Limestone Forest Research Articles

Responses of Native Tree Species to Soil Water Stress in a Tropical Forest on Limestone, Vietnam

Forests over limestone in the tropics have received little attention and limestone forests in Vietnam have been overlooked to an even greater extent in terms of tree physiology. In Ba Be National Park, Vietnam, soil water availability in limestone forests seems to be the most limiting factor in the dry season. Therefore, in order to enhance the preliminary knowledge of choosing native tree species for enrichment planting in the restoration zone, characteristics of the 20 native tree species to soil water stress were investigated in a limestone forest. One-ha plot each consisting of twenty-five 20 m × 20 m plots was established in undisturbed forests. All trees ≥ 10 cm DBH were measured in 20 m × 20 m plots, while twenty-five 5 m × 5 m subplots were established in order to sample the regeneration of tree species with a DBH w) and leaf osmotic potential (Ψπ) of the 20 native tree species, respectively in this study. 61 species belonging to 34 families of all trees with a DBH ≥ 10 cm were recorded in one ha, while 31 species representing 18 families of trees 2. The 20 species’ leaf water and osmotic potential values revealed significant differences among species. The maximum leaf water potential was not affected by any anticipated sources of variation, while the minimum water potential, however, showed significant variation to soil water stress. The results in the study area emphasized the importance of water factors in influencing tree species distribution; it could be concluded that native species with wide water potential ranges would be better able to withstand water changes and might be thus good candidates for reforestation (enrichment planting) in limestone areas.

Effect of Substrate Moisture Content and Invasive Grass Competition on Native Fig (Ficus fistulosa) Seedling Recruitment in Limestone Quarries

Challenges for restoration of degraded habitats on quarried limestone present in many countries including Indonesia. Ficus fistulosa as native species was chosen as a study species in the study of quarry restoration, as this species was shown in the previous study to have high importance value in Ciampea limestone forest in Bogor, West Java. To identify the effect of substrate moisture and competition from exotic Pennisetum grass to limestone restoration using native Ficus, we set up an experiment in the green house. Ficus above and belowground biomass were reduced because of the presence of Pennisetum grass and was affected by substrate moisture. Ficus biomass growth apparently was not favoured by higher irrigation. However, lower rate of irrigation led to the lower biomass of grass, meaning a lower competition from grass. On the other hand, it was apparent that the interaction of substrate moisture and presence of competition from grass reduced Ficus aboveground as well as belowground biomass. Furthermore, competition with grass was significantly reduced seedling’s leaf and length. Nevertheless, the interaction effect of substrate moisture and competition did not lead to the reduction of Ficus seedling’s leaf and length.  Â

Distribution and habitat of the Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 (Rodentia: Diatomyidae) in Vietnam.

The Laotian Rock Rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastes aenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L. aenigmamus in Vietnam is very small, approximately 150 km2, covering low karst mountains in five communes of Minh Hoa District, Quang Binh Province, at elevations between 250 and 400 m asl. The Laotian Rock Rat inhabits the lower part of steep karst towers with many rock boulders and crevices under tall limestone evergreen forest. They use small rock crevices for their dens. The natural habitat of this species in PNKB NP has been affected by selected timber harvesting, however, a complex 3-4 layer forest structure is retained. The Laotian Rock Rat is omnivorous, feeding on parts (leaves, buds, fruits and roots) of 18 plant species and also some insects (cicada, mantis, grasshopper). The population of this species in PNKB NP is seriously threatened with extinction due to its very restricted distribution, high hunting pressure, and habitat disturbance. Laonastes aenigmamus is listed in the IUCN Red List as endangered and in the Wildlife and Aquatic Red List of Lao, however, this species has not been listed in the Red Data Book or any conservation legislative documents of Vietnam.

Dietary adaptations of Assamese macaques (Macaca assamensis) in limestone forests in Southwest China.

Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat.

A new species of Cyrtodactylus (Squamata: Gekkonidae) from the karst forest of northern Laos.

