Some effects of orchard soil management on sward composition,levels of available nutrients in the soil,and leaf nutrient content of mature ‘Golden Delicious’ apple trees

The effects of soil management practice on sward composition, the levels of available nutrients in the soil and leaf nutrient content of 11-year-old ‘Golden Delicious’ apple trees were examined over a 3-year period. The treatments consisted of: (a) grass sward mown at either 9 cm or 18 cm high, or controlled with the use of grass suppressant maleic hydrazide; (b) total herbicide coverage using simazine/paraquat or terbacil; (c) clean cultivation.Within the tree rows, beneath the tree canopies, the sward was composed of a higher percentage of weeds and grass and a lower percentage of clover than the sward in the alleys. In both areas, the magnitude of the clover component in the sward was in the order: grass suppressant > short grass > long grass. Over the 3 years, the mean dry-matter yield of herbage clippings returned was 11 938 kg ha^?1 year^?1 in the long-grass treatment, and 9089 kg ha^?1 year^?1 in the short-grass treatment. This was reflected in the higher amounts of mineral nutrients returned in the herbage clippings from the former treatment.In general, the surface soil (0–10 cm) from grassed plots contained more exchangeable Ca and Mg and less NO₃-N than that from the non-grassed plots. Available P accumulated in the surface layer of the herbicide-treated plots. No significant differences in available nutrients were detected below 10 cm soil depth. Over the 3 years, soil management practice had no measurable effect on tree growth or crop yield. However, in the second and third seasons, trees from grassed plots tended to have lower leaf total N contents than those from non-grassed treatments, while trees from cultivated plots tended to have lower leaf K levels than trees from other plots.     

Beschreibung des Feuerbrandbefalls am Institut für Obstzüchtung in Dresden-Pillnitz im Jahr 2003

The orchard of the Institute of Fruit Breeding of the German Federal Centre of Breeding Research on Cultivated Plants in Dresden-Pillnitz was highly affected by fire blight in 2003. Infected pomefruit trees were observed over a period of nearly 3 months. The first symptoms on pear trees were found on May 19th. The pathogen Erwinia amylovora was confirmed officially on May 26, and the last infected apple trees were detected the 11th of August. The infected trees had to be grubbed at the decision of the Phytopathological Authority. In total, 1164 apple and 478 pear trees were grubbed, including the entire pear collection of the gene bank. Of 35 wild species of pear, 49 accessions, eight accessions of six species each, showed infections. The apple collection of the gene bank included 33 wild species, with 365 accessions, and 845 cultivars and clones. Ten accessions of nine wild apple species and 81 cultivars/clones of these collections showed fire blight infection. The source of infection was the pear collection, and the distance from that source was important for the occurrence of infection. Field plots close to the pear collection had tree losses of 10–34%, while more distant plots had losses of 0–6%. Around 80% of the lost apple trees were detected and grubbed from 27th May to 11th June. Some of the cultivars bred in Dresden-Pillnitz, e.g. ‘Pilot’ and ‘Rekarda’, were affected by fire blight in most field plots, whereas most others were affected mainly only in plots adjacent to the infection source. A correlation of r=?0.72 could be calculated for rating in artificial shoot inoculations and percentage of trees of resistant cultivars lost. The cultivars ‘Pirol’, ‘Reanda’, ‘Remo’, ‘Rene’, ‘Renora’, ‘Resi’, and ‘Retina’ showed only a very low numbers of infected trees. No tree of ‘Rewena’ showed symptoms of fire blight. Despite a tendency to postblooming, only 8.9% of ‘Pinova’ trees had to be grubbed.     

Potential use of pervious concrete for maintaining existing mature trees during and after urban development

During the development of parking lots and pedestrian areas, mature trees are often removed from the site and replaced with saplings after development is completed. This research aims to study the possibility of using pervious porous concrete as an alternative pavement that may help to keep existing mature trees, and all the benefits they can provide, alive after site development. Three different pavement treatments: (1) no pavement; (2) impervious standard concrete; and, (3) pervious porous concrete were compared over 2 years to test their ability to modify growth and leaf gas exchange of existing 15–18-year-old American sweetgum (Liquidamber styraciflua) trees. Soil water and temperature dynamics of the pervious plots were closely correlated with those in the control plots. Plots treated with pervious concrete had greater soil water content than plots with standard concrete in the deeper soil layers in some seasons, but not during the summer. Tree diameter (dbh) relative growth rates were similar across the three pavement types. There was no effect of the treatments on leaf water potential or leaf gas exchange. The data presented in this paper suggest that pervious porous concrete does not provide additional benefits in ensuring growth and survival of pre-existing mature trees in new urban developments.     

