Clusia Hilariana Research Articles

PRECIPITATION DEFICITS AND HIGH TEMPERATURE INCREASE LEAF LITTERFALL IN OPEN RESTINGA VEGETATION, IN SOUTHERN BRAZIL

Climate is an important driver of litterfall along different ecosystems. However, little is known about how climate affects litter production in plant communities of Restinga. The aim of this study is to characterize the temporal variation in leaf litter production in an Open Clusia Formation in Restinga de Jurubatiba National Park, from 2001 to 2018, and assess how local variability in litter production reflects the local climatic conditions and its variability. We tested the hypothesis that monthly leaf litterfall increases in dry months and in drier and warmer than average months; we also evaluated if annual leaf litterfall increases in wetter and warmer years following leaf production patterns, that increases in these conditions. We found that litterfall peaks in the drier months. This pattern is consistent for many tropical ecosystems, even evergreen ecosystems, and may have evolved as a strategy that result in reduced water stress by plants, during drier and warmer periods, or may simply be a stress symptom. However, we also found that decreases in monthly rainfall and increases in monthly ∆Temperature (temperature observed minus estimated based on 1970-2000 interval) stimulate leaf litter production. Hot and warmer than average years also seem to stimulate leaf litterfall. It suggests that annual leaf litterfall and leaf production are less affected by precipitation regimes than variations in temperature (or radiation, which is directly related to temperature). It may result from the fact that Clusia hilariana, the dominant species in this ecosystem which accounts to 80 % of leaf litterfall, is a CAM photosynthesis species, a characteristic commonly associated with avoidance of water stress by plants. Although leaf litterfall seems to be predominantly driven by climate at annual scale, only 15 % of its variation was associated to climate at seasonal scale, suggesting that local factors control litterfall at lower temporal scales in Open Clusia Formation.

Effects of semi-purified fractions from stems of Clusia hilariana on the development of Dysdercus peruvianus

Plants represent a huge source of substances, with pharmacological potential. Brazil has a diversity of agricultural insect pests and an urgent need for safer methods of insect control. Dysdercus peruvianus (Guerin-Meneville, 1831), Pyrrhocoridae, is an economically important species of the Order Hemiptera and a pest of cotton (Gossypium hirsutum L., Malvaceae). Secondary metabolites in stems of Clusia hilariana Schltdl., Clusiaceae, such as terpenes and benzophenones, have been reported to be insecticidal. The present study investigated the effects of semi-purified fractions of hexane crude extracts from male C. hilariana stems on development of D. peruvianus. Biological parameters at different stages of development including body malformations, range of molting period and toxicity were evaluated. Most insects died and failed to develop due to attachment of their exuviae to the abdomen. Deformations of wings and defective tarsi also occurred. The secondary metabolites from semi-purified fractions of C. hilariana caused mortality, interference in molting and metamorphosis, and body deformations, probably by interacting with the neuroendocrine system. The results demonstrate the potential of C. hilariana extracts as an alternative for the control of the phytophagous insect D. peruvianus and for the development of environmentally safe and biodegradable bio insecticides.

Matter turnover in the oligotrophic restinga ecosystem and the importance of the key species Clusia hilariana

Abstract: Restingas are sandy areas spread along the Brazilian coast made up of a mosaic of forest and open woodland vegetation adapted to varying conditions of aridity, oligotrophy and salinity. Two vegetation types are very common in southeast Brazilian restingas, open Clusia formations and seasonally dry forest formation. Litter production and nutrient (C and N) turnover were studied comparatively in forest formations and Clusia formations, in vegetation patches with and without Clusia hilariana. The results showed that the breakdown process is extremely retarded in Clusia formations, with or without C. hilariana, leading to C accumulation in the soil. Microbial and soil fauna activity is lower in Clusia formations in comparison to forest formations; patches without Clusia hilariana showed intermediate conditions regarding total matter and carbon loss. Nitrogen loss was lowest in patches without C. hilariana, where soil micro-organisms accumulate N during the decomposition process, such as in the forest. The ratio of lignin in litter and the slow release of N reinforce the importance of the dominant tree Clusia hilariana as a potential key species for organic matter turnover. The accumulation of organic matter under the Clusia formation vegetation may be determinant for the humus richness of some bodies of water in the restinga, demonstrating the importance of this species to the ecosystem.