We describe a new species of the gekkonid genus Cyrtodactylus on the basis of two specimens collected from limestone forests of Luang Prabang Province, northern Laos. Morphologically, the new species is distinguishable from its congeners by a combination of the following diagnostic characters: maximum SVL 86.1 mm; supralabials 9 or 10; infralabials 7-9; dorsal tubercles in 15 or 16 rows at midbody; ventral scale rows 34-36 at midbody; precloacal groove absent; femoral scales not distinctly enlarged; precloacal pores absent in females (unknown in males); subdigital lamellae under the fourth finger 18 or 19, under the fourth toe 18-20; subcaudals not transversally enlarged; dorsal bands white, 4 or 5 between limb insertions plus another one between hind limbs; tail banded. Based on molecular analyses, the new species is clustered in the same clade with C. wayakonei and two other species from Luang Prabang and Houaphan provinces.

A diminutive new species of cave-dwelling Wolf Snake (Colubridae: Lycodon Boie, 1826) from Peninsular Malaysia.

A newly discovered, diminutive, cave-dwelling, lowland species of the colubrid snake genus Lycodon Boie is described from a limestone cave along the Thai-Malaysian border in the state of Perlis, northwestern Peninsular Malaysia. Lycodon cavernicolus sp. nov. is most closely related to L. butleri Boulenger, an endemic, upland, forest-dwelling species from Peninsular Malaysia of the fasciatus group but is separated from L. butleri and all other species of the L. fasciatus group and the closely related L. ruhstrati group by having the combination of 245 (male) and 232 (female) ventral scales; 113 (male) and 92 (female) paired, subcaudal scales; a single precloacal plate; nine or 10 supralabials; 10 or 11 infralabials; a maximum total length of 508 mm (female); a relative tail length of 0.25-0.27; an immaculate venter in juveniles and dark-brown, posterior, ventral scale margins in adults; and dorsal and caudal bands in juveniles white. The discovery of L. cavernicolus sp. nov. adds to a rapidly growing list of newly discovered reptiles from karst regions and limestone forests of Peninsular Malaysia, underscoring the fact that these areas should be studied before they are quarried as they harbor a significant portion of the Peninsular Malaysia's herpetological diversity.

The Fate of Five Rare Tree Species after Logging in a Tropical Limestone Forest (Xuan Son National Park, northern Vietnam)

Rare tropical tree species are endangered due to the disappearance of old-growth forests. Although some undisturbed old-growth and formerly logged forests are protected today, the extent to which rare tree species persist and regenerate in such logged forests is often unclear. In a forested area over limestone in northern Vietnam, we studied the fate of five rare tree species after decades of logging and subsequent nine years of full protection, in comparison with an un-logged forest. Three of the studied species are largely restricted to limestone hills (Excentrodendron tonkinense, Chukrasia tabularis and Garcinia fagraeoides), while two of the species have a wider distribution (Parashorea chinensis and Melientha suavis). The bigger trees of the study species had lower densities and/or differences in the diameter distributions between the two forest types, indicating that these species had formerly been cut. The regeneration stem density of the study species was much lower (46% in M. suavis to 80% in P. chinensis) in the logged than un-logged forest. In the un-logged forest, we found clear relationships between ecological factors and regeneration density in four of the five study species; e.g., the regeneration of E. tonkinense increased with increasing rock-outcrop cover (r = 0.6, p < 0.01). Such relationships were almost absent in the logged forest. The widely distributed generalist species Cleidion javanicum dominated in the tree regeneration of the logged forest. Our results suggest that the studied rare tree species still existed as adults after logging and there was regeneration but at low densities. We assume that the potential for recovery remains, which further justifies the full protection of this and other restoration areas.

A new species of karst forest-adapted Bent-toed Gecko (genus Cyrtodactylus Gray, 1827) belonging to the C. sworderi complex from a threatened karst forest in Perak, Peninsular Malaysia.