Evaluating restoration success of a 40-year-old urban forest in reference to mature natural forest

We assessed whether forest restoration was successful in Expo ’70 Commemorative Park in Osaka Prefecture, Japan, which was planted in the 1970s with native late-successional tree species. Detailed survey and analysis of species composition, stand vertical stratification, and forest dynamics, including comparison with a reference, natural late-successional forest, were conducted. The restoration plots had grown to larger basal area compared with the reference plots, however, this was a consequence of very high densities of the overstory trees due to low self-thinning rate. Stand vertical structure of the restoration plots was biased toward overstory layers, causing high mortality of understory trees and shrubs. Because there are no mature forests near the restoration site that could act as a seed source, abundance and diversity of understory trees are likely to continue decreasing in the restoration plots, resulting in single-layered forest structure similar to those of monocultures and even-aged forests. Many seedlings of exotic species emerged in the restoration plots and this could lead to a plagiosere where exotic species dominate the vegetation inhibiting regeneration and growth of native species. Ordination analysis using different measures, basal area and abundance, showed apparently contradicting results, suggesting that multiple criteria are needed to evaluate forest restoration success. Our results indicate restoration of mature, late-successional forest cannot be achieved by simultaneous planting of native species. To sustain urban forests into the future, we must conduct long-term monitoring and management referencing natural forest structure and dynamics.     

Short-term effects of changes in soil management and nitrogen fertilizer application on ‘Bramley’s Seedling’ apple trees.

Soil managment in a ‘Bramley’s Seedling’ orchard, established in a system of herbicide treated tree rows and mown grass alleys, was changed to provide three treatments: complete grass cover, overall herbicide and a continuation of the existing system. Differential rates of N fertilizer (nil, 62.5 kg ha-1) were applied to each soil management regime. In comparison with herbicide strips, complete grass was intensely competitive, particularly with nil application of N fertilizer, reducing tree growth and yield and greatly decreasing leaf N. Leaves from trees in complete grass (nil N) plots contained higher concentrations of P, K and B but lower ones of Ca, Mn and Cu. Compared with the change from herbicide strip to complete grass management, effects of changing to overall herbicide were smaller. There were slight increases in leaf N concentration but no increases in tree growth or fruit yield. Leaf Mn concentration was increased in overall herbicide. Although application of N fertilizer to grass plots increased leaf N concentration by 0.4% and the three-year girth increment, yield was less than that of trees in herbicide strips. Nitrogen fertilizer applied to herbicide strips or overall herbicide plots slightly increased leaf N content but there was no effect on yield or girth increase. Applying N fertilizer to complete grass plots reduced the concentration of P, K and B in leaves but increased leaf Ca, Mn and Cu.     

Effect of tree and branch thinning on growth,yield, and fruit quality of persimmon trees in a high-density orchard

A study was conducted to evaluate the effect of branch and tree thinning on growth, yield and fruit quality in 8-year-old non-astringent persimmon (Diospyros kaki L.f.) trees in a high-density orchard over 6 years in Korea. Adjacent trees in the rows were removed in 2008 (first-year thinning) or in 2010 (gradual thinning). Trees in the second treatment also had 25% of the main scaffold branches removed in the first two seasons. Control plots were left unthinned. First-year thinning elevated leaf macro-nutrient concentrations, increased the production of short fruiting shoots (less than 20 cm) per tree, decreased water sprout development and weight of pruned biomass, and increased fruit set compared with values recorded on control trees and with gradual thinning. First-year thinning gave higher photosynthetic photon flux in the centre of the canopy and better fruit quality. There were generally only small differences in total yield across the three treatments in individual years, but much higher total marketable yield from 2010 to 2013 in the first-year thinning plots. First-year thinning improved overall tree productivity, and the gross returns were 80% higher than those of control from 2008 to 2013 when the extra cost of the thinning was taken into account.     