Long-term regeneration of a tropical plant community after sand mining.

Sandy coastal plant communities in tropical regions have been historically under strong anthropic pressure. In Brazil, these systems shelter communities with highly plastic plant species. However, the potential of these systems to regenerate without human assistance after disturbances has hardly been examined. We determined the natural regeneration of a coastal sandy plain vegetation (restinga) in Brazil, 16 years after the end of sand removal. We inventoried 38 plots: 20 within a sand‐mined site and 18 in an adjacent undisturbed site. We expected lower diversity values in the sand‐mined site compared to the undisturbed site, but similar species composition between the two sites due to the spatial proximity of the two sites and the high plasticity of restinga species. Species were ranked using abundance and importance value index in both sites, and comparisons were performed using Rényi entropy profiles, rarefaction curves, principal component analysis, and redundancy analysis. Species composition and dominant species differed markedly between the two sites. Bromeliads and Clusia hilariana, well‐known nurse plants, dominated the undisturbed site but were almost absent in the regenerating site. Species richness did not differ between both sites, but diversity was higher in the undisturbed site. Within‐site composition differences in the mined area were associated with field characteristics. Interestingly, species classified as subordinate or rare in the undisturbed site became dominants in the regenerating site. These newer dominants in the sand‐mined site are not those known as nurse plants in other restingas, thus yielding strong implications for restoration.

Clusia hilariana and Eugenia uniflora as bioindicators of atmospheric pollutants emitted by an iron pelletizing factory in Brazil.

The objectives of this work were to evaluate if the pollution emitted by the pelletizing factory causes visual symptoms and/or anatomical changes in exposed Eugenia uniflora and Clusia hilariana, in active biomonitoring, at different distances from a pelletizing factory. We characterize the symptomatology, anatomical, and histochemistry alterations induced in the two species. There was no difference in the symptomatology in relation to the different distances of the emitting source. The foliar symptoms found in C. hilariana were chlorosis, necrosis, and foliar abscission and, in E. uniflora, were observed necrosis punctuais, purple spots in the leaves, and increase in the emission of new leaves completely purplish. The two species presented formation of a cicatrization tissue. E. uniflora presented reduction in the thickness of leaf. In C. hilariana, it was visualized hyperplasia of the cells and the adaxial epidermis did not appear collapsed due to thick cuticle and cuticular flanges. Leaves of C. hilariana showed positive staining for iron, protein, starch, and phenolic compounds. E. uniflora showed positive staining for total phenolic compounds and starch. Micromorphologically, there was accumulation of particulate matter on the leaf surface, obstruction of the stomata, and scaling of the epicuticular wax in both species. It was concluded that the visual and anatomical symptoms were efficient in the diagnosis of the stress factor. C. hilariana and E. uniflora showed to be good bioindicators of the atmospheric pollutants emitted by the pelletizing factory.

Essential Oils from Male and Female Flowers of Clusia hilariana

Essential Oils from Male and Female Flowers of Clusia hilariana

Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae) caused by particulate deposition of iron

This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

Independent fluctuations of malate and citrate in the CAM species Clusia hilariana Schltdl. under low light and high light in relation to photoprotection

Clusia hilariana Schltdl. is described in literature as an obligate Crassulacean acid metabolism (CAM) species. In the present study we assessed the effect of irradiance with low light (LL, 200μmolm−2s−1) and high light (HL, 650–740μmolm−2s−1), on the interdependency of citrate and malate diurnal fluctuations. In plants grown at HL CAM-type oscillations of concentration of citrate and malate were obvious. However, at LL daily courses of both acids do not seem to indicate efficient utilization of these compounds as CO2 and NADPH sources. One week after transferring plants from LL to HL decarboxylation of malate was accelerated. Thus, in the CAM plant C. hilariana two independent rhythms of accumulation and decarboxylation of malate and citrate take place, which appear to be related to photosynthesis and respiration, respectively. Non photochemical quenching (NPQ) of photosystem II, especially well expressed during the evening hours was enhanced. Exposure to HL for 7 d activated oxidative stress protection mechanisms such as the interconversion of violaxanthin (V), antheraxanthin (A) and zeaxanthin (Z) (epoxydation/de-epoxydation) measured as epoxydation state (EPS). This was accompanied by a slight increase in the total amount of these pigments. However, all these changes were not observed in plants exposed to HL for only 2 d. Besides violaxanthin cycle components also lutein, which shows a small, but not significant increase, may be involved in dissipating excess light energy in C. hilariana.

