Immature Trees Research Articles

Distinguishing mature and immature trees allows estimating forest carbon uptake from stand structure

Distinguishing mature and immature trees allows estimating forest carbon uptake from stand structure

Growth Stage-Dependent Variation in Soil Quality and Microbial Diversity of Ancient Gleditsia sinensis.

The environment monitoring of forest is vital for the ecosystem sustainable management, especially soil quality. Ancient Gleditsia sinensis is one of the most distributed ancient trees in Shaanxi. Comprehensive soil evaluate is important for the ancient tree protection. In this study, we selected the most distributed ancient tree Gleditsia sinensis and immature tree to compare the effect of growth stage to soil quality and soil bacteria. Most ancient tree soil nutrients were in good condition compared with immature tree. The bacterial community were composed with Proteobacteria (27.55%), Acidobacteriota (16.82%), Actinobacteriota (15.77%), Gemmatimonadota (6.82%), Crenarchaeota (4.61%), Bacteroidota (4.41%), Firmicutes (4.32%), Chloroflexi (4.28%), Planctomycetota (3.24%) and Verrucomicrobiota (3.04%). The level 2 ancient tree (300-400years old) was different in bacterial community diversity. SOC and STN were important to level 2 (300-400 years old Gleditsia sinensis), and other levels were opposite. Our results suggested that the ancient tree management should not be lumped together.

Reducing conflict between the common vampire bat Desmodus rotundus and cattle ranching in Neotropical landscapes

AbstractIncreased cattle ranching in Neotropical landscapes has led to human–wildlife conflicts that complicate the relationship between agricultural production and biodiversity conservation. We review the literature related to conflicts between livestock production and the common vampire bat Desmodus rotundus, specifically, the factors that influence the incidence of problems caused by bites to cattle. We summarise the strategies proposed to reduce these problems and propose actions from the perspectives of cattle management, landscape ecology and the biology of the common vampire bat. The literature shows that free‐range extensive management systems, where cattle graze in areas with forest cover, near riparian zones, caves, secondary vegetation (generally shrublands and immature trees), and vegetation fragments and edges, increase the implications and the severity of the conflict. As a result of different selection forces, the wing morphology and echolocation characteristics of the common vampire bat facilitate its movement under these landscape conditions, thus favouring a scenario of greater interaction with cattle. We propose the establishment of a ‘buffer zone’ to separate the cattle as far as possible (at least 1 km) from the elements of the landscape that are key for the movement patterns of common vampire bats in cattle ranching areas. The feeding events of this species are positively associated with host availability and landscape elements that provide habitat and connectivity, which shows that the cause of this conflict originates from the process of cattle production and the invasion of the habitat of the common vampire bat. Anti‐rabies vaccination programmes in cattle and forest–cattle separation are the most important strategies to minimise conflict and prevent rabies outbreaks.

Effects of tree sex, maturity, local abiotic, and biotic neighborhoods on the growth of a subtropical dioecious tree species Diospyros morrisiana.

Understanding the drivers of the growth in long-lived woody trees is the key to predicting their responses to and maintaining their populations under global change. However, the role of tree sex and differential investment to reproduction are often not considered in models of individual tree growth, despite many gymnosperm and angiosperm species having separate male and female sexes. Thus, better models of tree growth should include tree sex and life stage along with the abiotic and biotic neighborhoods. We used a sex-specific molecular marker to determine the sex of 2188 individual trees >1 cm DBH of the dioecious tree species Diospyros morrisiana in a 50-ha subtropical forest plot in China. We used long-term census data from about 300,000 trees, together with 625 soil samples and 2352 hemispherical photographs to characterize the spatially explicit biotic and abiotic neighborhoods. We found a male-biased effective sex ratio and a female-biased overall population sex ratio of D. morrisiana. No sex spatial segregation was detected for the overall population, mature, or immature trees. Immature trees grew faster than mature trees and females grew slower than males. Further, conspecific neighbors significantly decreased tree growth, while the abiotic neighborhood showed no significant effect. Our findings suggest that variation in resource allocation patterns within and across individual trees of different sexes and life-history stages should be more widely accounted for in models of tree growth. In addition, our study highlights the importance of sex-specific molecular markers for studying populations of long-lived dioecious tree species.