A new species of Bent-toed Gecko Cyrtodactylus guakanthanensis sp. nov. of the C. sworderi complex is described from a limestone forest in Perak, Peninsular Malaysia whose karst formations at the type locality are within an active quarry. Cyrtodactylus guakanthanensis sp. nov. can be distinguished from all other Sundaland species by having the following suite of character states: adult SVL 77.7-82.2 mm; moderately sized, conical, weakly keeled, body tubercles; tubercles present on occiput, nape, and limbs, and extend posteriorly beyond base of tail; 37-44 ventral scales; no transversely enlarged, median, subcaudal scales; proximal subdigital lamellae transversely expanded; 19-21 subdigital lamellae on fourth toe; abrupt transition between posterior and ventral femoral scales; enlarged femoral scales; no femoral or precloacal pores; precloacal groove absent; wide, dark postorbital stripes from each eye extending posteriorly to the anterior margin of the shoulder region thence forming a transverse band across the anterior margin of the shoulder region; and body bearing five (rarely four) wide, bold, dark bands. Destruction of the karst microhabitat and surrounding limestone forest will extirpate this new species from the type locality and perhaps drive it to complete extinction given that it appears to be restricted to the particular microhabitat structure of the type locality and is not widely distributed throughout the karst formations. As with plants and invertebrates, limestone forests are proving to be significant areas of high herpetological endemism and should be afforded special conservation status rather than turned into cement.

Performance of Granitic, Shale, and Limestone Forest Road Aggregates Subjected to Repeated Loading

AbstractThis study compared the performance of three aggregate layers, commonly used in the construction of unbound forest roads in Ireland, when they were subjected to repeated loading in a new large-scale test rig. These layers comprised: (1) a layer of uncrushed, granitic, sandy gravel-a good quality road aggregate, (2) a layer of shale-a poor quality aggregate, and (3) a layer of crushed limestone–an excellent quality aggregate with a wet mix macadam (WMM) grading–on top of a poor quality shale subbase layer. The repeated load testing rig was designed and constructed to test different surface or completion layering thicknesses of the aggregates over a common formation or subgrade material of silty sandy soil. This testing was achieved by surface loading the aggregates through a 200-mm-diameter rubber pad-attached to a hydraulic actuator on the test rig-for up to 150,000 load applications. The subgrade pressures and surface deflections were measured at applied stresses of 500, 750, and 1,000 kPa. The g...

New country records of reptiles from Laos.

Four species of reptiles, of which one is represented by one of its subspecies, are recorded for the first time from Laos: Cyrtodactylus phongnhakebangensis, Lycodon futsingensis, and Lycodon ruhstrati, as Lycodon ruhstrati abditus, from limestone forests in Khammouane Province and Cyrtodactylus pseudoquadrivirgatus from hill evergreen forest in Salavan Province. These discoveries of lizards and snakes bring the total species number of reptiles to 189 in Laos.

Habitat association and conservation implications of endangered Francois' langur (Trachypithecus francoisi).

Francois’ langur (Trachypithecus francoisi) is an endangered primate and endemic to the limestone forests of the tropical and subtropical zone of northern Vietnam and South-west China with a population of about 2,000 individuals. Conservation efforts are hampered by limited knowledge of habitat preference in its main distribution area. We surveyed the distribution of Francois’ langur and modeled the relationship between the probability of use and habitat features in Mayanghe National Nature Reserve, Guizhou, China. The main objectives of this study were to provide quantitative information on habitat preference, estimating the availability of suitable habitat, and providing management guidelines for the effective conservation of this species. By comparing 92 used locations with habitat available in the reserve, we found that Francois’ langur was mainly distributed along valleys and proportionally, used bamboo forests and mixed conifer-broadleaf forests more than their availability, whereas they tended to avoid shrubby areas and coniferous forests. The langur tended to occur at sites with lower elevation, steeper slope, higher tree canopy density, and a close distance to roads and water. The habitat occupancy probability was best modeled by vegetation type, vegetation coverage, elevation, slope degree, distances to nearest water, paved road, and farmland edge. The suitable habitat in this reserve concentrated in valleys and accounted for about 25% of the total reserve area. Our results showed that Francois’ langur was not only restricted at the landscapes level at the regions with karst topography, limestone cliffs, and caves, but it also showed habitat preference at the local scale. Therefore, the protection and restoration of the langur preferred habitats such as mixed conifer-broadleaf forests are important and urgent for the conservation of this declining species.