Light studies in a spacing trial with apple on a dwarfing and a semi-dwarfing rootstock

Light interception by the orchard canopies in a spacing trial with Golden Delicious and Jonathan on M IX and on M II was measured in 1968, 1969 and 1970. In 1969 and 1970 light distribution over the Golden Delicious hedges in the high-density plots was also measured and related to fruit and foliage distribution and to fruit quality. Simultaneously, integrated light readings at 100–200 locations were taken over 24-hour periods, using a photochemical method.Although all plots attained their ceiling yield level in 1967, the 6th year after planting, light interception continued to increase from 1968 to 1970. In the low-density plots — 1100 trees per ha on M IX and 660 trees per ha on M II — the canopies intercepted roughly half of the incident light and yields levelled off at 40 tons per ha. The high-density M IX plot (3300 trees per ha) intercepted two-thirds, the high-density M II plot (2260 trees per ha) more than three-quarters of incident light. Both plots yielded more than 70 tons per ha in 1967 and 1968, but thereafter the yield level dropped, especially for trees on M II, presumably because of mounting inter-tree competition for light.Light levels in the hedges in the high-density plots at equal distances from the hedge perimeter were very much the same for both varieties, for both rootstocks and in the two years. Light levels fell sharply towards the interior and bottom parts of the hedges. The main advantage of the M IX hedge was its smaller cross section, leaving little room for a poorly illuminated centre. At lower light levels weight per fruit and especially fruit colour declined, but the relation between light level and fruit quality was not consistent for both rootstocks and in both years. These inconsistencies could be explained on the basis of differences in pruning system, affecting the type of wood on which the fruit is borne.Fruit was concentrated in the interior part of the hedges, so that a high proportion of the crop suffered from the poor light conditions in this part. Fruit distribution was generally correlated with foliage distribution. In the M IX hedge by far the highest leaf density was found in the centre of the hedge. This is an advantage in comparison with the large leaf area — relatively unproductive and casting much shade — in the top of the M II hedge. Light measurements before and after fruit removal suggested that the shade cast by the fruit is negligible as compared to shading by the foliage.It is concluded that canopy architecture in the high-density M IX plot, with a leaf area index of 2.15, is close to the optimum for single row planting systems in Northwest Europe. Gains in percentage light interception, as in the high-density M II plot, are associated with a greatly inferior light distribution over the canopy, leading to lower yields per unit growth and deterioration of fruit quality. In addition to light, pruning strongly influences fruit quality.     

A Bolting-Resistant Strain of Detroit Beet

The importance of the fungicide used for Apple Scab control in affecting the development of harmful populations of the Fruit Tree Red Spider Mite, Metatetranychus ulmi (Koch), has been noted by Gilliatt (1935), Cutright (1944) and Pickett et al. (1946). The advent of the relatively specific organic fungicide glyodin (Chandler and Thurston, 1949) offered a hope of scab control with a minimum of side-effects on arthropod populations and hence of assessing the role of predators in the control of M. ulmi. In a preliminary trial in Kent (Collyer and Kirby, 1955), on plots sprayed with one or another of four fungicides in 1951–3, higher populations of M. ulmi developed following lime sulphur sprays than after glyodin or captan ; wettable sulphur gave an intermediate result. Conversely, higher populations of predacious mites (Typhlo- dromus spp.) were present on glyodin- or captan-treated trees than on trees receiving lime sulphur. No apparent differences in populations of predatory insects resulted from the four fungicide treatments, and the tentative conclusion was drawn that in this experiment these insects were less likely than the predacious mites to be a cause of the markedly different M. ulmi populations. However, as the plots were small and the trees very close, any differences in insect numbers caused by the treatments would soon be adjusted. A second large-scale trial was made at a more suitable site at Mellow Purgess Farm, Stondon Massey, near Brentwood, Essex in 1952–6, where plots were much larger, allowing several guard rows, and the trees were much younger and smaller, facilitating thorough spraying and representative sampling. Also, this relatively isolated orchard had received very few spray applications in the past and had never suffered from mite infestations at an economic level; Typhlodromus mites and several insect predator species were already present.     

Soil pH in fruit trees in relation to specific apple replant disorder (SARD). II. The first five years at the Wageningen research plot

Field plots were established with 4 target pH values, viz. 4, 5, 6 and 7, to study the effect of pH on specific apple replant disorder (SARD). The target pH levels were not stable and frequently showed fluctuations. Although no significant differences have been found on tree performance, the development of the trees on the plots with the lowest pH level was better than those at higher pH levels.     

