Tree Girth Research Articles

Geoinformatics and Modeling Approaches for Estimating Above-Ground Biomass in the Moist Deciduous Forests of Uttara Kannada, Karnataka, India

The present study aims to estimate Above-Ground Biomass (AGB) in the moist deciduous forests of Mundgod Taluk, Uttara Kannada district, Karnataka, India using a combination of field sampling and remote sensing techniques. AGB was assessed using Sentinel-2A satellite imagery with a spatial resolution of 10 meters. Field data were collected using the Point-Centered Quarter (PCQ) method, it includes measuring tree girth at breast height (GBH), tree height, and canopy density. AGB was calculated using artificial form factor and specific gravity of tree species and further modelled using the Normalized Difference Vegetation Index (NDVI) derived from satellite data. The results showed a significant correlation between canopy density and biomass, with very dense forests exhibiting the highest AGB values. The field-measured AGB was 436.96 t/ha for very dense forests, 259.89 t/ha for moderately dense forests, and 161.67 t/ha for open forests. A linear regression model developed between AGB and NDVI showed a high R² value of 0.91 for open forests, 0.87 for moderately dense forests, and 0.85 for very dense forests. The total area-weighted biomass for the study area was estimated at 8.87 million tons, with 4.79 million tons in very dense forests, 3.44 million tons in moderately dense forests, and 0.76 million tons in open forests. The regression model validation indicated low Root Mean Square Error (RMSE) values, with the moderately dense forests 8.81 t/ha and the in very dense forests 7.54 t/ha. This study highlights the effectiveness of integrating field measurements with remote sensing for rapid, reliable AGB estimation. The approach offers valuable insights into biomass distribution and carbon sequestration potential, providing a scalable method for carbon inventories at state and national levels, contributing to forest management and climate change mitigation efforts.

Influence of Tree Geometry on Growth and Yield of Mungbean (Vigna radiata L.) under Gamhar (Gmelina arborea Roxb.) based Agroforestry System

The experiment was conducted during kharif (June to September) 2022–23 at Rani Lakshmi Bai Central Agricultural University, Jhansi, Uttar Pradesh, India to evaluate effect of Gmelina arborea geometry on the growth and yield of mungbean, tree growth, biomass, carbon storage and assessing the economic feasibility of the agroforestry systems. The experiment was designed for intercropping of one mungbean high yielding varieties viz., IPM 205-7 (Virat) sown in June with Gmelina arborea. The treatments for gamhar and mungbean are as follows: T1-Vigna radiata sole crop; T2-Gmelina arborea sole tree (5×5 m2); T3-Gmelina arborea sole tree (5×4 m2); T4-Gmelina arborea sole tree (5×3 m2); T5-Gmelina arborea (5×5 m2)+Vigna radiata; T6-Gmelina arborea (5×4 m2)+Vigna radiata; T7-Gmelina arborea (5×3 m2)+Vigna radiata. Experiment was designed in randomized block design (RBD) with seven treatments and five replications. The effect of different spacing patterns viz., S1-5×5 m2, S2-5×4 m2, S3-5×3 m2 in 2 year old Gamhar plantation with seven treatments combinations on mungbean was studied at the Forestry Research Farm, RLBCAU, Jhansi. The maximum number of branches plant-1 (8.04), number of trifoliate leaves plant-1 (11.96), number of seeds pod-1 (12.32), grain yield (0.73 t ha-1) and straw yield (2.13 t ha-1) was recorded in mungbean sole crop. The plant height (62.51 cm) was recorded highest in mungbean intercrop in 5×3 m2 gamhar spacing. The maximum girth (27.38 cm) of trees was recorded in 5×5 m2 gamhar spacing mungbean intercrop. The tree height (6.01 m) and benefit cost ratio (2.67) was observed maximum in 5×4 m2 gamhar spacing with mungbean intercrop.