Availability peak of caloric fruits coincides with energy-demanding seasons for resident and non-breeding birds in restinga, an ecosystem related to the Atlantic forest, Brazil

We evaluated temporal variation and quality of food resources available to birds especially in two energy-demanding seasons: one when there is a peak of molting residents and another when non-breeding individuals are the bulk of biomass of captured birds. Birds were captured and observed, as well as fruits counted and collected, in two restinga sites for 2 years. Molting resident birds may rely basically on the regularly produced Clusia hilariana and Erythroxylum spp. fruits as lipid-sources, while non-breeders count on Ocotea notata fruits (also rich in lipids) during their passage by the study site. We found that fruits with sugars, lipids or proteins were available throughout the whole period, but a more intense seasonal variation was observed for the before mentioned plant species. The birds studied are known to be potential seed dispersers of these plant species, which are important components of restinga plant community structure.

Germination biology and seedling growth of Clusia hilariana Schltdl., a dominant CAM‐tree of drought‐prone sandy coastal plains

AbstractThe spatial and temporal fluctuations of water availability can be an obstacle for recruitment of many species in the restinga and might restrict seed germination and seedling growth in specific regeneration safe‐sites. Clusiahilariana is one of the most dominant species of Restinga de Jurubatiba. This species has a high proportion of seedling establishment occurring inside the tanks of soil bromeliads underneath vegetation patches. Given the thin seed coats, the fast germination time and seed dispersal of C. hilariana during the dry season, we hypothesized that their major regeneration niche (the tanks of soil bromeliads) is related to susceptibility of seed germination and also seedling growth to low water availability. To test this hypothesis, seeds were germinated under decreasing water potentials using PEG 6000 solutions and seedlings were grown under varying water regimes. The percentage of seed germination progressively decreased at lower water potentials. After 38 days in −1.0 MPa no seeds germinated. However, approximately 90% of seeds germinated when transferred to Ψ = 0 MPa. The relative growth rates of seedlings of C. hilariana did not differ between water treatments. Thus, the major regeneration niche of C. hilariana is not a consequence of a high sensitivity of seeds and seedlings to water shortage. Nonetheless, C. hilariana showed an array of seed and seedling traits that may help to overcome establishment constraints of the harsh environment of restingas.

Galhas de insetos do Parque Estadual Paulo César Vinha (Guarapari, ES, Brasil)

Galhas de insetos do Parque Estadual Paulo César Vinha (Guarapari, ES, Brasil). Trinta e oito morfotipos de galhas de insetos foram encontradas em 21 espécies de planta (19 gêneros e 17 famílias) no Parque Estadual Paulo César Vinha (Guaparari, ES). A maioria das galhas ocorreu em folhas (84%). Galhas caulinares (13%) e das gemas (3%) também foram encontradas. Galhas uniloculares foram mais freqüentes (52%), assim como as glabras (89%). A maioria delas (84%) foi induzida por Cecidomyiidae (Diptera). Galhas de Hemiptera também foram encontradas (16%). Vespas parasitóides (Hymenoptera) foram obtidas de 22 morfotipos de galha, estando representadas por Eurytomidae, Eulophidae, Platygasteridae, Pteromalidae e Torymidae. Inquilinos foram encontrados em três morfotipos, estando representados por Coleoptera, Lepidoptera e Thysanoptera. Formigas predadoras (Formicidae, Hymenoptera) foram obtidas de um único morfotipo. Acarii e Psocoptera foram encontrados como sucessores em três morfotipos. Nyctaginaceae, Myrtaceae, Sapotaceae, Lauraceae e Smilaceae foram as famílias de planta com maior riqueza de galhas. Cinco novos registros de plantas hospedeiras são apresentados: Emmotum nitens (Icacinaceae), Andira nitida (Fabaceae), Chaetocarpus myrsinites (Euphorbiaceae), Salzmania nitida DC. (Rubiaceae) e Epidendrum denticulatum (Orchidaceae). Três novos registros de galhas de insetos em três espécies de planta - Clusia hilariana (Clusiaceae), Guapira pernambuscensis (Nyctaginaceae) e Ouratea cuspidata (Ochnaceae) são assinalados. Todos os registros apresentados são novos para o estado do Espírito Santo.