Phenology and drought affects the relationship between daily trunk shrinkage and midday stem water potential of peach trees

Summary

The relationship between maximum daily shrinkage in trunks (MDS), daily trunk growth (DTG), predawn water potential (Ψ_pd) and midday stem water potential (Ψ_stem) were studied in an irrigation experiment in peach trees. Control trees were irrigated to replace evapotranspiration, with trees receiving regulated deficit irrigation (RDI) watered at 35% of this rate during Stage II of fruit development and after harvest. The RDI trees were watered as controls during Stage III of fruit development. Minimum (Ψ_pd and Ψ_stem fell to –0.6.MPa and –1.2 MPa, respectively in RDI plots compared with –0.2 and –0.6 MPa in the controls. Trunk growth was less in the RDI plots than in the controls during drought. In contrast, MDS was higher when deficit irrigation was applied in the RDI trees. When site differences were considered the correlation between (Ψ_pd and accumulated trunk growth over an ample period was loose, while maximum daily shrinkage and midday stem water potential remarkably improved such a correlation. However, pooling all available data, the correlation between Ψ_stem and MDS was very poor (R²=0.44) and it substantially improved only when using data from specific phenological periods (i.e. R²=0.75). A seasonal drift in MDS values was observed and it was related to the seasonal changes in trunk growth rates, (i.e. highest shrinkage was found when growth rates were lowest). We concluded that phenology in combination with drought reduce the reliability of the water status information obtained from MDS.     

The effect of street trees and amenity grass on urban surface water runoff in Manchester,UK

It is well known that the process of urbanization alters the hydrological performance of an area, reducing the ability of urban areas to cope with heavy rainfall events. Previous investigations into the role that trees can play in reducing surface runoff have suggested they have low impact at a city wide scale, though these studies have often only considered the interception value of trees.This study assessed the impact of trees upon urban surface water runoff by measuring the runoff from 9 m² plots covered by grass, asphalt, and asphalt with a tree planted in the centre. It was found that, while grass almost totally eliminated surface runoff, trees and their associated tree pits, reduced runoff from asphalt by as much as 62%. The reduction was more than interception alone could have produced, and relative to the canopy area was much more than estimated by many previous studies. This was probably because of infiltration into the tree pit, which would considerably increase the value of urban trees in reducing surface water runoff.     

基于AHP法的高职校园植物景观评价——以陕西职业技术学院为例

运用定量植物景观AHP评价模型,依据物种、观赏特性、开花季节、生活类型和空间类型等5个多样性指标对陕西职业技术学院2个校区的植物景观进行了评价,结果表明,2个校区的植物景观水平都为较好等级,并发现了2个校区绿化现状中在开花季节、生活型多样性方面存在的不足,可以通过增加秋季、冬季开花及常绿和落叶针叶树的种类来改善。     

The Residual Effects of Nitrogen,Calcium and Soil Management Treatments on Yield,Fruit Size and Composition of Citrus

A long-term field experiment testing the effects of 4 soil management treatments and 4 levels of ammonium sulphate on Washington Navel and Late Valencia oranges, budded on rough lemon or sweet orange rootstocks, was terminated in 1965. At this stage the difference in crop yield between the worst and best treatments was about 150%; average annual yields for the 4-year period 1962–65 varied from 18.3 to 46.2 t/ha according to treatment. After 1965 remedial N and Ca treatments were applied to restore the experimental area to a uniformly high level of productivity.

For the 2-year period 1968–69, average annual yields from plots previously receiving the 4 ammonium sulphate treatments varied from 39.1 to 44.6 t/ha; uniformity in terms of yield had thus largely been achieved. Slightly less success, however, was achieved in terms of fruit quality.

Lime, applied to counteract soil acidity induced by the previous ammonium sulphate treatments, produced greater responses on tilled plots than on non-tilled plots. The smaller response to lime on non-tilled plots was largely due to citrus roots being close to the surface and able to absorb applied fertilizer P before fixation could occur.

Some trees, receiving a bare-surface chemical weed control treatment and no N since 1947, were in severe decline in 1965 ; however, they were restored rapidly to full vigour by a midwinter application of 255 kg N/ha in 1966. Furthermore, these trees produced high yields in 1968 when the rest of the orchard was in an ‘off’ year, thereby suggesting that suitable annual adjustments to levels of applied N could be a means of limiting or controlling biennial bearing.

Soil management treatments had no significant effect on the size distribution of the fruit, but the nil and highest N treatments, applied until 1965, had an adverse effect on the size grade (63–75 mm diam.) preferred commercially.     