Evaluation of Acid Lime (Citrus aurantifolia Swingle) Genotypes for Growth, Yield and Quality Traits

A study on evaluation of acid lime genotypes for growth, yield and quality traits was carried out at Citrus Research Station, Vannikonenthal, Manur Taluk and Tirunelveli district, Tamil Nadu during the year 2021–2023. Twenty five acid lime genotypes were selected for the experiment. Observation on quantitative traits such as tree height (m), tree spread (m), canopy spread (m2), tree girth (cm), leaf lamina length (mm), number of fruits/tree, mean fruit weight (g), fruit length (cm), fruit girth (cm), fruit volume (cc), number of seeds per fruit, yield/tree (kg) and qualitative traits such as total soluble solids (°Brix), acidity (%), juice content (ml), fruit juice percentage (%) and ascorbic acid content (mg/100g) were recorded. The present study results revealed that genotype SCA 19 recorded the highest values for the traits such as tree height (3.49 m), tree spread (3.58 m2 E-W; 3.74 m2 N-S), canopy spread (6.57 m3), leaf lamina length (58.40 mm) and tree girth (13.66 cm). However, genotype SCA 06 registered the lowest tree spread character. In the case of yield traits, genotype SCA 19 registered the highest values in number of fruits per tree (1080), mean fruit weight (58.75 g), yield per tree (57.89 kg per tree), number of seeds (9.10), fruit length (8.50 cm), fruit girth (4.90 cm) and fruit volume (54.81 cc). Regarding quality traits, SCA 19 observed the highest values viz., TSS (6.71˚Brix), acidity (6.78 %), ascorbic acid content (26.50 mg/100 g), fruit juice percentage (52.1 %) and juice content (46.0 ml). Hence, acid lime genotype SCA 19 recommended for further evaluation in different parts of Tamil Nadu.

Forest carbon stock-based bioeconomy: Mixed models improve accuracy of tree biomass estimates

Tree biomass and carbon stock continue to be the most important contributors to a forest-based bioeconomy. Accurate estimation of tree biomass and carbon stock therefore is crucial for planning a sustainable bioeconomy based on sustained forest bioresource production and harvest. Precise carbon accounting is also of fundamental importance for a green carbon market as well as for an improved model of quantitative global carbon cycle. However, estimating biomass and carbon at a large spatial scale without causing significant environmental disruption has been posing a methodological challenge necessitating to evolve a robust yet accurate estimation method. Although forest-specific generalized allometric models are the most widely used method to estimate forest tree biomass and carbon stock, these either under- or over-estimate the values, particularly in mixed-species forests. To address this challenge, we employed mixed equations that included species-specific models or available models for a sister species that provided a more conservative estimate of stand-level tree biomass and carbon compared to the generalized equations. We gathered primary data on tree girth and height at the stand level from sub-tropical and temperate forests of Tawang river basin, Arunachal Pradesh, India for validation. We compiled 32 equations comprising 27 species-specific and 5 forest-specific generalized models from a global dataset of allometric models. The outputs from the mixed models were comparable with the results of the harvest studies conducted by other researchers in similar forest types validating the efficacy of mixed models at a landscape scale.

Relationship between Tree Girth and Forest Dieback Severity in Horton Plains National Park, Sri Lanka

Forest dieback changes the physiognomy, structure and floristic composition of montane forests leading to deterioration of ecosystem services. Although research has been conducted to investigate the etiology of forest dieback at Horton Plains National Park (HPNP), a direct cause for this phenomenon is yet to be identified. We investigated the relationship of plant maturity with forest dieback in montane forest species at HPNP. Two sites were selected considering the dieback percentages: less than 25% crown dieback as the healthy site and more than 75% crown dieback as the severe forest dieback site. The percentage crown dieback and girth at breast height was recorded in all individuals>10 cm in both plots. The mean GBH varied significantly among different crown dieback categories in five tree species in the healthy site and four tree species in the severe forest dieback site. In the healthy site, the mean GBH of healthy Cinnamomum ovalifolium trees was lower than that of dead trees while in the severe dieback site, it was higher for the severe crown dieback category than the healthy and rare dieback categories. In the severe dieback site, the mean GBH of healthy Symplocos obtusa trees was lower than that of the medium crown dieback category, while the mean GBH of dead Eurya chinensis trees was higher than that of healthy and rare crown dieback categories, in the severe dieback site. Furthermore, low crown dieback percentages were recorded in Syzygium rotundifolium, Vaccinium leschenaulti, and Litsea ovalifolia with the low mean GBH. A lower mean GBH was recorded for dead individuals of Symplocos cordifolia than healthy individuals. More research must be conducted to understand the relationships between forest dieback and site-specific factors to ensure the success of conservation efforts in tropical montane forests at HPNP.
 Keywords: Forest dieback, GBH, Plant maturity, Tropical montane forests

