Seedlings In Plantations Research Articles

Comparison of carbon content between plantation and natural regeneration seedlings in Durango, Mexico.

Forest plantations and natural forests perform a relevant role in capturing CO2 and reducing greenhouse gas concentrations. The objective of this study was to compare the diameter increment, biomass and carbon accumulation in a plantation of Pinus durangensis and a naturally regenerated stand. The data were collected from 32 circular plots of 100 m2 (16 plots in the planted site and 16 in naturally regenerated area). At each plot, the diameter at the base (cm) and height (m) of all seedlings were measured using a Vernier and tape measure, and a seedling was destructively sampled collecting one cross-section at the base of the stump. The annual ring-width increment of each sampled seedling was recorded to obtain its diameter at the base and estimate annual aboveground biomass and carbon accumulation through allometric equations. The response variables were evaluated using mixed-effects ANOVA models. Results indicated that there were significant differences (P ≤ 0.05) on annual tree-ring width growth, biomass and carbon accumulation. The plantation seedlings showed significantly higher growth rates, biomass and carbon accumulation at most evaluated years. After 7 years of growth the lines of current annual increment (CAI) and mean annual increment (MAI) in basal diameter for both the plantation and the natural regeneration have not yet intersected. Both forest plantations and naturally regenerated stands of the studied tree species may be suitable alternatives to promote CO2 capture and increase timber production.

The phenotypic and genetic effects of drought-induced stress on apical growth, ring width, wood density and biomass in white spruce seedlings

Forest plantations play an important role in maintaining a supply of high-quality timber from managed forest. With an expected increase in the prevalence of drought in some forested areas, climate change increases concerns about future seedling growth. A promising approach to promote the suitability of plantation seedlings to current and future climate would be to use variation in growth and wood traits of trees under drought as selection criteria in tree breeding programs, especially at a young stage when they are most vulnerable to drought. We evaluated the genetic control of the growth and wood density response of white spruce clonal seedlings submitted to various drought conditions in a greenhouse experiment. By varying the watering treatment of 600 two year-old seedlings from 25 clones, we simulated three levels of drought-induced stress during two growing seasons. Apical and radial growth decreased markedly as the intensity of drought increased, whereas wood density tended to increase. We also developed a woody biomass index composed of wood density and ring area, which was observed to decrease slightly with increasing drought. There was important variation in all traits among clones and heritability tended to decrease with the intensity and duration of drought-induced stress, mainly for wood density and radial growth. However, the heritability of apical growth tended to increase under drought conditions. Our results show that the response of young white spruce clones to drought is highly variable, and together with the significant levels of heritability noted, the results indicate that multi-trait genetic selection for drought stress response at a young age could represent a promising approach to increase resilience to drought.

Examination of Compatibility of Autochthonous Pear Cultivars from the Region of Northeastern Bosnia with Vegetative Rootstock of the Genus Cydonia sp

Rootstocks of the genus Pyrus are easily adapted to climatic conditions and such trees are more resistant to Erwinia amylovora, but they also have disadvantages because these trees are more lush and difficult to grow in dense composition. The production of pears in a dense composition is a tendency of intensive pear production, and quince rootstocks are used for this purpose, because it is easier to control the height of the stem.
 The increase in the density of the composition in pear orchards is directly related to the use of vegetative rootstocks of less lushness, such as rootstocks of the genus Cydonia sp.The research included five autochthonous pear varieties: Takiša, Jeribasma, Šećerka, Karamut i Huseinbegovača.
 The tests were performed at the location Voćni rasadnik, Špionica, City Srebrenik, Tuzla Canton, Bosnia and Herzegovina, during the vegetation of 2021.
 Morphometric analyzes were performed on a sample of 30 seedlings for each pear variety. Average results are presented using MS Excel software packages.
 Seedlings of grafted varieties on the basis of diameter did not meet the conditions of marketing, while on the basis of vegetative growth, three varieties met the conditions of marketing of planting material. The research was conducted within the project number 02 / 9-712-1-5-4 / 21.
 Grafted autochthonous varieties in the year of grafting showed extremely good adhesion with the vegetative rootstock BA-29, but did not have a good diameter. Due to the possibility of remanence, it is necessary to continue research after planting seedlings in plantations.