Photosynthetic changes and oxidative stress caused by iron ore dust deposition in the tropical CAM tree Clusia hilariana

The effect of iron solid particulate matter (SPMFe) deposited onto soil and leaves on photosynthesis and oxidative stress was evaluated in Clusia hilariana, a CAM tropical tree of high occurrence in Brazilian restingas. Significant increases in iron content were found in plants exposed to SPMFe applied onto leaf and soil surfaces. However, only the application of SPMFe on leaves of C. hilariana caused significant reductions in some evaluated characteristics such as photosynthetic rate, stomatal conductance, transpiration, organic acid accumulation, potential quantum yield of PSII, and changes in daily CAM photosynthesis pattern. Increase in relative membrane permeability and reduction in catalase and superoxide dismutase activities in the leaves of plants exposed to SPMFe also were observed; however, lipid peroxidation did not change. These responses seem to be due to the combination of physical effects such as increase of leaf temperature, reduction in light absorption, obstruction of stomatal pores, and biochemical effects triggered by oxidative stress.

Larvas de insetos associadas a Clusia hilariana Schltdl. (Clusiaceae) na Restinga de Jurubatiba, RJ, Brasil

Clusia hilariana é uma das espécies de plantas mais abundantes no Parque Nacional, desempenhando um papel importante na dinâmica sucessional desse ecossistema de restinga. Esse trabalho apresenta a composição e aspectos ecológicos das espécies de larvas de mariposas encontradas em C. hilariana. Em 40 plantas, mensalmente vistoriadas, foram obtidas quatorze espécies de lepidópteros. Chloropaschia granitalis foi a espécie de larva mais abundante alimentando-se nessa espécie de planta.

Comparison of the performance of three different ecophysiological life forms in a sandy coastal restinga ecosystem of SE-Brazil: a nodulated N2-fixing C3-shrub (Andira legalis (Vell.) Toledo), a CAM-shrub (Clusia hilariana Schltdl.) and a tap root C3-hemicryptophyte (Allagoptera arenaria (Gomes) O. Ktze.)

In a sandy coastal restinga ecosystem NE of Rio de Janeiro, Brazil, subject to environmental stress due to high irradiance, high temperature and low water supply, a comparative ecophysiological study of three species of different morphotypes and physiotypes was conducted during the dry season. The morphotypes were two shrubs, Clusia hilariana Schltdl. and Andira legalis (Vell.) Toledo, and the taproot hemicryptophyte Allagoptera arenaria (Gomes) O. Ktze. The physiotype differences were that C. hilariana was performing crassulacean acid metabolism (CAM), A. legalis was a nodulated N2 fixing legume and A. arenaria had ample access to water by ground water tapping roots. All three species were light stressed and showed photoinhibition and high maximum values of non-photochemical quenching of chlorophyll fluorescence. δ13C values of bulk leaf organic matter (which integrate over the life span of the leaf) and instantaneous gas exchange patterns demonstrated that C. hilariana was performing CAM and the other two species C3-photosynthesis. A. arenaria performed generous and A. legalis conserving use of water. Based on the CO2 concentrating mechanism of CAM C. hilariana had the highest maximum rates of apparent photosynthetic electron transport, ETRmax. Uptake of atmospheric CO2 in the afternoon (phase IV of CAM) was expressed weakly showing that the plants were under some but not severe water stress. A. legalis showed the highest levels of total N and soluble non-protein N-compounds in its organs due to N2 fixation which, however, did not confer a higher photosynthetic capacity that must have been limited by factors other than nitrogen supply. Accumulation of amino compounds like proline and γ-aminobutyric acid in leaves of A. legalis which are known to act as osmoprotectants is likely to indicate drought stress in the dry season. Maximum net CO2 uptake of photosynthesis was higher in the water spending A. arenaria than in A. legalis. The comparative analysis of physiological traits characterised either instantaneously or integrated over the longer term shows that in addition to morphotypic characteristics physiotypic characteristics are important for space occupation and niche acquisition of the plants in the restinga.