Correlation study in growth parameters of Pongamia (Pongamia pinnata) and physiological parameters of black gram (Vigna mungo (L.) Hepper) in agroforestry system

The present investigation was conducted to study the tree crop interaction considering the Pongamia (Pongamiapinnata) tree morphological characteristics and physiological parameters of black gram (Vigna mungo (L.) Hepper) inagroforestry system. The experiment was conducted during kharif 2019-20 and 2020-21 in "T" block, Agroforestryexperimental fields of University of Agricultural Sciences, Dharwad campus which is located at 15° 26' North latitude and75° 0' East longitude, with an elevation (altitude) of 678 m above mean sea level. Pongamia pinnata provenance's growthand volume observations were recorded. They included tree height, tree girth, canopy cover and number of branches etc.Two years pooled data recorded maximum values in treatment (T1) RAK-1 (Rahuri Karanja-1) + black gram followed by(T9) RAK-9 + black gram which is on par with (T6) RAK-7 + black gram. Lowest values recorded in (T8) RAK-9 + blackgram which is on par with (T4) RAK-4 + black gram. Whereas the growth parameters of black gram like leaf area duration(LAD), absolute growth rate (AGR), crop growth rate (CGR) and dry matter accumulation recorded under Pongamiaprovenances which showed opposite trend because of the fluctuations of light and mutual shading of the crops within or inbetween rows, frequent overcast due to clouds as a common phenomenon during tropical and sub-tropical monsoonscausing regular fluctuation of sunlight. The treatment (T11) sole crop showed the maximum value, followed by (T8) RAK-9 + black gram and (T4) RAK4 + black gram and lowest value was recorded at (T1) RAK-1 + black gram treatment. Solelegumes recorded maximum AGR. CGR, LAD and dry matter accumulation were also found to have highest significantpositive correlation with seed yield.

Assessment of carbon sequestration rate and tree diversity in a model urban green cover study using a college campus in Mangalore city

The extant green cover in a 140-year-old St Aloysius College campus in Mangalore, Karnataka, India, was used as a model to study tree diversity and carbon-sequestering rate (CSR), using a non-destructive biostatistics-based method. The results of the study indicated that the campus constituted a highly diverse tree flora with a Shannon Diversity index of 4.07. A total of 169 different tree species were found on the campus with an average population size of 9.98 per species. The green cover of 4.67 ha of the total area of the campus had a tree density of 361.03 trees/ha. Five tree species, namely Polyanthia longifolia, Cocos nucifera, Tectona grandis, Terminalia catappa, and Areca catechu, dominated the area. Using allometric equations, the total green cover in the campus area with biomass of 4594.6 Kg, which sequestered 8431.1 Kg of carbon at a carbon sequestration rate of 84.31 Kg per year was deduced. Olea europaea and Phoenix dactylifera, with the highest CSR of 0.09 and 0.08, respectively, were the most effective in sequestering 12.54 Kg and 11.19 Kg of carbon. The highest amount of Carbon sequestered (CS) per tree was in Olea europaea (12.54 Kg) and Phoenix dactylifera (11.19 Kg), followed by Acacia auriculiformis (10.44 Kg), and Adenanthera pavonina (10.08 Kg). It was observed that the amount of carbon sequestered decreased with the decrease in tree girth.