Environmental,historical, and contextual determinants of vegetation cover: a landscape perspective

We formulated and tested models of relationships among determinants of vegetation cover in two agroforested landscapes of eastern North America (Haut Saint-Laurent, Quebec, Canada) that differed by the spatial arrangement of their geomorphic features and intensity of agricultural activities. Our landscape model compared the woody plots of each landscape in terms of the relative influence of environmental attributes, land use history (1958 – 1997), and spatial context (i.e., proximity of similar or contrasting land cover). Our vegetation model evaluated the relative contribution of the same sets of variables to the distributions of herbs, trees, and shrubs. Relationships were assessed using partial Mantel tests and path analyses. Significant environmental and contextual differences were found between the vegetation plots of the two landscapes, but disturbance history was similar. Our vegetation model confirms the dominant effect of historical factors on vegetation patterns. Whereas land-use history overrides environmental and contextual control for trees, herbaceous and shrub species are more sensitive to environmental conditions. Context is determinant only for understory species in older, less-disturbed plots. Results are discussed in relevance to vegetation dynamics in a landscape perspective that integrates interactions between environmental and human influences.     

Tree composition and diversity in relation to urban park history in Hong Kong,China

In densely populated cities that are dominated by concrete buildings, urban parks serve as major green infrastructures for ecological and environmental functions. Trees are one of the important components that support these green infrastructures. Despite plenty of urban parks established in Hong Kong in the last 20 years, knowledge of tree composition and diversity is outdated. There were also no studies that investigated the differences in tree diversity in relation to park history. Therefore, this study aims to identify the temporary changes in tree composition and diversity in Hong Kong, by conducting a plot-based tree survey in 32 urban parks of different ages. Overall, 2801 trees belonging to 181 species were recorded in 319 plots across all the parks. A ridit analysis was conducted and it indicated the mature size of trees were not significantly larger in old parks. However, the linear mixed-effects models and the post-hoc tests suggested that DBH, tree height and the proportion of crown dieback for each class of tree size were greater in the old parks. Moreover, the composition of top-ranking dominant tree species varied substantially, where more ornamental and exotic trees were adopted in new parks. For species richness, the sample-based species accumulation curves of different park age overlapped when the horizontal axis of the curve was scaled by the average number of combined individual trees. When the horizontal axis was scaled by the number of plots, the curve for the old parks was above the curve for the new parks. The differences derived from these two accumulation methods indicated a higher tree density in old parks. For species evenness, both the rank-abundance curves and Rényi diversity curves depicted a similar low species evenness in old and new parks. These results suggested that species diversity remained largely unchanged from old parks to new parks though the dominant tree species varied. Greater attention should be paid to increase the species evenness in all urban parks, increase tree density in new parks and improve tree maintenance in old parks.     

Effect of urbanization and climate change in the rooting zone on the growth and physiology of Pyrus calleryana

It is well known that trees can reduce the urban heat island and adapt our cities to climate change through evapotranspiration. However, the effects of urbanization and anticipated climate change in the soil–root rhizosphere have not been widely investigated. The current study studied the growth and physiology of the urban tree Pyrus calleryana grown in a factorial experiment with or without urbanization and simulated climate change between April 2010 and December 2012 in the Botanical Grounds of the University of Manchester, UK. The study indicated that urbanization and simulated climate change had small but contrasting effects on tree growth and morphology. Urbanization increased tree growth by 20–30%, but did not affect leaf area index (LAI) and showed reduced peak water loss and hence evapotranspirational cooling. Although soil moisture content in the upper 20 cm was higher in the urbanized plots, urbanization showed reduced sap flux density, reduced chlorophyll a:b and delayed recovery of chlorophyll fluorescence (Fv:Fm) throughout the experimental period. In contrast, simulated climate change had no effect on growth but increased LAI by 10%. Despite being more water stressed, trees grown in simulated climate change plots lost more water both according to porometry and sap flow measurements. Simulated climate change increased peak energy and water loss by around 13%, with trees having an average sap flux density of around 170 g cm^?2 d^?1, 40% higher than trees grown in control plots. Our study suggested that transpirational cooling benefit might be enhanced with a longer growth season and higher soil temperature in places such as Manchester, UK in future, but potentially at the expense of photosynthesis and carbon gain.     

