Sampling indigenous ground‐living beetles in a stand of non‐native tree privet (Ligustrum lucidum) in New Zealand raises new management questions

Small urban forest reserves in New Zealand have been shown to have value in conserving indigenous beetle diversity. However there is little information available on the ability of non‐native vegetation areas such as tree privet to support indigenous beetle assemblages. To investigate this for one site, ground‐living beetles were collected using pitfall traps over a year at a small urban forest of the invasive tree Ligustrum lucidum (tree privet) in Auckland, New Zealand. A total of 815 beetles were found, from 20 families and 42 relative taxonomic units. Using monthly data, there was no correlation between soil moisture and diversity index (P = 0.805) or species richness (P = 0.375). These results raise the question of whether urban patches of non‐native tree privet may have potential as reservoirs of beetle diversity, if only until they are replaced with native vegetation.     

Canopy manipulations of exotic Bitter Willow (Salix elaeagnos) forest for indigenous seedling recruitment: A pilot study

The invasive exotic tree species Bitter Willow (Salix elaeagnos; Salicaceae) has colonised areas of rank exotic grassland and has been found to contain indigenous seed, dispersed by frugivorous birds into the monospecific stands. This small pilot study examined whether indigenous seedlings that have germinated in the understorey of exotic Bitter Willow stands could be stimulated to establish through the creation of small‐scale canopy gaps. In Bitter Willow forest, four single Bitter Willow trees were poisoned to create canopy gaps. Light transmission and seedling regeneration of tree and shrub species were assessed beneath both the four manipulated and three comparable intact Bitter Willow canopies. Over 3 years, seedling height and density increased more beneath opened compared to intact Bitter Willow canopies. These results suggest that Bitter Willow can fill the roles of both a facilitative nurse and a perch tree. Larger‐scale canopy manipulation experiments of both Bitter Willow and other Salix species are needed to determine the full potential of canopy manipulations for forest restoration.     

Regeneration of indigenous trees in Mgahinga Gorilla National Park, Uganda

This study examines the regeneration of indigenous tree species in the formerly encroached area in Mgahinga Gorilla National Park (MGNP), south‐western Uganda. Before gazetting in 1992, MGNP had basically been agricultural land for well over 50 years. The distribution of exotic vegetation was established using a Geographical Positioning System receiver and indigenous vegetation was sampled by establishment of quadrats along transect lines. Observations indicated that approximately 2% of the old cropland was covered by exotic woodlots. Black wattle (Acacia mearnsii) and Eucalyptus trees were found to be the most widely distributed and Pinus patula the least distributed species in the park. Species numbers of indigenous trees (n = 26) were high in the old cropland, compared with twelve species observed in exotic woodlots. The natural forest supported the highest (75%) stem density and the lowest (4%) stem density was recorded in exotic woodlots. Seedling class (< 2 cm, d.b.h.) accounted for the majority of juveniles, with the lowest stem density (1350 seedlings ha^?1) recorded in exotic woodlots compared with 6609 seedlings ha^?1 in the old cropland and 24,625 seedlings ha^?1 in the natural forest. The levels of tree diversity and stocking characteristics recorded under the exotic species suggest that a low diverse community of native species may exploit this environment.     

Spatial dynamics of regeneration in a conifer/broad‐leaved forest in northern Japan

Abstract. This study deals with stand dynamics over a 6‐yr period in a conifer/broad‐leaved mixed forest in Hokkaido, northern Japan. The annual rates of gap formation and recovery were 81.3 m²/ha and 66.7 m²/ha, respectively and turnover time of the canopy was 125 yr. The recruitment processes of the component species in this cool‐temperate forest were governed by different canopy types: gap, canopy edge and closed canopy. Magnolia obovata regenerated in canopy edges, and Acer mono and Prunus ssiori regenerated in canopy edges and gaps. The results suggested that the mosaic structure made up of closed canopy, canopy edge and gap was related to various regeneration niches. Abies sachalinensis had high mortality rates, initiating gap expansion. The transition probabilities from closed canopy or canopy edge to gap for deciduous broad‐leaved trees were lower than for A. sachalinensis, which implies that the difference in degeneration patterns of conifer and broad‐leaved canopies contributes to the heterogeneity of spatial structure in the mixed forests. Spatial dynamics were determined by a combination of gap expansion by A. sachalinensis (neighbour‐dependent disturbance) and gap formation by deciduous broad‐leaved trees (random disturbance).     