What state of the world are we in? Targeted monitoring to detect transitions in vegetation restoration projects.

Monitoring vegetation restoration is challenging because monitoring is costly, requires long-term funding, and involves monitoring multiple vegetation variables that are often not linked back to learning about progress toward objectives. There is a clear need for the development of targeted monitoring programs that focus on a reduced set of variables that are tied to specific restoration objectives. In this paper, we present a method to progress the development of a targeted monitoring program, using a pre-existing state-and-transition model. We (1) use field data to validate an expert-derived classification of woodland vegetation states; (2) use these data to identify which variable(s) help differentiate woodland states; and (3) identify the target threshold (for the variable) that signifies if the desired transition has been achieved. The measured vegetation variables from each site in this study were good predictors of the different states. We show that by measuring only a few of these variables, it is possible to assign the vegetation state for a collection of sites, and monitor if and when a transition to another state has occurred. For this ecosystem and state-and-transition models, out of nine vegetation variables considered, the density of immature trees and percentage of exotic understory vegetation cover were the variables most frequently specified as effective to define a threshold or transition. We synthesize findings by presenting a decision tree that provides practical guidance for the development of targeted monitoring strategies for woodland vegetation.

Resolving ecosystem complexity in ecological risk assessment for mine site rehabilitation.

Ecological Risk Assessments (ERAs) are important tools for supporting evidence-based decision making. However, most ERA frameworks rarely consider complex ecological feedbacks, which limit their capacity to evaluate risks at community and ecosystem levels of organisation. We used qualitative mathematical modelling to add additional perspectives to previously conducted ERAs for the rehabilitation of the Ranger uranium mine (Northern Territory, Australia) and support an assessment of the cumulative risks from the mine site. Using expert elicitation workshops, separate qualitative models and scenarios were developed for aquatic and terrestrial systems. The models developed in the workshops were used to construct Bayes Nets that predicted whole-of-ecosystem outcomes after components were perturbed. The terrestrial model considered the effect of fire and weeds on established native vegetation that will be important for the successful rehabilitation of Ranger. It predicted that a combined intervention that suppresses both weeds and fire intensity gave similar response predictions as for weed control alone, except for lower levels of certainty to tall grasses and fire intensity in models with immature trees or tall grasses. However, this had ambiguous predictions for short grasses and forbs, and tall grasses in models representing mature vegetation. The aquatic model considered the effects of magnesium (Mg), a key solute in current and predicted mine runoff and groundwater egress, which is known to adversely affect many aquatic species. The aquatic models provided support that attached algae and phytoplankton assemblages are the key trophic base for food webs. It predicted that shifts in phytoplankton abundance arising from increase in Mg to receiving waters, may result in cascading effects through the food-chain. The qualitative modelling approach was flexible and capable of modelling both gradual (i.e. decadal) processes in the mine-site restoration and the comparatively more rapid (seasonal) processes of the aquatic ecosystem. The modelling also provides a useful decision tool for identifying important ecosystem sub-systems for further research efforts.

Plantain-Tree Rubber Intercropping Systems Improved Productivity in the Tropical Humid Zone of Ghana, West Africa

A three-year field trial was conducted between 2014 and 2017 in the Ellembelle and Jomoro districts of the Western region of Ghana where rubber production is common to determine the optimum population density of plantain when grown in combination with immature rubber tree crops. The trials were arranged in a Randomized Complete Block Design with 3 replications. The treatments were sole rubber, sole plantain, and three intercrops of one row of plantain in between two rows of rubber, two rows of plantain in between two rows of rubber, and three rows of plantain in between two rows of rubber. The rubber clone used was GT1 while the variety of plantain used was false horn. The results showed that population density of plantain had significant effect on the growth of the associated rubber. Growing plantain at closer spacing of 1.5 m under the high-density plantain treatment significantly increased plantain yield compared to the other cropping systems. There was a significant positive relationship between population density of plantain and the rubber tree growth and development. The optimum population density of plantain when intercropped with rubber was 1,666/ha. The study showed intercropping was advantageous over sole cropping for both crops.