Twenty‐five years of change in forest structure and nesting behavior of Hawaiʻi ʻelepaio

Long‐term ecological studies are invaluable for detecting changes over time. Forest restoration has been a conservation priority in Hawaiʻi, where invasive species have negatively impacted native bird habitat. During 1993–1994, a study was conducted of Hawaiʻi ʻelepaio (Chasiempis sandwichensis) nest site selection and forest composition in mesic montane forest along Mauna Loa Road in Hawaiʻi Volcanoes National Park. We returned to the site and repeated the methods used in the earlier study to record Hawaiʻi ʻelepaio nest site selection (tree species, tree and nest height, and tree girth [diameter at breast height, DBH]) from 2015 to 2017, and measured forest composition (tree density, relative abundance, height, and DBH) in 2019. Three times as many nests were found in ʻaʻaliʻi (Dodonaea viscosa) as in koa (Acacia koa) in both time periods. Heights of koa and ʻaʻaliʻi did not change, but their DBH increased over time. The relative height of nests in ʻaʻaliʻi trees did not change, but nests in koa were placed higher in the crown during the later study. Overall tree density increased from 1,619 (95% confidence interval [CI] = 1,499–1,740) trees/ha to 2,583 (95% CI = 2,176–3,096) trees/ha. Koa relative abundance was 53% of total trees earlier and 45% later, ʻaʻaliʻi remained at 47%, and māmane (Sophora chrysophylla) increased from 0 to 8% over time. Our results indicate that changes in forest composition affect nesting behavior, but in ways that are not necessarily simple or consistent.

Structural Characterization of Island Rainforests and Secondary Groves in Southern Nigeria

This study characterized the structural attributes of island rainforests and secondary groves within Orogun region in southern Nigeria. The quasi-experimental design was used, and the vegetation structural characteristics were determined in both secondary groves (experimental sites) and island rainforests (control sites). The randomized systematic sampling was employed in dividing the study area into 6 zones which were selected upon the presence of mature rainforest islands and secondary groves respectively. Six plots were sampled in each ecosystem. Tree heights, tree girths, and plot sizes were the data collected. Both secondary groves and island rainforest plots were measured to first determine uniformity in the area covered by the trees, after which, size of 200 ft X 100 ft was chosen as the uniform area of plot from which data were gathered. Tree girths at breast height were determined using measuring tape; while tree heights were determined by the use of Abney level and measuring tape. The 15.0 version of the Statistical Package for the Social Sciences (SPSS) was used in the statistical tests of the stated hypotheses. Statistical results showed that t-value = 7.05, P(0.001) > 0.05 for tree heights; and t-value = 3.122, P(0.026) > 0.05 for the tree girths. The mean differences in the structural characteristics between the secondary and mature island rainforest were significant at 0.05 alpha level. This implies that trees within island rainforests are significantly taller and bigger. The higher structural attributes of the island rainforest revealed that over time, conservation of rainforest trees could positively impact on its structural attributes. Therefore, ecosystem-based management approach was recommended for the management and conservation of the rainforest trees and covers

Structural diversity is a key driver of above-ground biomass in tropical forests

ABSTRACT Background A gamut of abiotic and biotic factors is related to the amount of above-ground biomass (AGB) produced in ecosystems. Some factors have direct and others indirect relationships with AGB. Detailed analyses in tropical forests are few but much needed for better understanding the potential impacts of global change drivers and for mitigating impacts. Aims Here, we examined the relationship between AGB and different predictor variables and quantitatively evaluated their relative importance in lowland to lower montane deciduous and lower montane – montane evergreen forest types. We hypothesised that the relationship between AGB and climate, topography, structural diversity, species diversity (alpha and beta) and phylogenetic diversity would differ between the two forest types. Methods We inventoried trees from 114 plots (each 0.1 ha) and used partial least square structural equation modelling to test the direct and indirect relationship between AGB and the predictor variables. Results We found that structural diversity variables, stem density and tree girth, were significantly and positively related to AGB in both forest types, displaying a stronger relationship in montane evergreen forests (w = 0.65 for density and 0.89 for tree girth). In the deciduous forest, alpha and phylogenetic diversity were also important factors, whereas beta and phylogenetic diversity were important in the evergreen forest. The effects of topography and climate varied between forest types, with elevation and precipitation being related to AGB directly and indirectly through their relationship with structural diversity. Conclusion Our results suggest that structural diversity is a key driver of tropical forest biomass, both directly and indirectly. This fundamental understanding can aid in the predictive efforts of biodiversity conservation and forest management.