A dendro‐ecological study of forest overstorey productivity following the invasion of the non‐indigenous shrub Lonicera maackii

Question: Will a non‐indigenous, invasive, understorey shrub, such as Lonicera maackii (Amur honeysuckle) have an impact on the productivity of overstorey trees in hardwood forests? Location: Trees from 12 invaded and four non‐invaded sites were sampled in hardwood forests of southwestern Ohio, US. Methods: Changes in radial and basal area tree growth in the ten years prior to L. maackii invasion vs. ten years after invasion were examined using dendrochronological techniques. Intervention analysis was used to detect growth changes 25 years prior to and 25 years following invasion, and estimates of load impacts for L. maackii population and biomass were also calculated. Results: We found that the rate of radial and basal area growth of overstorey trees was reduced significantly in eleven out of twelve invaded sites. Non‐invaded sites did not exhibit this consistent pattern of reduced growth. For invaded vs. non‐invaded sites, the mean basal area growth was reduced by 15.8%, and the overall rate of basal area growth was reduced by 53.1%. Intervention analysis revealed that the first significant growth reductions were 6.25 ± 1.24 (mean ± SE) years after invasion with the greatest frequency of negative growth changes occurring 20 years after invasion. In invaded stands, 41% of trees experienced negative growth changes. In terms of invasive load estimates per 1000 L. maackii individuals, radial tree growth was reduced by 0.56 mm.a^?1, and basal area growth was reduced by 0.74 cm².a^?1, Given these findings, significant economic losses could occur in hardwood forests of Ohio. Conclusions: To our knowledge, this is the first study using dendrochronological techniques to investigate the impact of a non‐indigenous, understorey plant on overstorey tree growth. Active management will likely be needed to maintain forest productivity in L. maackii impacted landscapes.     

Use of indigenous ecological knowledge of the Maasai pastoralists for assessing rangeland biodiversity in Tanzania

This paper incorporates the indigenous ecological knowledge (IEK) of the Maasai pastoralists and ecological methods to assess effects of grazing and cropping on rangeland biodiversity at macro‐ and micro‐landscape scales in northern Tanzania. The joint surveys with pastoralists identified indicator plant species and their associations with micro‐landscapes and livestock grazing suitability (i.e. for cattle and small ruminant grazing), while traditional calf‐pasture reserves (alalili pl. alalilia) were evaluated for preservation of rangeland biodiversity. The macro‐landscapes comprising the cool high plateau (osupuko pl. isipuki) and montane forest highland (endim) were included in the survey. At micro‐landscape scales, the osupuko was classified into uplands (orkung'u), slopes (andamata) and dry valley bottomlands (ayarata). The micro‐landscapes were assessed in terms of herbaceous plant species and woody species richness and risks of soil erosion. Biodiversity varied at both the macro‐ and micro‐landscape scales and in accordance with the land‐use types. Greater plant species diversity and less erosion risks were found in the pastoral landscapes than in the agro‐pastoral landscapes. The calf‐grazing pastures had greater herbaceous species richness than the non‐calf pastures, which in turn had more woody species. The study concludes that the indigenous systems of landscape classification provides a valuable basis for assessing rangeland biodiversity, which ecologists should incorporate into ecological surveys of the rangelands in East Africa in the future.     

Composition and distribution of indigenous trees and shrubs as possible criteria for indicating adapted species in semi‐arid rangelands

This study assessed the composition and natural distribution of indigenous trees and shrubs as possible criteria for selecting suitable species for rehabilitation of degraded sites in semi‐arid rangelands. Study sites were identified at Nthangu, Kathonzweni and Kibwezi forests of Makueni County, Kenya using existing vegetation, agro‐climatic maps and Landsat imageries. The sites had mean annual rainfalls of 974 mm, 700 mm and 616 mm, respectively, and moisture indices of 49%, 35% and 32%. Data were collected by establishing sample plots and assessing species counts and diameters at breast height (DBH). Basal area, relative dominance, relative abundance, relative frequency and important value indices (IVIs) were computed for individual families and species at each site. The number of families, genera and species declined from Nthangu (33, 60, 77) through Kibwezi (30, 48, 70) to Kathonzweni (28, 42, 69). Corresponding mean basal areas were 16.7 m² ha^?1, 76.8 m² ha^?1 and 19.3 m² ha^?1. The families Combretaceae, Burseraceae and Mimosaceae were the most important and widely distributed. Based on ecological importance values, candidate species for rehabilitation of degraded sites at Nthangu, Kathonzweni and Kibwezi were Combretum molle and Acacia hockii; Combretum collinum, Commiphora campestris and Acacia tortilis; and Commiphora africana and A. tortilis, respectively.     