Identifikasi Jenis dan Tingkat Serangan Hama Pada Pembibitan Tanaman Kelapa Sawit (Elaeis guineensi Jacq) di PT. Sentosa Kalimantan Jaya, Kabupaten Berau Provinsi Kalimantan Timur

Identification of Types and Levels of Pests Attack on Palm Plantation Seedlings (Elaeis guineensis Jacq) at PT. Sentosa Kalimantan Jaya, Berau District East Kalimantan Province. Under the guidance of Iin Arsensi and Purwati. This study aims to determine the types of pests that attack oil palm seedlings, the frequency and intensity of oil palm pest attack on the Main Nursery stage nursery. The research was arranged in Survey method, determining 5 research plots in one block diagonally by marking on each plot with plastic marker of seeds, so obtained 15 research plots contained in 3 block that is block J, I and D. Each research plot consists of 30 Oil palm seedlings so that the number of observed 450 seeds of oil palm. The results showed that the types of pests that attack the oil palm seedlings in Main Nursery are Tungau (Tetranychus piercei), Adoretus compressus Beetle, and Locusta migratoria manilensis (Locusta migratoria manilensis); Block Frequency A pest attack in the category of minor attacks is 51.33%, 24% attack, while the intensity of pest attacks is a mild attack category; Frequency of Block I attack of pests in light attack category is 49,33%, moderate attack 37,33%, heavy attack 2%, while intensity of pest attack moderate attack category; Frequency of Block D attack of pest in light attack category is 41,3%, moderate attack 41,3%, severe attack 7,3%, while intensity of pest attack moderate attack category;

Growth dynamics of endemic Dracaena cinnabari Balf. f. of Socotra Island suggest essential elements for a conservation strategy

Dragon’s blood tree, a flagship endemic species of Socotra, is threatened with extinction due to lack of natural regeneration, likely because of goat herbivory and/or climatic factors. Loss of dragon’s blood tree would result in loss of other native flora, heightening the importance of formulating a conservation strategy for it. Although artificial afforestation might be used to offset the lack of natural regeneration, it would have to overcome the same threats faced by naturally occurring seedlings. Moreover, there is no published information on the growth dynamics of seedlings in plantations in situ on Socotra. To fill this information gap, we compared seedling growth (total plant height, leaves number, stem height, stem diameter) over an 8-year period after planting at three sites that differed in the degree to which goats were excluded and in whether they were watered regularly over the period. In addition to developing a new classification of the growth stages, which will enable better tracking of population dynamics, we found that continuous goat exclusion was necessary to prevent seedling mortality. Also, although seedling growth overall was slow, growth parameters of regularly irrigated seedlings ranged from 156% to 446% of those not regularly watered, suggesting that this treatment can speed seedlings’ escape from goat browsing. For the dragon’s blood tree and likely for other taxa within this group, extremely slow growth and long generation times suggest that conservation and restoration efforts will require a commitment to active management that will last decades, rather than a short-term approach.

Sex‐biased parasitism of adult spring beetles, Heteronyx dimidiata and Heteronyx crinitus, by Tachinidae in Eucalyptus nitens plantations in Australia

AbstractParasitism of adult Heteronyx dimidiata (Erichson) and H. crinitus Blackburn (Scarabaeidae: Melolonthinae), that attack Eucalyptus nitens plantation seedlings in southern Australia, was recorded over 3 years. An undescribed genus of Blondeliini (Tachinidae: Exoristinae) was reared from both scarab species while a Palpostoma sp. (Tachiinae) was reared from H. crinitus. Flies were observed parasitising flying beetles by intercepting them mid‐air. Eggs were laid externally on the exoskeleton, mainly on the dorsum of abdominal tergites. Male H. dimidiata were parasitised significantly more (40%) than female conspecifics (13%) and male or female H. crinitus (both 13%), which was attributed to their greater flight activity searching for mates. Superparasitism was common in both species, particularly in male H. dimidiata (56% of parasitised beetles, up to 22 eggs/beetle), despite evidence that only a single tachinid could complete development in a beetle. Early stages of parasitism in H. dimidiata females did not appear to affect ovarian development nor the ability of beetles to feed on young trees. However, we infer that the tachinids had a significant impact on Heteronyx spp. populations through a reduction in adult beetle longevity and fitness.