Effects of foliage invertebrate availability and forest structure on the abundance of the critically endangered Rota White-eye Zosterops rotensis in Rota, Mariana Islands

SummaryThe Rota White-eye, Zosterops rotensis, is a critically endangered species endemic to the island of Rota, in the Mariana Islands, western Micronesia. There has been a dramatic decline in both its population size and range over the past few decades. The population, estimated at approximately 1,000 individuals in 1999, is found exclusively in 300 ha of mature limestone forest, though nearby areas of mature limestone forest remain unoccupied. We compared the bird community, vegetation characteristics and foliage-invertebrate density in forest plot pairs with known high and low densities of Rota White-eyes. Discriminant function analysis suggested that certain vegetation characteristics were best at predicting whether a plot was high-density or low-density. High-density plots had more stems with 20–50 cm DBH, more foliage intercepts at 3–9 m, more epiphytes, greater total canopy cover and fewer overall plant species. This information is essential for the protection of the current habitat of the Rota White-eye and for future efforts in the protection and management of this species.

Differences in the responses of photosystem I and photosystem II of three tree species Cleistanthus sumatranus, Celtis philippensis and Pistacia weinmannifolia exposed to a prolonged drought in a tropical limestone forest

Drought stress can induce closure of stomata, thus leading to photoinhibition. The effects of prolonged severe drought under natural growing conditions on photosystem I (PSI), photosystem II (PSII) and cyclic electron flow (CEF) in drought-tolerant tree species are unclear. In spring 2010, southwestern China confronted severe drought that lasted several months. Using three dominant evergreen species, Cleistanthus sumatranus (Miq.) Muell. Arg. (Euphorbiaceae), Celtis philippensis Bl. (Ulmaceae) and Pistacia weinmannifolia J. Poisson ex Franch. (Anacardiaceae) that are native to a tropical limestone forest, we investigated the influence of this stress on PSI and PSII activities as well as light energy distribution in the PSII and P700 redox state. By the end of the drought period, predawn leaf water potential (Ψ(pd)) largely declined in each species, especially in C. sumatranus. Photosystem I activity strongly decreased in the three species, especially in C. sumatranus which showed a decrease of 65%. The maximum quantum yield of PSII after dark adaptation remained stable in P. weinmannifolia and C. philippensis but significantly decreased in C. sumatranus. Light response curves indicated that both linear electron flow and non-photochemical quenching were severely inhibited in C. sumatranus along with disappearance of CEF, resulting in deleterious excess light energy in PSII. We conclude that PSI is more sensitive than PSII to prolonged severe drought in these three drought-tolerant species, and CEF is essential for photoprotection in them.

Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest

Biodiversity assessment of tropical taxa is hampered by their tremendous richness, which leads to large numbers of singletons and incomplete inventories in survey studies. Species estimators can be used for assessment of alpha diversity, but calculation of beta diversity is hampered by pseudo-turnover of species in undersampled plots. To assess the impact of unseen species, we investigated different methods, including an unbiased estimator of Shannon beta diversity that was compared to biased calculations. We studied alpha and beta diversity of a diverse ground ant assemblage from the Southeast Asian island of Borneo in different types of tropical forest: diperocarp forest, alluvial forest, limestone forest and heath forests. Forests varied in plant composition, geology, flooding regimes and other environmental parameters. We tested whether forest types differed in species composition and if species turnover was a function of the distance between plots at different spatial scales. As pseudo-turnover may bias beta diversity we hypothesized a large effect of unseen species reducing beta diversity. We sampled 206 ant species (25% singletons) from ten subfamilies and 55 genera. Diversity partitioning among the four forest types revealed that whereas alpha species richness and alpha Shannon diversity were significantly smaller than expected, beta-diversity for both measurements was significantly higher than expected by chance. This result was confirmed when we used the unbiased estimation of Shannon diversity: while alpha diversity was much higher, beta diversity differed only slightly from biased calculations. Beta diversity as measured with the Chao-Sørensen or Morisita-Horn Index correlated with distance between transects and between sample points, indicating a distance decay of similarity between communities. We conclude that habitat heterogeneity has a high influence on ant diversity and species turnover in tropical sites and that unseen species may have only little impact on calculation of Shannon beta diversity when sampling effort has been high.