杉木林改造成乡土阔叶林对林下植物物种组成和多样性的影响

把杉木林改造成乡土阔叶林,不仅能提供高价值木材,而且能够提升生态系统服务功能,是我国目前改造退化针叶林最常见的经营模式之一,但这些改变对其林下植物物种组成和多样性的影响及机制我们尚知之甚少。以南亚热带杉木林采伐迹地上重新种植的杉木林、红锥林和米老排林为研究对象,调查研究其灌木层和草本层植物物种组成和多样性,结果表明：（1）和杉木林相比,改造后的红锥林和米老排林灌木层的植物物种丰富度和多样性均呈极显著降低（P<0.01）,但其草本层植物只有物种丰富度极显著降低（P<0.01）,多样性均无显著变化（P>0.05）;（2）主成分分析（PCA）表明改造后的林分灌木层和草本层的植物物种组成发生明显的变化,冗余分析（RDA）确定导致林分灌木层植物物种组成发生变化的主要原因是杉木林改造成红锥林和米老排林后的冠层透光率、土壤碳氮比、土壤含水量和凋落物碳氮比的显著变化,而冠层透光率和土壤碳氮比的显著变化是导致其林下草本层植物物种组成发生明显变异的主要因子;（3）方差分解结果显示微地形、乔木特性和土壤理化性质的独立效应对灌木层和草本层植物物种组成的影响高于它们的交互效应。该研究为科学经营管理人工林和提高人工林生态系统多功能性提供科学依据。     

Influence of Colophospermum mopane canopy cover on litter decomposition and nutrient dynamics in a semi‐arid African savannah

The objective of this study was to investigate the influence of mopane canopy cover on litter decomposition in a semi‐arid African savannah. We used a randomized block design with five blocks of 100 × 100 m demarcated in a 10‐ha pocket of open mopane woodland. Litterbags were placed beneath large (8.3 m crown diameter) and small mopane trees (2.7 m crown diameter) and in the intercanopy area. Decomposition was fastest in the intercanopy area exposed to solar radiation (k = 0.35 year^?1), intermediate beneath small trees (k = 0.28 year^?1) and slowest beneath large trees (k = 0.23 year^?1). Soil temperatures beneath small and large trees were 3–5 and 6–9°C lower than in the intercanopy area, respectively. Bacterial and fungal counts were significantly higher (P < 0.05) beneath large than small trees and in the intercanopy area. The amount of N and P released did not vary significantly among sampling sites. Soil moisture in the dry season was similar among sampling sites but rainy‐season soil moisture was significantly greater (P < 0.05) beneath large than small trees and in the intecanopy area. Mopane canopy cover retarded litter decomposition suggesting that photodegradation could be an important factor controlling carbon turnover in semi‐arid African savannahs.     

Roles of dominant understory Sasa bamboo in carbon and nitrogen dynamics following canopy tree removal in a cool‐temperate forest in northern Japan

To clarify the role of dense understory vegetation in the stand structure, and in carbon (C) and nitrogen (N) dynamics of forest ecosystems with various conditions of overstory trees, we: (i) quantified the above‐ and below‐ground biomasses of understory dwarf bamboo (Sasa senanensis) at the old canopy‐gap area and the closed‐canopy area and compared the stand‐level biomasses of S. senanensis with that of overstory trees; (ii) determined the N leaching, soil respiration rates, fine‐root dynamics, plant area index (PAI) of S. senanensis, and soil temperature and moisture at the tree‐cut patches (cut) and the intact closed‐canopy patches (control). The biomass of S. senanensis in the canopy‐gap area was twice that at the closed‐canopy area. It equated to 12% of total biomass above ground but 41% below ground in the stand. The concentrations of NO₃^? and NH₄⁺ in the soil solution and soil respiration rates did not significantly change between cut and control plots, indicating that gap creation did not affect the C or N dynamics in the soil. Root‐length density and PAI of S. senanensis were significantly greater at the cut plots, suggesting the promotion of S. senanensis growth following tree cutting. The levels of soil temperature and soil moisture were not changed following tree cutting. These results show that S. senanensis is a key component species in this cool‐temperate forest ecosystem and plays significant roles in mitigating the loss of N and C from the soil following tree cutting by increasing its leaf and root biomass and stabilizing the soil environment.     