KAJIAN HARA DAUN TANAMAN KARET : PERUBAHAN KEBIJAKAN PEMUPUKAN SLOW RELEASE KE FAST RELEASE

The policy change in application of fertilizer type is the common matter in the plantation company. A leaf nutrient content study of immature rubber trees that applied slow release (SRF) and fast release (FRF) fertilizer has been conducted in Sungei Putih Research Centre. The method of this study followed a descriptive-analysis method by comparing the content of N, P, K and Mg on the leaf of immature rubber trees under application of SRF and FRF. The results indicated that N leaf content with SRF application significantly higher (P<0.01) than FRF consecutive 3.15% and 2.93%. The similar circumstance also occurred in P leaf content i.e. 0.25% and 0.19% respectively. Conversely, K and Mg content in SRF application was significantly lower than FRF (P<0.01). K and Mg content was 0.94% and 0.27% in SRF meanwhile in FRF, K and Mg content was 1.2% and 0.33%. The nutrient status of N and P in SRF application was better compared to in FRF. On the other hand the similar condition did not appear in nutrient status of K and Mg. The status of K in SRF application was not better other than FRF application. In the meantime there was no different of Mg status between SRF and FRF application.

Epigenetic and macrophysiological regulation of vegetative progeny crown morphogenesis of Siberian stone pine trees (Pinus sibirica Du Tour, Pinaceae) of different age

The influence of epigenetic (associated with the ontogenetic meristem maturity) and macrophysiological(related to the rootstock influence) factors on the age-related variability of Siberian stone pine crown morphogenesis hasbeen studied. The objects of study are 6-year-old vegetative progeny of juvenile (3–5 years), immature (20–60 years),generative (200–350 years) and senile (350–700 years) trees of different age (grooving in southern taiga subzone, north ofthe Ob-Tomsk interfluve) grafted onto a common young stock. The prevailing trends in the formation of the grafts crownare revealed: the closer the donor tree is to the ontogenetic peak of growth, the more intensively its vegetative progenygrows and branches. The observed differences in growth and branching trends of grafts resulted in the formation of anage-specific crown shape: juveniles slowly grew but actively branched, immature actively grew and actively branched,generative actively grew, but worse branched, senile equally poorly grew and branched.

Spatial distribution and interspecific association patterns between Mansonia altissima A. Chev., Ceiba pentandra (L.) Gaertn and Triplochiton scleroxylon K. Schum. in a moist semi-deciduous forest

Mansonia altissima A. Chev. has an aggregated distribution at the juvenile life stage that becomes random at the mature life stage. Ceiba pentandra (L.) Gaertn could play the role of nurse plant in the management of M. altissima populations providing them a moderate forest shade in large gaps for early growth. M. altissima and Triplochiton scleroxylon K. Schum. displayed independent distribution patterns. M. altissima is a species with economic value found in moist semi-deciduous forests of tropical Africa. The analysis of spatial distribution patterns can help to understand the ecology of this species in forest stands dominated by emergent pioneer tree species like C. pentandra and T. scleroxylon. To assess the spatial distribution patterns of M. altissima and spatial relationships with C. pentandra and T. scleroxylon in their natural habitat. We investigated the spatial patterns of the three species during three life stages; juvenile (immature trees), premature (trees with minimum flowering diameter) and mature (trees with minimum fruiting diameter). Diameter at breast height (DBH) was measured and geographical coordinates of trees were recorded within ten one-ha plots, divided into sixteen subplots (625 m2). We computed the L(r) function, normalized from Ripley’s K(r) function to detect aggregated, random or regular distribution patterns. Aggregations were detected in juvenile and premature M. altissima. Size and scales of spatial aggregation were inversely proportional to the DBH size. M. altissima and C. pentandra displayed interspecific association patterns at the similar life stages. Both species were positively associated within a radius ≥ 3 m. No positive association was detected between M. altissima and T. scleroxylon. Interspecific association patterns between M. altissima and C. pentandra suggest that C. pentandra could be used as a nurse tree in reforestation and management practices of M. altissima populations.

