantations. The usual diet of this generalist herbivore is mainly grasses and broadleaved forbs. As the factors that attract a wallaby to supplement its diet by eating the bark of plantation pine trees are currently not elucidated, the present study aimed to determine how the incidence and severity of bark damage in 12 Tasmanian radiata pine plantations was influenced by various inter-site factors such as the floristic composition of the surrounding forest, and by various intra-site factors such as the height and circumference of individual trees, the number of branches in the first two whorls at the base of the tree, and their internode lengths. It was found that the greater the percentages of bare ground, bracken, and moss present in the five plots at each site, and the greater the percentage of grass, the wallaby’s main food source, the greater the likelihood of bark stripping. The difference between the mean minimum soil and air temperatures in spring, a driving force for carbohydrate production that occurs with tree growth in spring or early summer, was the only meteorological observation at the sites that was found to be significantly related to the extent of bark stripping.

scholarly journals Ease of Access to an Alternative Food Source Enables Wallabies to Strip Bark in Tasmanian Pinus Radiata Plantations

2020 ◽  
Author(s):  
Anna Smith ◽  
David Ratkowsky ◽  
Timothy Wardlaw ◽  
Caroline Mohammed
Keyword(s):  
Tree Growth ◽  
Pinus Radiata ◽  
Food Source ◽  
Floristic Composition ◽  
Radiata Pine ◽  
Early Summer ◽  
Bark Stripping ◽  
Site Factors ◽  
Generalist Herbivore ◽  
Ease Of Access

Bark stripping by the Bennett’s wallaby (Macropus rufogriseus rufogriseus) from the lower stems of 3–6-year-old radiata pine (Pinus radiata) causes significant damage in Tasmanian plantations. The usual diet of this generalist herbivore is mainly grasses and broadleaved forbs. As the factors that attract wallabies to supplement its diet by eating the bark of plantation pine trees are currently not elucidated, the present study aimed to determine how the incidence and severity of bark damage in 12 Tasmanian radiata pine plantations was influenced by various inter-site factors such as the floristic composition of the surrounding forest and by various intra-site factors such as the height and circumference of individual trees, the number of branches in the first two whorls at the base of the tree, and their internode lengths. Site differences in the observed percentage of bark stripping were found to be related to ‘ease of access’ variables such as bare ground, bracken, and moss, ‘hindrance to access’ variables such as rock and woody debris, and the percentage of grass, the wallaby’s main food source, present in the five plots at each site. The difference between the mean minimum soil and air temperatures in spring, a driving force for carbohydrate production that occurs with tree growth in spring or early summer, was the only meteorological observation at the sites that was found to be statistically significant. Nevertheless, there was no direct evidence that it was the movement of sugars in the phloem tissue accompanying tree growth which provided wallabies with a supplementary food source.

Photosynthetic Activity of Leaves of Pinus radiata and Nothofagus fusca After 1 Year of Growth at Elevated CO2

1996 ◽  
Vol 23 (5) ◽  
pp. 623 ◽  
Author(s):  
KP Hogan ◽  
D Whitehead ◽  
J Kallarackal ◽  
JG Buwalda ◽  
J Meekings ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Pinus Radiata ◽  
Photosynthetic Activity ◽  
Photosynthetic Capacity ◽  
Radiata Pine ◽  
Rubisco Activity ◽  
Co2 Partial Pressure ◽  
Partial Pressures ◽  
The Difference ◽  
Triose Phosphate Utilisation