The spatial distribution of beetles within the canopies of oak trees in Richmond Park, U.K.

1. 5054 adult beetles of 144 species were collected in a total of 696 1‐m² collecting trays by knockdown insecticide fogging of 36 different oak trees in closed canopy woodland at Richmond Park, U.K., with three of the trees sampled on each of 12 dates, at 2‐ to 3‐week intervals, between April and October 1984. 2. In late spring (April/May), more individuals and species of beetles were collected in trays close to the trunks of trees than in trays more distant from the trunk. The reverse was the case in late September/October. Neither pattern prevailed in the intervening months. 3. Individual species exhibited a variety of patterns, with some species more abundant near the trunk, e.g. Leiopus nebulosus (L.), Strophosoma melanogrammum (Forster), Cylindronotus laevioctostriatus (Goeze), and Dromius agilis (Fabricius), and some less abundant near the trunk, e.g. Curculio pyrrhoceras (Marsham) and Rhynchaenus signifer (Creutzer). For Adalia decempunctata (L.), this preference changed with season. The observed species preferences for parts of a tree crown near or distant from the main trunk are discussed with reference to their known biologies. 4. No pronounced pattern of preference for north‐ or south‐facing aspects of trees in closed canopy woodland was observed, however populations of some species exhibited patterns of within‐tree distribution that correlate with compass angle; for one species, the ladybird Adalia decempunctata, this distribution changed with season and between colour morphs.     

Effects of wave energy on the residence times of a fluorescent tracer in the canopy of the intertidal marine macroalgae,Sargassum fusiforme (Phaeophyceae)

We determined the relationship between the residence times of water within the canopy of the intertidal macroalgae, Sargassum fusiforme (Harvey) Setchell to the energy caused by hydrodynamic mixing. We measured the residence times (t) of fluorescein dye injected into the canopy (31 ± 9 ind/quadrat; canopy plan form area 6 × 1 m²) to estimate the length of time gametes persist within the canopy. The total kinetic energy (TKE) and wave energy (WE) was measured during dye dispersal, which ranged from 0.002 to 0.009 m²/s² and 0.001 to 0.016 m²/s², respectively. The experiments revealed that the canopy significantly (P < 0.0001) increased t, which was 56 ± 35 s inside of the canopy compared with 14 ± 4 s outside. Moreover, the relationship between t and energy could be statistically modeled with a power function, and for the results inside of the canopy, t = 3.67 TKE^?0.50 for turbulent kinetic energy and t = 1.83 WE^?0.38 for wave energy. Outside of the canopy, t = 0.98 TKE^?0.50 and t = 1.83 WE^?0.38 Based on the values of t determined for within the canopy, we developed a dispersion model to explore how gametes dispersed within the canopy. The estimated dispersion coefficient (D) with respect to WE, could be modeled as D = 403 WE^0.55 and ranged from 10 to 42 cm²/s for the WE examined in the study. Areal gamete densities modeled in the canopy increased in density for increasing WE at short (0.5 h) durations of gamete discharge; however, the relationship reversed above 2 h of discharge.     

The Importance of Ficus (Moraceae) Trees for Tropical Forest Restoration

Forest restoration is an increasingly important tool to offset and indeed reverse global deforestation rates. One low cost strategy to accelerate forest recovery is conserving scattered native trees that persist across disturbed landscapes and which may act as seedling recruitment foci. Ficus trees, which are considered to be critically important components of tropical ecosystems, may be particularly attractive to seed dispersers in that they produce large and nutritionally rewarding fruit crops. Here, we evaluate the effectiveness of remnant Ficus trees in inducing forest recovery compared to other common trees. We studied the sapling communities growing under 207 scattered trees, and collected data on seed rain for 55 trees in a modified landscape in Assam, India. We found that Ficus trees have more sapling species around them (species richness = 140.1 ± 9.9) than non‐Ficus trees (79.5 ± 12.9), and significantly more saplings of shrub and large tree species. Sapling densities were twice as high under Ficus trees (median = 0.06/m²) compared to non‐Ficus (0.03/m²), and seed rain densities of non‐parent trees were significantly higher under Ficus trees (mean = 12.73 ± 3/m²/wk) than other fruit or non‐zoochorous trees (2.19 ± 0.97/m²/wk). However, our regression model found that canopy area, used as a proxy for tree size, was the primary predictor of sapling density, followed by remnant tree type. These results suggest that large trees, and in particular large Ficus trees, may be more effective forest restoration agents than other remnant trees in disturbed landscapes, and therefore the conservation of these trees should be prioritized.     