Repellent and stocking guards reduce mammal browsing in eucalypt plantations

Mammalian herbivores regularly browse plantation seedlings. In many areas, seedlings require some form of protection if they are to survive and grow into a productive plantation. Two general approaches for reducing browsing damage to seedlings are to apply chemical repellents and tree guards. Both methods have existed for a long time, and new variations are constantly being developed. Seedling stocking guards, a type of tree guard, are being used operationally in Tasmania, Australia, but there is limited data quantifying their effectiveness and concerns with negative effects on tree performance. Conversely, although proven effective, repellents are not being used, but are potentially cheaper and less problematic. We therefore aimed to determine which is more effective under operational conditions, whether this effectiveness can be improved or extended, and if either treatment has any effects on seedling form or survival. We planted Eucalyptus nitens seedlings with combinations of repellent and stocking guards in six operational plantations to examine and compare their effectiveness. Seedlings were monitored for 12 months to examine treatment longevity. We found that both stocking guards and repellent significantly reduced and delayed browsing severity, with their effects being additive. No negative effects on growth were evident after 12 months, but adverse effects on seedling form warrant further investigation. Both of these methods can be easily and relatively cheaply applied in the nursery before planting, making them appealing options to reduce browsing. However, the ideal method for a given site will depend upon local browsing intensity.

Suitability of acoustics as non-lethal deterrents for macropodids: the influence of origin, delivery and anti-predator behaviour

Context Auditory devices used to deter wildlife are a potentially humane and effective way of minimising deleterious interactions with humans and their livelihoods and have been used successfully for many species around the world. Acoustic cues can be used to manipulate anti-predator behaviour, encouraging animals to forage elsewhere. Employing acoustics derived from natural sources to make use of innate behavioural responses has been suggested to outperform novel or artificial sounds; however, anti-predator strategies vary among sympatric species and will influence the utility of acoustic stimuli for deterring wildlife. Aims We aimed to test the interaction between the source of origin (natural or novel) and species traits (anti-predator strategy – grouping behaviour) on the efficacy of using acoustic stimuli to elicit alarm responses for two species in the family Macropodidae commonly associated with browsing on forest plantation seedlings; the red-necked pademelon (Thylogale thetis) and the red-necked wallaby (Macropus rufogriseus banksianus). Methods We tested these factors in captivity using playback experiments of acoustic stimuli and monitored the behavioural responses of subjects. Results Red-necked pademelons exhibited strong responses to bioacoustic and novel stimuli but did not greatly differentiate among them. Short-term habituation to predator calls was detected whereas responsiveness to novel sounds increased. Red-necked wallabies most strongly responded to conspecific distress calls, showing no sign of short-term habituation. Conclusions Results from the present and other studies suggest that bioacoustic deterrents, particularly those utilising natural conspecific sounds, aimed at communicating danger, have the potential to play an important role in non-lethal wildlife management, although that responsiveness varies with the form of anti-predator strategies employed. Implications If alarm responses translate into subjects vacating targeted areas, then there is some potential to implement non-lethal acoustic deterrents for macropodids alongside other management measures aimed at preventing impacts on primary production. Problematically, our experiments showed that without accurate acoustic delivery, particularly of sounds with infrasonic components, the development of effective bioacoustic deterrents may remain stymied.

Potential for Cleopus japonicus to control the weed Buddleja davidii in plantation forests in New Zealand

Buddleja davidii (buddleia) is an invasive weed in commercial Pinus radiata D. Don plantation forests in New Zealand. For the first time, forestry managers are assessing the potential of a newly established biological control agent to manage B. davidii. Initial releases of the leaf feeding weevil Cleopus japonicus Wingelmüller (Coleoptera: Curculionidae) were made in 2006 at three P. radiata plantations located in cool temperate areas within the North Island in New Zealand. At each site, 1000 adults were released at a central point and their movement monitored along four 150 m transects, radiating outwards from the point of release, for three years. Measurements included the establishment and rates of spread of C. japonicus and damage to B. davidii by the weevils. C. japonicus established at all sites. Feeding damage to B. davidii was strongly seasonal, with damage peaking each autumn, and achieving up to 95% defoliation within three years. A model of adult dispersal probability from the central release point predicted the population front was moving on average 65 m, 42 m and 27 m per annum at each of the three sites. There was an initial time lag of approximately one year between the arrival of the weevil dispersal front, and the agent causing damage of greater than 30% defoliation to B. davidii. Effective B. davidii control needs to occur in the first few years after planting. Our results suggest that C. japonicus could be quite effective at controlling B. davidii during this time if integrated with a complementary weed management technique, such as the spot application of herbicides around plantation seedlings, rather than broadcast application. This would maximize C. japonicus establishment throughout stands.