Analysis and presevation of endemic plants in the Cockpit Country region of Jamaica

The Cockpit Country region of Jamaica is a dry limestone forest with extensive, Karst topography. It is characterized by numerous round-topped, conical hills and sinks. Much of the region has retained its natural vegetation with a high level of endemic species. The unusual landscape creates vastly different, isolated microhabitats which supports many unique organisms. Most of which have unexplored phytochemical and medicinal properties. The Natural Products Research Laboratory (NPRL) was recently established through grant funding from the Global Environmental Facility/Small Grants Programme/United Nations Development Fund (GEF-SGP-UNDP) and the Environmental Foundation of Jamaica (EFJ). The laboratory's objectives are: 1) to conduct basic pharmacological, biomedical and phytochemical investigations of endemic and endangered plants of the Cockpit Country; 2) to expose the human value of these species thereby promoting conservation; 3) to foster discovery and scientific interests among high school students through active engagement; 4) to train undergraduate and graduate students to the highest international levels within the field; and 5) to extend local and foreign collaborations for enhanced success. The NPRL is also creating a repository of endemic plant extracts for the further investigation and development. This presentation will highlight the novelty of the region while showcasing the diversity of species, ethnomedicine, and bioactivities.

A new Cyrtodactylus (Squamata: Gekkonidae) from Huong Son limestone forest, Hanoi, northern Vietnam

We describe a new species of the genus Cyrtodactylus based on two adult specimens from Huong Son limestone forest, Hanoi, Vietnam. Cyrtodactylus huongsonensis sp. nov. is distinguished from the remaining Indochinese bent-toed geckos by a combination of the following characters: medium-sized, with a maximum SVL of 89.8 mm; dorsal pattern consisting of dark nuchal loop, neck band and five in part irregular transverse body bands between limbs; two en-larged lateral chinshields in contact with first postmental pair; dorsal tubercles present on occiput, body, forearms, hind limbs and tail base; 14–16 irregularly running dorsal tubercle rows; ventrals in 41–48 longitudinal rows at midbody; lateral skin folds present, without interspersed tubercles; six precloacal pores plus in total 17 femoral pores in males, which are separated by 8–12 poreless scales; enlarged femoral scales and precloacal scales present; three postcloacal spurs in males; subcaudal scales transversely enlarged. This is the 24th species of Cyrtodactylus known from Vietnam.

Recognizing Inland Expansion of Latte Period Agriculture From Multi-Disciplinary Data on Tinian, Commonwealth of the Northern Mariana Islands

ABSTRACT Archaeological investigations at the West Tinian Airport in the Commonwealth of the Northern Mariana Islands have revealed evidence of inland forest clearing and associated occupation at approximately AD 1155, near the beginning of the prehistoric Latte Period. Radiocarbon dated charred Cocos nucifera nutshell from a shallow feature within a thin organic cultural horizon suggests short-term occupation of a low limestone bench above nearby clay loam soils. While direct evidence of cultivars was not encountered within the feature or on its ceramics, pollen in the soils from Cycas, Hibiscus, a non-Cocos palm family, and wetland sedge Pseudoschizaea suggest native limestone forest resources were being exploited. Clearing of this forest was suggested by the presence of macerated cellulose tissue, an unidentified starch granule, and multi-lobate fiber phytoliths on two polished basalt adzes, plus abundant charcoal in the pollen sample, one indicator of agriculture often cited in the Marianas. Three possible postholes perhaps from an insubstantial structure built on the clay loam nearby suggest this site represents a swidden field camp. The presence of quartzose hybrid sand temper in two ceramic sherds from the feature, and quartz-free volcanic sand temper in two other sherds, indicates early inland expansion of agriculture on Tinian occurred within an era of contact with Saipan and Guam, respectively.