A new approach for mealybug management: recruiting an indigenous,but ‘non‐natural’ enemy for biological control using an attractant

We previously discovered that (2,4,4‐trimethyl‐2‐cyclohexenyl)‐methyl butyrate (cyclolavandulyl butyrate, CLB) is an attractant for the mealybug‐parasitic wasp Anagyrus sawadai Ishii (Hymenoptera: Encyrtidae: Anagyrini). This wasp is not likely to parasitize the Japanese mealybug, Planococcus kraunhiae (Kuwana) (Hemiptera: Pseudococcidae), under natural conditions. In this study, we showed that this ‘non‐natural’ enemy wasp can parasitize P. kraunhiae in the presence of CLB in field experiments. Laboratory‐reared mealybugs placed on persimmon trees with CLB‐impregnated rubber septa were parasitized significantly more often by endoparasitic wasps than those on non‐treatment trees (18.1–40.3 vs. 0–6.3%). Anagyrus sawadai accounted for 20% of the wasps that emerged from mealybugs placed on CLB‐treated trees. Moreover, CLB attracted another minor parasitoid, Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae: Anagyrini), which also parasitized more P. kraunhiae in the presence of CLB. All wasps that emerged from the mealybugs on control trees were Anagyrus fujikona Tachikawa, a major parasitoid of P. kraunhiae around the test location. These results demonstrated that CLB can recruit an indigenous, but ‘non‐natural’ enemy that does not typically attack P. kraunhiae under natural conditions, as well as a minor natural enemy, for biological control of this mealybug species.     

The role of farm structure on bird assemblages around a Kenyan tropical rainforest

Although it is clear that the farmlands neighbouring fragmented forests are utilized by some forest birds, it is not clear how birds in general respond to farmland habitat mosaic. An effort was made to determine how bird density and foraging assemblages were influenced by farm structural characteristics and distance from forest edge. Thirty farms up to a distance of 12 km around Kakamega forest in western Kenya were studied. Farm structure entailed size, hedge volume, habitat heterogeneity, woody plant density, plant diversity and crop cover. Birds were surveyed using line transects and DISTANCE analyses and classified into six feeding guilds and three habitat associations. Size of farms increased away from the forest, as woody plant density, plant diversity, indigenous trees and subsistence crop cover declined. The most important farm structure variable was hedge volume, which enhanced bird species richness, richness of shrub‐land bird species and insectivorous bird density (R = 0.58, P < 0.01). Bird density increased with tree density while indigenous trees were suitable for insectivores and nectarivores. There were very few forest bird encounters. Agricultural practices incorporating maintenance of hedges and sound selection of agroforestry trees can enhance conservation of birds on farmland, though, not significantly for forest species.     

An appraisal of seed enumeration and videographic techniques for determining seed removal rates by birds

We examined the efficacy of seed enumeration and videographic techniques for determining seed removal by birds from indigenous (Chrysanthemoides monilifera and Olea europaea subsp africana) and alien (Lantana camara and Solanum mauritianum) shrubs at different study sites in the Cape Floristic Region. The seed enumeration technique involved counting the numbers of fruits and associated seeds removed monthly by birds, excluding those naturally abscised, from the shrub canopy. The videographic technique involved visual counts from images of the numbers of fruits and associated seeds consumed by birds over specific time intervals captured by a digital camcorder. Daily seed removal rates by all birds, irrespective of species, measured by both techniques were similar with no significant interactions evident between measuring techniques, site and shrub species. Both techniques displayed higher seed removal from tiny‐seeded S. mauritianum than other shrub species; this was also evident among individual bird species. However, the seed enumeration technique was unable to discriminate between foraging organisms, contamination of traps by wind‐blown fruits abscised from neighbouring branches and fruit theft from the canopy and the traps. In contrast, the videographic technique provided permanent visual and time‐lapse records for individual foraging bird species allowing greater measurement precision and interpretation of fruit removal behaviour by birds. We recommend use of the videographic technique over the seed enumeration technique for studying vertebrates’ seed removal in a detailed manner.     