Spatio-temporal variation of photosynthetic pigments in the CAM tree Clusia hilariana Schlechtendal associated with dry spells during the rainy season in southeastern Brazil

In this work we assessed spatial and temporal variation of leaf pigment content of Clusia hilariana, a dominant CAM tree on the sandy coastal plains of SE Brazil. Chlorophyll a + b concentration, chlorophyll a/b ratio, and total carotenoid concentration were measured three times during the wet season. Chlorophyll a + b and total carotenoids decreased while the chlorophyll a/b ratio increased after a series of dry spells. We discuss our results in the context of Clusia literature, and argue that leaf-level pigmentation changes are an important source of phenotypic flexibility during acclimation to fluctuating light levels and groundwater availability.

Potential role of frugivorous birds (Passeriformes) on seed dispersal of six plant species a restinga habitat, southeastern Brazil

Restingas are considered stressful habitats associated with the Brazilian Atlantic forest, and their ecological interactions are poorly known. The goal of the present study was to determine the potential role of frugivorous birds as seed dispersers in a restinga habitat. Data were collected in Parque Nacional da Restinga de Jurubatiba, southeastern Brazil, where the main physiognomy (Open Clusia Formation) is characterized by the presence of patches of vegetation covering 20 to 48 % of the sandy soil and reaching a height of 5 m. Birds were captured with mist nets (12 x 2.5 m; 36 mm mesh; 1,680 net-hrs) and had their fecal and regurgitate samples inspected for seeds. Six plant species found in these bird samples were studied. The germination of seeds obtained from plants was compared to those from the birds. Both groups of seeds were set on Petri dishes at room temperature and washed when infected with fungi. In general, there was no effect on germination rate, and the effect on germination speed was negative. Germination of seeds from Pilosocereus arrabidae treated by the birds seemed to be influenced by storage of defecated seeds, while few Miconia cinnamomifolia seeds both from plants and from birds germinated. Ocotea notata presented a great variation in time to the onset of germination, perhaps an advantage against dissecation. Aechmea nudicaulis, Clusia hilariana and Erythroxylum subsessile probably take advantage of the arrival to favorable microhabitats, not by the gut effect on the seeds. All plant species studied are numerically important for the community and some of them are main actors in the succession of vegetation patches. Among the birds, Mimus gilvus is an important resident species, endemic to restingas in Brazil, while Turdus amaurochalinus is a visitor and may be important for plants that fructify during its passage by the study site. Although the effect of pulp removal was only tested for one species (Achmea nudicaulis) in the present study, we confirmed that the tested effect of restinga frugivorous birds on seed germination was generally null. Although there is a need for more detailed studies on specific animal-plant interactions on this habitat, the overall effect of the birds on seed dispersal in restinga is probably positive.

Low fruit set in the abundant dioecious tree Clusia hilariana (Clusiaceae) in a Brazilian restinga

Clusia hilariana (Clusiaceae), a dioecious tree, is an important nurse plant in the open, patchy restinga vegetation of coastal sandy plains in northern Rio de Janeiro (SE-Brazil). Although highly abundant locally, we found low production of fruit and viable seeds in open-pollinated as compared to hand-pollinated flowers. Reward from flowers of both sexes was resin, which was produced in higher quantities in male flowers. Flower visitors, including honeybees, were infrequent. We argue that low sexual reproductive success was due to inefficient pollen transport, and that vegetative propagation may contribute significantly to the high abundance of plants of this species.