PAT: Phytosociology Analysis Tool

Researchers quantify vegetation characteristics using phytosociology studies. The data collected from vegetation surveys, such as tree girth and height measurements, are used to calculate various phytosociological attributes like frequency, density, basal cover, important value index, etc. In general, they are calculated using an Excel spreadsheet and a lengthy mathematical process. There are a few open-source or free software available to compute some of these parameters. However, they are not user friendly for most researchers. Also, these software primarily doesn’t compute basic phytosociological attributes. In view of these constraints and to ease researchers work, we have developed a simple tool, “PAT” Phytosociology Analysis Tool,” that computes the maximum attributes from the field collected vegetation data. The PAT GUI is simple. PAT computes results using standard formulas after users upload a csv file in the required format. Users can download the table's results and figures in PNG format.

Short-Term Effects of Bokashi Fertilizer with Reduced NPK Fertilization on Soil Fertility, Growth, and Yield of Rubber Trees

Rubber is currently the second major industrial crop in Malaysia after oil palm. The use of bokashi fertilizer (BF) on industrial crops is still not popular, and farmers rely mostly on chemical fertilizers (CFs) that are costly and hazardous to the environment. This research was conducted at Hevea plantation, Universiti Putra Malaysia, between August 2020–October 2021. The study was to assess the short-term effects of BF with reduced NPK fertilization on soil fertility, growth, and yield of rubber. Seven treatments (T) were involved. T1, T2, and T3 denote 4, 8, and 12 kg BF per pit. T4 was 1 kg NPK as control, whereas T5, T6, and T7 denote 4, 8, and 12 kg BF + 500 g NPK per pit, respectively. The variables observed included total nitrogen (TN%), total phosphorus (TP%), organic carbon (OC%), organic matter (OM%), exchangeable cations, microbial counts, tree girth, and dry rubber yield. The major findings indicated that applying 12 kg BF has raised the soil’s TN%, OC%, and OM% by 165, 171.4, and 172.0%, respectively, compared to NPK control. Also, adding 4 kg BF + 500 g NPK has increased the soil’s cation exchange capacity and TP% values by 107.8 and 42.9%, respectively, compared to the control. Adding sole bokashi increased the bacterial population by 22.2–133.3%. Rubber yield was better on trees treated with 12 kg BF, though this did not differ significantly from other treatments. Therefore, applying 12 kg BF or 4 kg BF + 500 g NPK can improve soil fertility and save costs from using inorganic fertilizer by at least 50%.

Changes in Floral Diversity due to Livelihood Pressures in the Eco-sensitive Zone of Nongkhyllem Wildlife Sanctuary in Ri Bhoi District of Meghalaya

The challenges in the management of diverse flora impacted by anthropogenic factors in areas governed by different land tenure systems are enormous notwithstanding lying in a classified biodiversity hot spot region in Meghalaya in North- east India. The attributes of the plant population in protected areas like Nongkhyllem Wildlife Sanctuary (NWLS), Nongkhyllem Forest (NRF), and District Council governed Eco-sensitive zone (ESZ) were studied using Important Value Index (IVI), Shannon’s and Weiner Diversity Index and Sorenson’s similarity index. Shorea robusta C.F.Gaertn., Tectona grandis Linn. L.f., Schima wallichii (D.C.) Korth, had the highest IVI value of 64, 56, 42, etc. respectively, while the diversity index showed maximum values of 0.78 in recorded forest area and minimum of 0.60 under district council area. Similarity index ranged between 16.67 % and 39.22 %. The species richness and diversity in the recorded forest area was higher compared to the forest under the district council. In addition, tree girth and density of other species were determined. The study revealed that the cultivation of betel nut (Areca catechu L.), betel leaf (Piper betle L.), broom (Thysanolaena maxima Kuntze) and banana (Musa spp.) though for livelihood and income generation contributed to vegetation alteration in the district council forest area. Strict enforcement of ESZ laws & creating alternative livelihood opportunities can help minimize biodiversity loss.