Radiata pine (Pinus radiata D.Don) and red beech (Nothofagus fusca (Hook. f.) Oerst.) were grown for over 1 year at elevated (ELEV, 64 Pa) and ambient (AMB, 38 Pa) CO2 partial pressure in open-top chambers. Springtime measurements of overwintering leaves showed that light- and CO2-saturated photosynthetic rates (Amax) of pine leaves were similar for the two treatments (AMB: 6.7 � 1.08 μmol m-2 s-1, mean � 1 s.e.; ELEV: 6.6 � 0.47) but, for beech leaves, Amax was greater for AMB plants (8.8 � 0.90 μmol m-2 s-1) than for ELEV plants (6.10 � 0.71). Summertime measurements of leaves grown that spring showed that for pine, Amax was similar in the two CO2 treatments (AMB 14.9 μmol m-2 s-1 � 0.80; ELEV: 13.5 � 1.9) while, for beech, Amax was higher in AMB plants (21.0 � 1.1) than in ELEV plants (17.2 � 1.9), although the difference was not statistically significant. These results indicate downregulation of photosynthetic capacity of beech but not pine. Vcmax did not differ between treatments within species, suggesting that there was no acclimation of rubisco activity. Triose phosphate utilisation limitation may have contributed to the downregulation of Amax in beech. For pine, photosynthesis at treatment CO2 partial pressures was greater in ELEV plants in both spring and summer. For beech measured at treatment CO2 partial pressures, photosynthesis was greater in ELEV plants in summer, but was similar between treatments in the springtime.

scholarly journals Effects of Environmental Temperature onCapnodis tenebrionisAdult Phenology

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Carmelo Peter Bonsignore
Keyword(s):  
Late Summer ◽  
Early Summer ◽  
Adult Density ◽  
Degree Days ◽  
Continuous Increase ◽  
Climate Conditions ◽  
Average Annual Temperature ◽  
Activity Temperature ◽  
The Difference ◽  
New Generation

The phenology ofCapnodis tenebrionisadults was presented with reference to two different climate conditions. In a temperate moderate-warm climate, adult density showed two separate peaks during the year: one in early summer of the overwintering generation and one with beetles emerging in the late summer. In a warmer semiarid climate, the overwintering adults and the new generation overlapped during summer with a continuous increase of adult density. The difference in the average annual temperature between areas during the study period was almost3∘C, and, in the warmer area, the new generation ofC. tenebrionisemerged at least one month earlier. To make a prediction of adult presence, a model utilizing degree-days was developed from data collected over a five-year period. Models obtained from equations (Logistic 4-parameter,y(x)=yo+a/(1+(x/xo)b)) of each year were developed to describe the relationship between degree-day accumulation (with a minimal threshold activity temperature of14.21∘Ccalculated in the laboratory) and the cumulative percentage of adult presence. According to the overall model, the 50% of overwintering beetles occurred at 726 degree-days (Biofix: 1st March) and the emerging beetles occurred at 801 degree-days (Biofix: 1st July). The results show that a change in temperature is an important aspect that highlights the adaptability of this species.

scholarly journals Enhancement of the physical and mechanical properties of wood using a novel organo-montmorillonite/hyperbranched polyacrylate emulsion

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jianfeng Xu ◽  
Xiaoyan Li ◽  
Ling Long ◽  
Ru Liu
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Pinus Radiata ◽  
Wood Sample ◽  
Wood Cell Wall ◽  
Physical And Mechanical Properties ◽  
Radiata Pine ◽  
Compact Structure ◽  
Populus Cathayana ◽  
Modified Wood

AbstractIn this work, a novel waterborne hyperbranched polyacrylate (HBPA) dispersed organo-montmorillonite (OMMT) emulsion was synthesized and used for the treatment of wood in a vacuum environment in order to enhance the physical and mechanical properties of the wood. The sapwood of Cathay poplar (Populus cathayana Rehd.) and Radiata pine (Pinus radiata D.Don) were used as the samples for experimentation. The results showed that the physical and mechanical properties of the wood improved significantly due to the successful penetration of the OMMT and HBPA into the wood cell wall. From it was also observed that OMET completely exfoliated from the HBPA matrix and formed a hydrophobic film covering on the inside walls of the cell lumen. Further, it was observed that the poplar sample displayed better mechanical properties than the pine sample because the pine has a more compact structure when compared to poplar and contains rosin. Furthermore, it was also observed that the mechanical properties of the modified wood sample gradually improved with an increase in the concentration of the emulsion. However, excessive concentration (>4 wt%) did not lead to further improvement.

scholarly journals Seasonal patterns of pasture production in the Bay of Plenty and Waikato