Characteristics of tree seedlings and neighbouring vegetation have an additive influence on browsing by generalist herbivores

Browsing of commercial tree seedlings by mammalian herbivores can reduce long-term plantation productivity, and is an economic problem worldwide. Characteristics of both tree seedlings and their neighbours can influence browsing on the former, particularly by generalist herbivores. The nature of the combined effects of seedlings and their neighbours is, however, unknown. If effects are additive, it should be possible to exploit the capacity of herbivores to make foraging decisions at multiple scales in order to manage browsing of tree seedlings in forestry plantations. We conducted a field trial that focussed on browsing of Eucalyptus globulus seedlings by native marsupial herbivores. Our aim was to determine the absolute and relative importance of characteristics of both seedlings and neighbouring vegetation on browsing of seedlings. Seedlings with and without a chemical repellent were planted in vegetation patches that varied in the abundance and height of thistles. Browsing of seedlings was assessed over 16 weeks. Characteristics of both seedlings and neighbouring vegetation were shown to influence the degree to which seedlings were browsed, and the effects were additive. Repellent-treated seedlings received less browsing than those without repellent; and browsing decreased with increasing thistle cover. The presence of thistles also increased the time it took for browsers to find seedlings. Results are consistent with the associational plant refuge hypothesis, and vegetation effects may be manifested via an alteration in plant apparency. These results have applications in the forestry industry. They demonstrate the principle that the use of less palatable seedlings combined with tall, unpalatable vegetation can reduce browsing on plantation seedlings in the short-term, and that the effects are additive.

Preferences of two mammalian herbivores for tree seedlings and potential cover crops in plantation forestry

Summary Newly established plantations are often damaged by heavy browsing. This is a major economic problem. Vegetation management involving the use of cover crops is a potential method for reducing browsing damage to plantation seedlings. An important first step in determining whether this is feasible is to determine the relative preferences of browsing herbivores for seedlings and crops. We conducted a no-choice feeding trial with red-bellied pademelons (Thylogale billardierii) and common brushtail possums (Trichosurus vulpecula) to determine their relative preferences for two common plantation species: Eucalyptus nitens and Pinus radiata, and three potential legume cover crops: bitter lupin (Lupinus albus), sweet lupin (L. angustifolius) and broad bean (Vicia faba L. cv Coles Dwarf). Pademelons exhibited a strong preference for P. radiata, but did not eat much of the legumes. Possums showed no significant preferences for any of the plants offered. A paired-choice feeding trial with pademelons demonstrated that bitter lupin was less preferred and oats (Avena sativa variety Esk) were more preferred than E. nitens. These results can now be integrated with an understanding of feeding behaviour at higher scales (e.g. vegetation patch) in order to design effective vegetation management for reducing browsing damage.

Evaluating effects of nursery and post-planting nutrient regimes on leaf chemistry and browsing of eucalypt seedlings in plantations

We examined the effects of nursery and field nutrient treatments on leaf chemistry and browsing during establishment of Eucalyptus globulus (two trials; Cressy and Dunalley) and Eucalyptus nitens (one trial; Tyenna) seedlings. Seedlings had high- or low-fertilizer application treatments in the nursery, were fertilized or not in the field and were individually fenced (used for leaf chemistry sampling) or not (used for browsing assessment). The high-fertilizer nursery treatment resulted in relatively high foliar nitrogen (N) and low tannin content (all seedling types), and high total essential oils (seedling batch planted at Cressy only), but nursery fertilizer level did not affect dry matter, neutral detergent (NDF) or acid detergent fibre (ADF) or lignin. After planting, levels of N, tannins and total essential oils changed over time, but the degree differed between sites. Field fertilizing generally had no effect on leaf chemistry during 10 weeks after planting. Across sites, the pattern of browsing was the same. Seedlings with the high-fertilizer nursery treatment were browsed more than the low-fertilizer nursery treatment, though the difference was only significant at two of the three sites. Thus trends in browsing damage were consistent with differences in foliar N and tannins as a result of nursery- and not field fertilizing treatment. Manipulation of seedling chemistry, using particular fertilizer application regimes in the nursery, may be one tool for managers wishing to decrease seedling damage by browsers, particularly when browsing severity is not extreme.