Temporal variability in fine root dynamics in relation to tree girth size in sub‐tropical sal (Shorea robusta) forests

AbstractIn forest ecosystems, the rapid turnover of fine roots (≤2 mm in diameter) is a major pathway of carbon and nutrient flow from plants to the soil. This study was conducted to determine how fine root biomass (FRB), productivity (FRP) and turnover (FRT) are affected by site characteristics, seasonal variation, soil depth and tree girth size in sub‐tropical sal forest ecosystem. Four sites (S1, S2, S3 and S4) were established in the Bhabhar region of Nainital istrict, Uttarakhand, India within an elevational range of 405 and 580 m, and at each site, sal trees were categorized into five girth classes. Fine roots were sampled seasonally up to a depth of 60 cm and divided into three layers (0–20, 20–40 and 40–60 cm). FRB was significantly affected by tree girth size and decreased with increasing girth size, while the effect of tree girth on FRP and FRT was observed to be insignificant. Seasonal variation of FRB in all girth sizes showed a keen resemblance as the standing FRB reached its pinnacle during the rainy season and the bottom line in the winter season. Maximum FRB was reported for the uppermost, organo‐mineral‐rich soil depth (0–20 cm) at 1.0 m distance from the tree bole and decreased with increasing soil depth and distance from the tree bole while FRT showed a reverse trend. The present study provided a holistic outlook on variations in FRB, FRP and FRT and the impact of edaphic characteristics and tree girth on fine root dynamics in the sal forest ecosystem of Central Himalaya, India.

Study on morphological characterization of Citrus macroptera Mont collected from garo hills district Meghalaya, India

The work was undertaken to study the variability in Citrus macroptera from five Garo hills district. Many important horticultural plant species, viz. Citrus are known to have originated from this region. Citrus macroptera Mont. is one of the endangered, semi-wild species which have found to exist in various parts of NE region, including Meghalaya. Thirty accession of Citrus macroptera from five different districts of Garo Hills, Meghalaya were collected to study its variability in quantity and quality parameters. In the study significant to highly significant differences were observed among the genotypes. The analysis of variance for different parameters such as tree height, tree girth, leaf length, leaf width, fruit width, fruit length, fruit weight, number of fruit segment, rind thickness, number of seeds per segment, seed length, and seed width varied significantly among accession. Variability among accession collected from different location shows the great scope for genetically potential genotypes for cultivation and also for their exploitation in plant breeding programme.

Variability for Oil, α- and β-santalol Content in Indian Sandalwood (<i>Santalum album</i> L.) from Marayoor Sandalwood Reserve – The Only Natural Population in India

Indian Sandalwood ( Santalum album L.) is categorized as 'vulnerable' by International Union for Conservation of Nature. Marayoor Sandalwood reserve in the Kerala state is the only natural sandalwood reserve in India and perhaps in the world having substantial Santalum album (Indian Sandalwood) trees. Variation for oil and its major constituents i.e., α- and β- santalol of the Sandalwood trees in this reserve has been attempted for the first time. Core samples were collected from trees of different girth size ranging from 30 to 140 cm. The sandalwood oil was extracted from the core samples using solvent extraction method. Oil content ranged from 1.3% to 6.2%. From the extracted oil, α- and β- santalol content was estimated by using Gas chromatography/Mass spectrometry. The α- and β- santalol content varied from 45.17 to 55% and 18.3 to 27% (w/w) respectively. There was no relationship between tree girth, oil, and santalols content. Considerable variation exists in the natural population for oil content and sufficient care has to be taken while selecting superior genotypes.