Methods of Reducing Crop Variation in Apple Trials

Data are examined from an apple trial over a period of sixteen years during which the trees received no differential treatments. Crops for a varying number of years were accumulated in order to determine how long a period is needed to obtain a low coefficient of variation. Four years were better than two, but six years gave little advantage over four. Covariance by previous crops was useful, two years’ crop being as good as four years’ crop. Adjustment by trunk girth was less successful but could be recommended in conjunction with previous crop. Number of fruits was a more variable record than crop weight. Removing positional variation by analysis of variance did not have a major effect in reducing variation. Where space is available multi-tree plots proved effective since adjacent tree crops are not highly correlated, but covariance adjustment of multi-tree plots was not successful.     

Effects of different organic apple production systems on seasonal nutrient variations of soil and leaf

An organic apple (Malus × domestica Borkh.) orchard was established to study the interaction effects of ground cover management systems (GMS) and nutrient sources (NS) on soil and tree nutrients in the Southern U.S.A. GMS mulches as follows: green compost (GC), wood chips (WC), shredded paper (SP), and mow-and-blow (MB). Across GMS, one of three NS treatments was applied: commercial organic fertilizer (CF), poultry litter (PL), and no fertilizer (NF). GC-treated plots had greater soil solution nitrate concentrations in year 3. GC plots also maintained greater seasonal soil organic matter and macronutrient concentrations during 3 years compared with the other GMS. Seasonal foliar nutrient concentrations grown under GMS in year 3 tended to follow nutrient concentration patterns similar to those observed in conventional apple orchards. GC and WC trees had overall greater leaf area, dry weight, and total foliar nutrient contents in year 3 than the SP and MB trees.     

Fire severity and seed source influence lodgepole pine (<Emphasis Type="Italic">Pinus contorta</Emphasis> var. <Emphasis Type="Italic">murrayana</Emphasis>) regeneration in the southern cascades,Lassen volcanic National Park,California

Rocky Mountain lodgepole pine, (Pinus contorta var. latifolia) regenerates quickly after high severity fire because seeds from serotinous cones are released immediately post-fire. Sierra lodgepole pine (P. contorta var. murrayana) forests burn with variable intensity resulting in different levels of severity and because this variety of lodgepole pine does not have serotinous cones, little is known about what factors influence post-fire regeneration. This study quantifies tree regeneration in a low, moderate, and high severity burn patch in a Sierra lodgepole forest 24 years after fire. Regeneration was measured in ten plots in each severity type. In each plot, we quantified pre- and post-fire forest structure (basal area, density), counted and aged tree seedlings and saplings of all species, and measured distance to the nearest seed bearing tree. There was no difference in the density of seedlings and saplings among severity classes. Distance and direction to the nearest seed bearing lodgepole pine were the best predictors of lodgepole seedling and sapling density in high severity plots. In contrast to Rocky Mountain lodgepole pine, regeneration of Sierra lodgepole pine appears to rely on in-seeding from surviving trees in low or moderate severity burn patches or live trees next to high severity burn patches. Our data demonstrate that Sierra lodgepole pine follows stand development pathways hypothesized for non-serotinous stands of Rocky Mountain lodgepole pine.     

Spatial patterns of a subtropical,coastal urban forest: Implications for land tenure,hurricanes, and invasives

Spatial patterns of tree structure and composition were studied to assess the effects of land tenure, management regimes, and the environment on a coastal, subtropical urban forest. A total of 229 plots in remnant natural areas, private residential, public non-residential, and private non-residential land tenures were analyzed in a 1273 km² study area encompassing the urbanized portion of Miami-Dade County, USA. Statistical mixed models of structure, composition, location, and land tenure data were used to analyze spatial patterns across the study area. A total of 1200 trees were measured of which 593 trees (49%) were located in residential areas, 67 (6%) in public non-residential areas, 135 trees (11%) in private non-residential areas, and 405 (34%) in remnant, natural areas. A total of 107 different tree species belonging to 90 genera were sampled. Basal area in residential land tenures increased towards the coast while private residential land tenures and natural areas had higher species diversity than non-residential areas. Tree height, crown light exposure, and crown area might indicate the effects of past hurricane impacts on urban forest structure. Land tenure, soil types, and urban morphology influenced composition and structure. Broadleaf evergreen trees are the most common growth form, followed by broadleaf deciduous, palms, and conifers. Exotic tree species originated mainly from Asia and 15% of all trees measured were considered exotic-highly invasive species. We discuss the use of these results as an ecological basis for management and resilience towards hurricane damage and identifying occurrence of invasive, exotic trees.