An approach for the formulation of sustainable replanting policies in the Indonesian natural rubber industry

Abstract Rubber replanting is a key factor in sustaining natural rubber supplies because it replaces less productive rubber trees with fully productive ones. However, the time taken for rubber trees to become fully productive (approximately 6 years) can cause significant impacts on shorter-term rubber supplies. In addition, replanting can have environmental impacts, such as reduction of carbon stocks because immature trees convert less CO2 than mature ones, and social impacts, such as reduced need for tappers, the highly skilled employees who harvest latex from rubber trees, during the immature phase of trees’ lives. Early discussions with Indonesian natural rubber stakeholders highlighted a demand for methods and tools that allow the consideration of these impacts when formulating replanting policies. This paper proposes an approach to support the formulation of sustainable replanting policies in the Indonesian natural rubber supply network that allows users to consider trade-offs between three factors: economic, social and environmental. The approach uses the composite indicators method to represent the impacts of replanting on the sustainability of the supply network. These indices are used to drive computer simulations with a view to finding optimal replanting policies for given situations. The approach is illustrated through an application to the formulation of sustainable replanting scenarios in the Langkat, Deli Serdang, Asahan, Simalungun and South Tapanuli Districts at North Sumatera Province Indonesia.

POPULATION STRUCTURE, DISPERSION PATTERN AND SEEDLING GROWTH OF GEWANG PALM (Corypha utan Lam.) IN TIMOR ISLAND, INDONESIA

Food insecurity has been reported to be the top most concern in East Nusa Tenggara (Timor Island) compared to that in other provinces in Indonesia. The use of local species as food sources is one possible arm in the fight against food insecurity. Gewang (Corypha utan Lam.) is a palm species which produces starch similar to the true sago palm (Metroxylon sagu). Although it is important to promote the species as a starch crop, information on its current population and seedling growth performance is still lacking. Hence, a one-hectare plot was surveyed and an experimental plot was established for population and regeneration analyses. In the 1 ha plot there were 31 productive trees, 2 post productive trees, 63 immature trees and 2,211 seedlings. The dispersion of the species followed the clumped pattern for immature trees and seedlings, but shifted to random pattern at maturity or productive stage. The seedling survival was stable when weeded, but dropped to 50% when un-weeded. However, in spite of its stem extraction for starch consumption, the population of C. utan in East Nusa Tenggara was stable. This indicated that C. utan in East Nusa Tenggara is a potential alternative food source to help build food security in Indonesia especially in dry lands like Timor Island and its adjacent regions.

Environmental And Socio-Economic Effects Of Timber Exploitation In Imo River Estuary, Eastern Obolo, Akwa Ibom State, Nigeria

Purpose: This study was carried out to evaluate the environmental and socio-economic effects of timber harvesting as well as to identify the drivers increasing the rate of timber exploitation in Imo River Estuary, Eastern Obolo Local Government Area, Akwa Ibom state, Nigeria.
 Methodology: It was conducted in five Local Government Areas (LGAs) in Eastern Obolo Local Government Area, Akwa Ibom state, Nigeria. A random sampling technique was employed to select a total of 300 respondents composed of 60 randomly selected respondents from each of the five LGAs. A structured questionnaire was used in collecting information from the respondents. Data acquired from the field was subjected to statistical and econometric analysis which included percentages, frequencies, Likert scale rating, exploratory factor analysis, and Chi-square,
 Main Findings: The major finding of this study was that the major cause of timber exploitation in the study area was unemployment, absence of forest regulations, unstable government policies, lack of trained officials, and high cost of timber products. The application of the Factor Analysis Model in this study showed that loss of biodiversity, the disappearance of forest cover, damaging of immature trees and non-wood forest products are the highest environmental effects of timber exploitation in the study area, loading far higher than the stated 0.3 decision score value. Among the social effects, high cost of farm labor is the most severe of social effects in the study area, while the increased cost of wood and forest product and high cost of living ranked highest among the economic effects.
 Applications: The study will be of great importance to environmental policy makers, conservationists, researchers, and Geographers in Nigeria. It will contribute significantly to knowledge build-up in relation to restoring the sanctity of threatened forests in Southern Nigeria.
 Novelty/Originality: The Niger Delta region of Nigeria where this study was carried out is often synonymous with militancy and the problems of environmental pollution. However, this study veers from these already known challenges to peculiar drivers of the depleting forests in this area. The study, therefore, will contribute to the scanty literature related to the subject matter within the study area.