Phosphoenolpyruvate carboxylase genes in C3, crassulacean acid metabolism (CAM) and C3/CAM intermediate species of the genus Clusia: rapid reversible C3/CAM switches are based on the C3 housekeeping gene

The genus Clusia includes species that exhibit either the C3 or crassulacean acid metabolism (CAM) mode of photosynthesis, or those that are able to switch between both modes according to water availability. In order to screen for species-specific genetic variability, we investigated the key carboxylase for CAM, phosphoenolpyruvate carboxylase (PEPC). Sequence analysis of DNA isolated from the obligate CAM species, Clusia hilariana, the obligate C3 species, Clusia multiflora, and an intermediate species that can switch between C3 and CAM photosynthesis, Clusia minor, revealed three different isoforms for C. hilariana and one each for the other two species. Sequence alignments indicated that PEPC from the intermediate species had high homology with the C3 protein and with one of CAM plant proteins. These were assumed to constitute 'housekeeping' proteins, which can also support CAM in intermediate species. The other two isoforms of the CAM plant C. hilariana were either CAM-specific or showed homologies with PEPC from roots. Phylogenetic trees derived from neighbour-joining analysis of amino acid sequences from 13 different Clusia species resulted in two distinct groups of plants with either 'housekeeping' PEPC only, or additionally CAM-related isoforms. Only C. hilariana showed the third, probably root-specific isoform. The high homology of the PEPC from the intermediate species with the C3 protein indicates that for the reversible transition from the C3 to CAM mode of photosynthesis, the C3 type of PEPC is sufficient. Its expression, however, is strongly increased under CAM-inducing conditions. The use of the C3 isoform could have facilitated the evolution of CAM within the genus, which occurred independently for several times.

Aboveground biomass stock of native woodland on a Brazilian sandy coastal plain: Estimates based on the dominant tree species

The restingas of coastal Brazil are vegetation mosaics that include forests and open woodlands. One of the most common restinga vegetation types in Rio de Janeiro state, an open woodland, is dominated by the crassulacean acid metabolism (CAM) tree Clusia hilariana Schltdl. (Clusiaceae). We provide allometric equations and biomass estimation for this species on three sites varying woody plant cover. Estimated aboveground biomass stock of C. hilariana plus the litter accumulated underneath the canopy of these plants ranged from 0.64 to 8.63 t ha −1 depending on plant cover. These values are often comparable to those of the entire woody component of many neotropical savannas, which have been claimed to have important impact on global carbon cycles. The litter-layer represents 31% of aboveground biomass, which is very high when compared to other tropical savannas. This indicates that slow decomposition may play an important role on carbon accumulation at the studied ecosystem. Thus, C. hilariana, despite its conservative strategy of carbon acquisition via CAM, gives a high contribution to biomass stock in this nutrient-poor coastal vegetation in the tropics.

Habitat use by Oryzomys subflavus (Rodentia) in an open shrubland formation in Restinga de Jurubatiba National Park, RJ, Brazil

The Restinga de Jurubatiba has at least 10 plant formations, including open Clusia shrubland. This formation is composed of dense shrubs of many shapes and sizes, where Clusia hilariana is one of the most important plant species. Shrublands with Clusia (CC) are poorer in plant species and less dense than shrublands without Clusia (SC). Oryzomys subflavus (Rodentia) is the most abundant small mammal species in the open Clusia shrubland. We tested the hypothesis that the abundance of rodents would increase with the size of the patch and would be higher in SC shrublands. Rodents were captured, marked and released in three 780-m-long transects. At each capture site, we evaluated the shape of the shrubland patch, calculated the area and noted the category of the shrubland. Using ANCOVA, we ascertained whether the abundance of Oryzomys subflavus increased with the sampled area and used CC and SC shrublands differently. We also verified if the size of patches used by rodents varies in the same frequency as the size of available shrublands. Rodent abundance was found to increase significantly with the area. There were no differences in the size of the patches used by rodents and the frequency of the size of available patches. This finding indicates that O. subflavus, in the study area, is a generalist species that uses its habitat according to availability.