1991 ◽  
pp. 67-72
Author(s):  
J.A. Baars ◽  
G.J. Goold ◽  
M.F. Hawke ◽  
P.J. Kilgarriff ◽  
M.D. Rolm
Keyword(s):  
Growth Rates ◽  
Early Spring ◽  
Early Summer ◽  
Growth Patterns ◽  
Climatic Data ◽  
Large Contribution ◽  
Pasture Production ◽  
Summer Peak ◽  
The Difference

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

scholarly journals POLA SEBARAN IKAN PADA MUSIM BARAT DAN PERALIHAN DI PERAIRAN UTARA JAWA TENGAH

2017 ◽  
Vol 14 (1) ◽  
pp. 67
Author(s):  
Asep Priatna ◽  
Mohammad Natsir
Keyword(s):  
Food Source ◽  
Target Strength ◽  
Fish Density ◽  
Current Direction ◽  
North West ◽  
Pelagic Fishes ◽  
Central Java ◽  
The Difference ◽  
West Monsoon ◽  
Demersal Fishes

Penelitian ini bertujuan untuk mempelajari perbedaan pola sebaran ikan pada musim barat dan peralihan di perairan utara Semarang sampai dengan Brebes, berdasarkan pada pengambilan contoh akustik dan oseanografi pada bulan Desember 2005 dan Mei 2006. Hasil menunjukkan secara spasial, pada musim barat di perairan utara Semarang sampai dengan Brebes kepadatan ikan pelagis lebih besar di daerah yang lebih dangkal yaitu sebelah selatan pada kedalaman <40 m, semakin ke tengah kepadatan semakin berkurang. Dilihat dari nilai target strength yang terdeteksi yaitu antara -60 sampai dengan -50 dB bahkan didominasi oleh ikan -60 sampai dengan -55 dB, sasaran merupakan ikan pelagis kecil yang rata-rata mempunyai ukuran 4 sampai dengan 12,5 cm. Pada musim peralihan sebaran kepadatan ikan pelagis kecil cenderung lebih merata dengan jumlah yang lebih rendah daripada jumlah ikan pada musim barat. Faktor pergerakan arah arus dan keberadaan sumber makanan yang lebih besar pada musim barat diduga merupakan penyebab perbedaan tersebut. Ikan pelagis kecil pada musim peralihan berukuran lebih besar dibandingkan ketika musim barat, dengan nilai target strength yang terdeteksi antara -60 sampai dengan -45 dB atau sekitar 4 sampai dengan 22 cm dan didominasi oleh ikan yang berukuran -55 sampai dengan -50 dB atau sekitar 7 sampai dengan 12,5 cm. Sebaran kepadatan Ikan demersal hampir merata pada ke-2 musim tersebut, pada musim peralihan kepadatan lebih rendah daripada musim barat. Ikan demersal pada musim barat terdiri atas ikan berukuran kecil (-55 sampai dengan -50 dB) atau sekitar 7 sampai dengan 12,5 cm terutama di daerah pada kedalaman <40 m, semakin ke tengah ukuran semakin besar yaitu antara -50 sampai dengan -45 dB atau sekitar 12,5 sampai dengan 22 cm. Pada musim peralihan, ikan demersal dengan target strength -55 sampai dengan -50 dB terdapat di kedalaman <40 m. Ikan demersal dengan ukuran -50 sampai dengan -45 dB mendominasi periode ini. Pada kedalaman >45 m terdeteksi ikan -45 sampai dengan -35 dB yang berkisar 22 sampai dengan 70 cm. The aim of this study is to understood the difference of fish pattern distributions at North West and intermonsoon in North of Central Java waters, based on acoustic and oceanography sampling in December 2005 and May 2006. At North West monsoon, the density of pelagic fishes was more gathering in narrower areas <40 m, and low fish density was going to middle areas. Seen from target strength the value was detected about -60 to -50 dB and it was dominated by fishes -60 to -55 dB, the targets for small pelagic fishes are about 4 to 12,5 cm. At the intermonsoon, distribution of small pelagic fishes density tends to be flat, but fish density at this time was the lower than North West monsoon. The higly current direction and food source factor at North West monsoon may cause this difference. The size of small pelagic fishes at the intermonsoon was bigger than fishes at North West monsoon, which target strength value was detected about -60 to -45 dB or 4 to 22 cm and dominated by fishes -55 to -50 dB of about 7 to 12,5 cm. The density distribution of demersal fishes almost flat at both monsoon. How ever at intermonsoon, the demersal fishes density was lower than that at North and West season. Demersal fishes at North West monsoon consisted of small fishes (-55 to -50 dB) with size of about 7 to 12,5 cm especially in narrow areas <40 m, and fish sizes the larger (-50 to -45 dB or 12,5 to 22 cm) were going to the middle areas. At intermonsoon, there were demersal fishes with target strength -55 to -50 dB at <40 m. Demersal fishes with target strength -55 to -50 dB were dominant at this time. At areas >45 m it was detected fishes of -45 to -35 dB target strength of about 22 to 70 cm.