Upward expansion of distribution ranges of tree species: Contrasting results from two national parks in Western Carpathians

We analysed the distribution of trees along the elevation gradient in two national parks located in the Western Carpathians (49°30′–49°37′ N; 19°28′–20°15′ E), dominated by natural forest stands to answer two questions: do immature trees occur at higher elevations compared to mature ones? Has the upper limit of the distribution of the seedlings increased during the period under study, and were the changes proportional to the increase in the mean annual temperature in that period? Data used in our study had been collected in permanent sample plots, distributed regularly over the entire forest area in two national parks. The measurements were taken twice, separated by at least 12 years. We analysed the upper distribution range of the most abundant tree species following tree ontogenic stages for two measurement times. The analysed tree species showed contrasting patterns of the distributions of saplings related to the distributions of mature individuals. In one of the national parks, two species (Silver fir and European beech) showed a significant upward expansion. As three measurements were taken in this park, we found that the expansion has increased over time. In the second national park, located only 45 km to the west from the first one, we found no upward expansion in the distribution of both European beech and Silver fir, while Sycamore maple showed a slight downward trend. We conclude that the dynamics of the tree distributions along the elevation gradient in the mountain areas do not follow a uniform path; the indirect effects of changes in environmental conditions may produce different patterns, reflecting the complex nature of the interactions shaping the distributions of the trees.

Preference and performance of Lepidoptera varies with tree age in juniper woodlands

1. As trees age, they undergo significant physiological and morphological changes. Nevertheless, tree ontogeny and its impacts on herbivores are often overlooked as determinants of plant–herbivore population dynamics and the strength of plant–herbivore interactions.2. Juniperus (Cupressaceae) is a dominant, long‐lived conifer that serves as the sole host to a specialised assemblage of caterpillars. Over the past 150 years, several juniper species in western North America have expanded their geographic occupancy at local and regional scales, which has resulted in an increase in the number of immature trees on the landscape. Using assays in the laboratory, the effects of tree ontogeny on caterpillar performance and oviposition preference for two juniper specialist caterpillars, Callophrys gryneus (Lycaenidae) and Glena quinquelinearia (Geometridae), were examined. The study considered whether responses to tree ontogeny were consistent across caterpillar species and juniper host species.3. Tree age was found to be a reliable predictor of caterpillar performance, with caterpillars developing more quickly and growing larger when fed foliage from young trees. Differences in the phytochemical diversity between foliage from trees of different ages might help to explain observed differences in caterpillar performance. Interestingly, the specialist butterfly, C. gryneus, displayed an oviposition preference for foliage from old‐growth Juniperus osteosperma trees, despite the fact that larvae of this species performed poorly on older trees.4. It is concluded that young juniper trees are an important resource for the specialised Lepidopteran community and that tree ontogeny is an important component of intraspecific variation, which contributes to the structure of plant–herbivore communities.

Bacterial canker of cherry trees, Prunus avium, in South Africa

In the 1980’s the causal agents of bacterial canker of cherry trees in South Africa was reported to be Pseudomonas syringae pv. syringae and Pseudomonas syringae pv. morsprunorum. Subsequently, no further studies were undertaken on the disease or causal agents. The aim of the current study was to conduct field surveys to determine the current situation pertaining to bacterial canker in the major cherry producing areas of South Africa. Following isolations from infected trees, strains were characterized using biochemical as well as multilocus sequence analyses (MLSA). Pathogenicity tests were undertaken with immature cherry fruit as well as three different cherry cultivars. Although symptoms of bacterial canker were present in all areas surveyed, P. syringae isolates were only isolated from three sites in the Western Cape Province. The isolates collected in this study showed a hypersensitive response on tobacco leaves and were pathogenic on immature cherry fruit and cherry trees. The phenotypic tests and MLSA using four genes (cts, gapA, gyrB and rpoD) showed phenotypic and genetic identity with Pseudomonas syringae pv. syringae. Selected strains induced a hypersensitive response on tobacco leaves and were pathogenic on immature cherry fruit and green cherry tree shoots. The current study shows that P. syringae pv. syringae is responsible for bacterial canker in the Western Cape Province, South Africa.