Isolation and characterization of antimicrobial, anti-inflammatory and chemopreventive flavones from premna odorata blanco

Premna odorata Blanco (Verbenaceae) is a native tree of the Philippines where its leaves are used traditionally for vaginal irrigation and tuberculosis. It is one of the seven components of a commercialized Philippine herbal preparation called “Pito-Pito”. Its medicinal uses, however, have not been scientifically validated. This tree is not commonly cultivated and thrive in the less accessible limestone forests of the Philippines. Solvent partitioning and fractionation of the ethanolic crude extract of the leaves isolated two yellow amorphous powders. The identities of these compounds were determined by LC/MS/MS and NMR spectroscopic analyses, and their spectra were compared with literature data. The isolates were flavone aglycones which were the widespread acacetin and the non-widespread diosmetin. These flavones were isolated from the P. odorata for the first time ever. They had been reported by earlier studies to exhibit medicinal properties as antimicrobial, anti-inflammatory and chemopreventive. Thus, the current study has provided a scientific evidence of the medicinal properties of the leaves of P. odorata that could become the popular basis for the plant’s sustainable use, conservation and cultivation. Key words: Premna odorata Blanco (Verbenaceae), “pito-pito”, “alagau”, antimicrobial, anti-inflammatory, chemopreventive, flavones, diosmetin, acacetin.

Nest Site Selection and Consequences for Reproductive Success of the Endangered Mariana Crow (Corvus kubaryi)

Reasons for the decline of the Mariana Crow (Corvus kubaryi) on the Western Pacific island of Rota are currently unknown, but a need to protect nesting habitat has been suggested. We examined 55 actual nest sites and 60 random sites from 1997 to 1999 to investigate habitat characteristics specific to crow nest sites. Both nests and random plots were predominantly in limestone forest habitat. Discriminant function analyses indicate actual nest sites were differentiated from random sites based on a higher percentage of canopy cover and mean DBH of papaya (Carica papaya) and woody vines, as well as a higher stem count of species associated with limestone forests. This resulted in correct classification of a potential site as nesting versus random in 92% of the cases. Actual nests were .300 m from buildings, while random sites averaged (6 SE) 226.7 6 71.6 m from a building. Actual nest sites were about twice as far from a road as random nest sites. Twenty-eight of the 55 active nests fledged young. Nests in native forests were associated with higher reproductive success than nests in more disturbed areas. These findings suggest that damage to habitat from anthropogenic or natural causes may be limiting nesting success. Received 19 February 2010. Accepted 22 November 2010.

Landscape matrix and species traits mediate responses of Neotropical resident birds to forest fragmentation in Jamaica

Land cover and land use surrounding fragmented habitat can greatly impact species persistence by altering resource availability, edge effects, or the movement of individuals throughout a landscape. Despite the potential importance of the landscape matrix, ecologists still have limited understanding of the relative effects of different types of land cover and land uses on species patterns and processes in natural systems. Here we investigated whether Neotropical resident bird communities in limestone forest patches differed if they were embedded in three different human‐dominated matrix types (agriculture, peri‐urban development, and bauxite mining) relative to sites in continuous forest in central Jamaica. We found that species richness, community composition, and abundances were matrix‐dependent, with agricultural landscapes supporting greater avian diversity and more intact community assemblages than either peri‐urban or bauxite landscapes. Abundance of almost 70% of species differed in forest embedded in the different landscape matrix types. Traits related to resource use best predicted species responses, including diet guild, nest height, habitat association, and foraging strata. Insectivores, frugivores, canopy nesters, understory and canopy foragers, and forest‐restricted species rarely observed in matrix habitats had lower abundances in forest fragments embedded in human‐dominated matrix types than in continuous forest. In contrast, nectarivores, omnivores, granivores, ground and multi‐strata nesters, ground foragers, and species regularly in matrix habitats were least sensitive to forest fragmentation. Results suggest that structure, composition, and land use disturbance regimes in matrix areas impact overall habitat quality in landscapes by potentially mediating resource availability inside as well as outside forest habitat. This study reinforces the importance of differentiating among land cover and land uses in fragmentation research and lends support to the hypothesis that resource availability may be a primary factor driving Neotropical bird responses to fragmentation.