Performance differences in Pinus radiata progeny with differing site nutrient availability

2004 ◽  
Vol 34 (12) ◽  
pp. 2410-2423 ◽  
Author(s):  
S D Carson ◽  
M F Skinner ◽  
A T Lowe ◽  
M O Kimberley
Keyword(s):  
Nutrient Availability ◽  
Pinus Radiata ◽  
Nutrient Concentration ◽  
Radiata Pine ◽  
Substantial Improvement ◽  
Treatment Combination ◽  
Control Seed ◽  
Foliar Nutrient ◽  
Selection For ◽  
Selection Of

Two intensive harvesting trials with contrasting nutrient capital were examined for genetic × environment interactions to age 5 years after planting. Treatments included differences in removal of organic matter and in site preparation and weed control, with each treatment having both fertilized and nonfertilized plots. Three harvest treatments (both fertilized and nonfertilized) were common to both sites, with two additional treatments at one site. There were four replicate plots of each treatment combination at each site, with two trees from each of three control seed lots and 47 open-pollinated families chosen to represent the range of performance for growth planted in each plot. Large differences among sites and among treatments in both growth and foliar nutrient concentration were observed. Genetic × site interactions and genetic × treatment within site interactions were seldom significant. Significant interactions did not appear to be related to changes in rankings of families, but rather to the differences in variance among families in different treatments. This study suggests that selection of specific radiata pine (Pinus radiata D. Don) families for better growth performance on nutrient-deficient sites in New Zealand would not result in substantial improvement over selection for growth on all sites disregarding nutrient availability.

scholarly journals Structure, Mechanical Performance, and Dimensional Stability of Radiata Pine (Pinus radiata D. Don) Scrimbers

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Jinguang Wei ◽  
Fei Rao ◽  
Yuxiang Huang ◽  
Yahui Zhang ◽  
Yue Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pinus Radiata ◽  
Dimensional Stability ◽  
High Performance ◽  
Water Resistance ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Radiata Pine ◽  
Specific Strength ◽  
Shearing Strength

Natural wood has certain advantages such as good processability and high specific strength and thus has been used for millennium as a structural material. But the mechanical performance and water resistance, particularly for fast-growing species, are unsatisfactory for high-end applications. In this study, the “new-type” scrimber technology was introduced to radiata pine (Pinus radiata D. Don) scrimbers. The structure, mechanical properties, and dimensional stability of the scrimber panels were investigated. Results showed that OWFMs as basic units of scrimber had been very even in size and superior permeability. The scrimbers exhibited a three-dimensional porous structure, and the porosity had a decrease with increasing density. Both OWFMs and densification contributed to the high performance in terms of mechanical properties and water resistance. The flexural, compressive, and short-beam shearing strength were significantly enhanced with increasing density. As the density was 0.80 g cm−3, the flexural strength (MOR) was approximately 120 MPa, much larger than many selected wood-based panels. Moreover, the water resistance and dimensional stability also were closely related to the density. At the density of 1.39 g cm−3, the water absorption rate and thinness swelling rate of the panels in boiled water were only 19% and 5.7%, respectively.

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