Characterization of multiple-antimicrobial-resistant Salmonella enterica Subsp. enterica isolated from indigenous vegetables and poultry in Malaysia

Aims: The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables. Methods and Results: Disc diffusion analysis was performed with a selection of 10 different antimicrobial agents. Isolates recovered from indigenous vegetables showed 100% (134/134) resistant to erythromycin and followed by 42%, 34%, 19% for tetracycline, streptomycin and trimethroprim‐sulfamethoxazole respectively. In general, 90·1% (50/55) and 56·7% (76/134) of Salmonella isolated from poultry and indigenous vegetables, respectively, exhibited MAR index more than 0·2. Conclusions: Characterization of Salmonella isolates based on the MAR results indicated that poultry still remains as the main reservoir for multi‐drug‐resistant Salmonella. Four isolates from the indigenous vegetables showed the highest MAR index in this study. Further investigations need to be conducted to determine if Salmonella isolates recovered from indigenous vegetables were gaining more antimicrobial resistance. Significance and Impact of the Study: The study enabled us to determine antimicrobial patterns and trends in Salmonella from poultry and indigenous vegetables in Malaysia.     

High abundance of an invasive species gives it an outsized ecological role

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Past levels of canopy closure affect the occurrence of veteran trees and flagship saproxylic beetles

Aim

Open woodlands are biologically highly diverse habitats, and veteran (i.e., old, senescent) trees are key structures supporting their biodiversity. Open canopy structure had been maintained by both natural‐ and human‐induced disturbances. In the past two centuries, suppression of such disturbances, together with forestry intensification, has turned most lowland woodlands into closed‐canopy forests. We investigated the effect of increased canopy closure on veteran trees and several threatened beetles associated with them.

Location

Floodplain woodlands along the lower Dyje and Morava rivers, Czech Republic.

Methods

We used an approach combining the study of aerial photographs with on‐ground survey of veteran trees and associated endangered beetles. The aerial images were used to obtain the information on historical (1938) and recent (2009) canopy closure in the area of 146 km², where we mapped large oaks (d.b.h. >70 cm), hollow trees and three associated beetles including the hermit beetle (Osmoderma barnabita), the great capricorn beetle (Cerambyx cerdo) and the jewel beetle Eurythyrea quercus.

Results

The presence of large oaks, hollow trees and their associated beetle species are negatively related to recent high canopy closure, and the historical level of canopy closure matters, as in nowadays closed‐canopy stands, the beetles and veteran trees are more common in places that were rather open in 1938 than in the places with closed canopy already in 1938. Moreover, the health state of veteran trees highly depends on the canopy closure.

Main conclusion

The negative effect of canopy closure on veteran trees and their endangered inhabitants is several decades delayed and may thus often go undetected. In the forests, however, large and hollow trees and their associated biodiversity are relics of the past, more open conditions. The restoration of open woodlands is therefore vital for preventing their further decline. Conservation management planning needs to take this into account wherever, veteran trees and associated biota are concerned.

     

Host associations of the strangler fig Ficus watkinsiana in a subtropical Queensland rain forest

Abstract The distribution of epiphytic organisms is limited by the availability of, and dispersal to suitable hosts. We examined the distribution of a hemi‐epiphytic strangler fig, Ficus watkinsiana (Moraceae) in Cooloola National Park (Queensland, Australia), in order to determine whether this species exhibits a preference for certain host species and why. We assessed host bark roughness and flakiness, fruit type, and size to explain the observed distribution of F. watkinsiana. We surveyed over 1900 potential host trees of the 30 most common forest canopy species and found that host size measured by diameter at breast height accounted for most variation in fig prevalence (Binary Logistic Regression log‐likelihood = ?588.178, G = 314.494, d.f. = 1, P < 0.005). After controlling for host size, F. watkinsiana prevalence still differed significantly between host species (χ² = 54.612, d.f. = 24, P < 0.005), a difference that was only partly explained by variation in the bark roughness of host trunks. These results suggest that variation in the rate at which tree species host strangler figs are primarily related to individual tree size – figs may simply be more likely to colonize and thrive upon host species that grow larger.