PENGARUH TANAMAN SELA SORGUM MANIS TERHADAP PERTUMBUHAN TANAMAN KARET BELUM MENGHASILKAN

The Land between row of immature rubber period has a potential to produce sweet sorghum. This sorghum is one of high value commodities for food and energy security due to its wide adaptation. The objective of this research were to study the effect of rubber+sorghum intercropping system on the growth of immature rubber trees and to study some agronomic parameters of sorghum and production of sweet sorghum as rubber intercrops. The experiment was conducted at the Sembawa Research Station from June to October 2013. The experiment was carried out as a single factori using Randomized Block Design with three replications. The treatment were 3 varieties of sorghum i.e: Pahat, Kawali and Mandau. Observation of rubber trees was conducted using simple random sampling method, comparing the rubber trees growth of sorghum intercropping system with the rubber trees growth of monoculture system. The results showed that sorghum had a positive effect on the growth of rubber tree IRR 118. Furthermore, fresh stem weight (37.11 t/ha), juice yield (1.80 t/ha), and grains yield (2.69 t/ha) of sweet sorghum Kawali higher than that of the varieties tested. The Kawali has a high potential to produce a biofuel because it had a highest fresh stem weight and juice content.

Deciduous tree species classification using object-based analysis and machine learning with unmanned aerial vehicle multispectral data

ABSTRACTObject-based image analysis and machine-learning classification were applied to multispectral camera array data acquired by a small rotating blade unmanned aerial vehicle (UAV) over a hardwood forest in eastern Ontario. White birch, aspen, and two species of maple were surveyed in the field. Images were segmented and the resulting objects were visually confirmed to correspond with the sampled tree crowns. Following the application of machine-learning classification using the Random Forest algorithm, an independent validation sample of 23 tree crowns was, overall, approximately 78% correct. Aspen and birch were the most distinct species; the two maples appeared to be confused with each other and with immature trees and understory shrubs. Classification accuracy, commission errors, and variable importance were interpreted to be consistent with experience documented in aerial photointerpretation selection and elimination keys for northern hardwoods. Additional tests are recommended to more fully analyse the accuracy of deciduous tree species classification using digital analysis of high spatial resolution multispectral UAV imagery.

Analysis of Exploitation of Forestry Biomass by Industrialization: Effect of Harvesting and Taxation

A control strategy for the conservation of forest biomass is proposed using the system of ordinary differential equation. For system dynamics, we have chosen four state variables in which first three stages are linked up to forest biomass via immature, semi-mature and mature trees and forth industrialization. It is assumed that industries harvest semi and mature phases of the forestry (trees) biomass. Analytically studied the local and global stability of steady state as well as the harvesting policy around the interior steady state. For conservation purpose, we have obtained optimal path considering tax as a control strategy to limit the harvest of trees. In particular, optimal control path is obtained using Pontryagin’s maximum principle. To corroborate the results, we have done numerical simulations for a different set of parameters and shown the various behavior of the system. Further, we have likewise noticed that there are certain parameters which are extremely sensitive to the coexistence state. Sensitivity analysis is done using normalized forward sensitivity index.

Do predator energy demands or previous exposure influence protection by aposematic coloration of prey?

Growing evidence exists that aposematic and toxic prey may be included in a predator’s diet when the predator experiences physiological stress. The tree sparrow Passer montanus is known to have a significant portion of aposematic and toxic ladybirds in its natural diet. Here, we present experiments testing the attack and eating rate of the tree sparrow toward the invasive aposematic harlequin ladybird Harmonia axyridis. We wondered whether the sparrow’s ability to prey on native ladybirds predisposes them to also prey on harlequin ladybirds. We compared the attack and eating rates of tree sparrows of particular age and/or experience classes to test for any changes during ontogeny (hand-reared × young wild-caught ×adult wild-caught) and with differing perceived levels of physiological stress (summer adult × winter adult). Winter adult tree sparrows commonly attacked and ate the offered ladybirds with no evidence of disgust or metabolic difficulties after ingestion. Naïve and wild immature tree sparrows attacked the ladybirds but hesitated to eat them. Adult tree sparrows caught in the summer avoided attacking the ladybirds. These results suggest that tree sparrows are able to cope with chemicals ingested along with the ladybirds. This pre-adaptation enables them to include ladybirds in their diet; though they commonly do this only in times of shortage in insect availability (winter). Young sparrows showed avoidance toward the chemical protection of the ladybirds.