Tree seed dispersal among forest fragments: I. Conifer plantations as seed traps

AimIn fragmented landscapes, the survival of plant populations may depend on sufficient rates of migration between fragments with which to counteract local extinctions. Empirical information on the plant migration process is limited because of the difficulties of directly measuring the rare medium to long‐distance dispersal events involved. The potential for hardwood tree species' seedlings growing in conifer plantations to offer `a posteriori' measures of intermediate to long‐distance dispersal events was evaluated.LocationFragmented eastern deciduous forest in a rural, agricultural landscape, Southern Ontario.MethodsTo indicate the degree to which plantations `sample' incoming seed, seedling populations were enumerated in plantations and their species composition and abundances compared with those of mature trees, the presumed seed sources, in the surrounding landscape (to 150 m distance). To further quantify the degree to which hardwood seedling populations in plantations represent seed input, seeds of twelve hardwood species were sown in pine plantations and their emergence and early seedling survival monitored for 2 years. A subset of four of these species was planted in hardwood woodlots and their survival compared with survival in plantations to indicate how well seedlings in plantations reflect colonization in deciduous forest fragments.ResultsHardwood seedling populations in plantations comprised the majority of tree species present in the surrounding landscape. Species' seedling abundances were significantly related to tree abundances around plantations. These findings indicate that most hardwood species can establish in plantations and do so in approximate proportion to the amount of seed supplied. All species produced first year seedlings in plantations, but rates of seedling survival were variable, ranging from under 5 to over 40% per species. Large‐seeded species had significantly greater seedling survival than smaller‐seeded species, suggesting that seed size—survivorship relationships could be used to adjust seedling frequencies to measure seed rain. Mean light levels photosynthetically active radiation (PAR) were significantly higher in plantations than in hardwood woodlots, yet rates of early seedling establishment were comparable between plantations and woodlots for four experimentally sown species.Main conclusionsHardwood seedlings in plantations appear to provide reasonable, although conservative, measures of dispersal to forest fragments, albeit with certain qualifications including adjustments for species' establishment abilities.

An Economic Evaluation of Fusiform Rust Protection Research

Abstract Fusiform rust is a widespread and damaging disease of loblolly pine (P. taeda) and slash pine (P. elliottii) in the South. Research has identified families of these pines with improved genetic resistance to the disease, allowing production and planting of resistant seedlings in areas at risk. This study compared the cost of fusiform rust research to the simulated benefits of rust resistant seedlings in plantations that have been or are projected to be established Southwide between 1970 and 2020. Results showed that compounded fusiform rust research costs of $49 million in 1992 will return discounted benefits to plantation owners of between $l08 and $999 million in 1992, at a 4% real discount rate. The most probable targeting of rust resistant seedlings would provide estimated discounted benefits of fusiform rust protection of about $200 to $300 million in 1992, or annual discounted benefits of $40 to $60 million. This would generate benefit-cost ratios of about 4:1 to 6:1 for fusiform rust research. Currently anticipated improvements in resistance will not eliminate all physical and financial damages from the disease; simulation results indicate substantial financial benefits yet remain for additional research and development. South. J. Appl. For. 24(2):77-85.

Damage to and intake of plantation seedlings by captive European rabbits (Oryctolagus cuniculus)

Summary Damage to and intake of three seedling species commonly used in plantation forestry were examined when offered to captive European rabbits (Oryctolagus cuniculus). Rabbits damaged seedlings by clipping them close to the base. Sixty-eight to ninety percent of the stem was removed from all seedlings irrespective of the seedling species. In terms of dry matter intake, rabbits preferred Pinus radiata stem and foliage to that of the other two species, and they preferred Eucalyptus nitens foliage to Eucalyptus globulus foliage. Rabbits consistently removed more foliage and stem from seedlings than they ate, and feeding preferences did not accurately reflect the amount of damage. These results have important implications when considering management techniques to reduce browsing damage through seedling choice. Rabbit damage in plantations may be influenced more by seedling characteristics that affect clipping than those affecting intake.

Effect of herbicides on woody weed control and growth of plantation eucalypt seedlings

Summary Various herbicides were applied to control woody weeds on a granitic soil, before and after planting with open-root and paper-pot seedlings of Eucalyptus regnans F. Muell. and Eucalyptus nitens (Deane et Maiden) Maiden. All herbicide treatments resulted in significantly reduced weed cover during the first six months after planting. For six treatments, weed control effects persisted for at least two years. The growth response of eucalypt seedlings was related to both weed control effects and direct herbicide effects. Post-plant applications of atrazine reduced the survival of paper-pot seedlings. High residual levels of atrazine were associated with growth losses. Lower residual levels of atrazine gave significantly better growth and a direct growth stimulation was indicated. For the study site, atrazine at 4 kg active ingredient ha−1 was an effective and safe herbicide for pre-plant application to plantation seedlings of E.regnans and E.nitens.

Survival and Growth of Outplanted Pine Seedlings after Mycorrhizae Were Inhibited by Use of Triadimefon in the Nursery

Abstract Triadimefon (Bayleton®), applied as foliar sprays at recommended and higher rates to pine seedlings in nursery beds, inhibited development of mycorrhizal roots, but subsequent survival percentages and rates of growth of the seedlings in plantations were not affected.