Fully Polarimetric L-Band Synthetic Aperture Radar for the Estimation of Tree Girth as a Representative of Stand Productivity in Rubber Plantations

This article explores a potential exploitation of fully polarimetric radar data for the management of rubber plantations, specifically for predicting tree circumference as a crucial information need for sustainable plantation management. Conventional backscatter coefficients along with Eigen-based and model-based decomposition features served as the predictors in models of tree girth using ten regression approaches. The findings suggest that backscatter coefficients and Eigen-based decomposition features yielded lower accuracy than model-based decomposition features. Model-based decompositions, especially the Singh decomposition, provided the best accuracies when they were coupled with guided regularized random forests regression. This research demonstrates that L-band SAR data can provide an accurate estimation of rubber plantation tree girth, with an RMSE of about 8 cm.

Functional importance of bird-dispersed habitat for the early recruitment of Taxus chinensis in a fragmented forest

The relationship between bird habitat selection and seed deposition is well established; however, knowledge remains limited on the functional importance of bird habitat for the early recruitment of seed deposition and seedlings in remnant fragmented forests. Here, we evaluated the post-foraging habitat use by birds and quantified the effects of habitat factors on seed deposition and seedling distribution of the endangered Chinese yew Taxus chinensis in a fragmented forest. Birds preferentially frequented fruiting trees for perching (85%, T. Chinensis and Machilus thunbergii trees). Tree cover, height, crown size, and girth were the most important factors affecting habitat use by birds. Consequently, the number of deposited seeds was positively affected by three tree-associated perching traits (girth, cover, and crown size). Seedling distribution strongly overlapped with the distribution of deposited seeds, confirming that seedlings could survive in bird-dispersed habitats. Increasing tree girth, cover, and crown size may enhance seedling recruitment. Our results highlighted the functional importance of large trees in patchy environments for supplying suitable sites for bird habitat use, which also fitted the requirement for early recruitment of T. chinensis. Consequently, protecting remaining large trees in fragmented forests should be considered in forest conservation and management.

Tree girth increment pattern in three medicinally important Pterocarpus species in Kerala, India

Pterocarpus indicus Willd., Pterocarpus marsupium Roxb., and Pterocarpus santalinus L.f. are commercially important medicinal trees, which are also having conservation concern and listed under the IUCN Red list of threatened category. However, information is not available on their tree girth increment pattern. In the present study, species-wise data pertaining to GBH (tree girth measured at 1.37 m from ground level) of trees were periodically collected till they attained the age of 34 years from the species trial plots established in 1984. The mean annual increment in GBH at 34 years was maximum in P. marsupium, followed by P. santalinus and P. indicus with no significant difference in the values of P. indicus and P. santalinus. The relation between tree age and the mean GBH of all the three species were modeled using simple linear regression models which have significant coefficients of determination (R2). Thus, the fitted equations can be used for estimating the tree age from the GBH of standing tree.

Genetic parameters in a clonal test of Tectona grandis in Mato Grosso, Brazil

Teak (Tectona grandis) is a high-value timber species in tropical regions. In Brazil, although teak has a high productivity, there are few studies related to its genetic improvement. This work aimed to estimate genetic parameters and evaluate potential gains of selection in a clonal test of teak installed in the state of Mato Grosso, Brazil. The experimente is in a randomized block design, with five replications, 3x3 m spacing, 22 treatments, and plots with six individuals. At five years, the genotypes were evaluated for survival (S), tree total height (H) and girth at breast height (GBH). There was significance and feasibility of selection for S and GBH. For H, the result was not significant, indicating few gains with the selection. The genetic parameters of clonal mean heritabilities and accuracy were of moderate magnitude for S and GBH and low for H. To best of our knowledge, this is the first work that estimates genetic parameters in a clonal teak test in the field in Brazil.