Analysis Of Vegetation Structure Research Articles

Deforestation detection from spaceborne full-waveform laser altimetry, incorporating terrain effects: A case study in Porto Velho, Brazil

Forest structure, notably the canopy height above the ground, can be obtained from the full-waveform data acquired by satellite laser altimetry. On sloped terrain, the laser pulse can simultaneously reflect from both the vegetation and the ground within their intersecting vertical extents, causing their signals to overlap. This overlap complicates the separation of canopy and ground in the analysis. Consequently, accurately obtaining canopy height and its variation, while considering the influence of terrain factors, poses a significant challenge.In this paper, to counter this, we introduce an innovative approach to remove terrain effects for more reliable identification of canopy and ground. Overlapping footprints from the Ice, Cloud, and land Elevation Satellite (ICESat)/Geoscience Laser Altimeter System (GLAS) and Global Ecosystem Dynamics Investigation (GEDI) campaigns are extracted as coincidental observations. Utilizing the different footprint sizes and by minimizing the center and width of each decomposed Gaussian component pair, optimized ground returns can be obtained. Validation using airborne LiDAR data from the Bartlett Experimental Forest, New Hampshire, USA, indicate that the proposed approach can reduce the ground elevation root-mean-square error (RMSE) by approximately 3 m, compared to the prevalent methods and standard products. While the GEDI product algorithms exhibit a certain accuracy in canopy height retrieval, the proposed approach presents a more constrained error band, signifying less impact from ground elevation discrepancies.While the proposed method enhances canopy height precision, its reliance on overlapping footprints means sacrificing some observations. However, the proposed method is effective in scenarios such as change detection that require repeat observations. As a case study, we applied the proposed method in Porto Velho, Rondônia, Brazil, which is a deforestation hotspot. Using the GlobeLand30 dataset, we investigated the land-cover dynamics from co-located laser footprints, identifying significant forest loss areas and validating our findings with the Hansen Global Forest Change dataset, achieving an accuracy of 83.81 %.In conclusion, this research emphasizes the significance of terrain topography effects in vegetation structure analysis, and positions satellite laser altimetry as instrumental for forest monitoring.

Paleoclimatic Reconstruction Based on the Late Pleistocene San Josecito Cave Stratum 720 Fauna Using Fossil Mammals, Reptiles, and Birds

Advances in technology have equipped paleobiologists with new analytical tools to assess the fossil record. The functional traits of vertebrates have been used to infer paleoenvironmental conditions. In Quaternary deposits, birds are the second-most-studied group after mammals. They are considered a poor paleoambiental proxy because their high vagility and phenotypic plasticity allow them to respond more effectively to climate change. Investigating multiple groups is important, but it is not often attempted. Biogeographical and climatic niche information concerning small mammals, reptiles, and birds have been used to infer the paleoclimatic conditions present during the Late Pleistocene at San Josecito Cave (~28,000 14C years BP), Mexico. Warmer and dryer conditions are inferred with respect to the present. The use of all of the groups of small vertebrates is recommended because they represent an assemblage of species that have gone through a series of environmental filters in the past. Individually, different vertebrate groups provide different paleoclimatic information. Birds are a good proxy for inferring paleoprecipitation but not paleotemperature. Together, reptiles and small mammals are a good proxy for inferring paleoprecipitation and paleotemperature, but reptiles alone are a bad proxy, and mammals alone are a good proxy for inferring paleotemperature and precipitation. The current paleoclimatic results coupled with those of a previous vegetation structure analysis indicate the presence of non-analog paleoenvironmental conditions during the Late Pleistocene in the San Josecito Cave area. This situation would explain the presence of a disharmonious fauna and the extinction of several taxa when these conditions later disappeared and do not reappear again.

Floristic Composition, Structure, and Regeneration Status of Woody Plants in Wonjeta St Micheal Church Forest, Northwestern Ethiopia.

The study was conducted in a historian Wonjeta St Michael Church Forest, believed to be constructed in 11th century in Northwestern Ethiopia. The composition, structure, and management of this forest is not documented. Fifty plots of 20 m × 20 m (400 m2) were laid along five-line transect for vegetation data collection. In addition, 5 m × 5 m subplots were laid within the main plot to sample seedlings and saplings. All plots were laid at a distance of 50 m along the transect lines. The diversity and population structure of woody individuals of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm and height ≥2 m were measured, and DBH <2.5 cm and height <2 m were counted as seedlings and saplings. All trees and shrubs recorded in the 50 plots were used for vegetation structure analysis. A total of 65 woody plant species in 53 genera and 33 families were recorded. Out of the total number of species, three were found to be endemic to Ethiopia. The family Fabaceae had the highest number of species, followed by Moraceae, and then Euphorbiaceae with 14, 6, and 4 species, respectively. The results of Shannon Wiener diversity and evenness indices of woody species were 2.8 and 0.68, respectively. Woody species densities for mature individuals were 2,202.5 stems ha-1, seedling 2419.2 stems ha-1, and sapling 1737.6 stems ha-1. Priority for conservation should be given using population structure, important value index, and regeneration status as criteria. Results of the structural analysis revealed that the Forest is highly dominated by small-sized trees and shrubs indicating that it is in the stage of secondary development and there are species that require urgent conservation measures.

Analysis of vegetation structure of urban parks and environmental discomfort index in The City of Mataram

The high population growth in Mataram City with the consequence of increasing development has caused a decrease in the area of ​​green open land. Garden parks as part of green open land need to be maintained and evaluated for their vegetation to be able to control the impact of local climate change. This study aims to analyze the vegetation structure of garden parks in Mataram City and assess its ability to reduce the increase in the environmental discomfort index. Vegetation analysis was carried out in six garden parks in Mataram City using the transect-squared method. The observed vegetation variable was the lushness of each vegetation life form. Vegetation data was analysed to produce groups of urban park vegetation structures in Mataram City. Microclimate factors inside and outside the park, which include air temperature and humidity observed on a sunny day according to a two-way line interval design with a direction according to the shape and area of ​​the observed urban park. The data of air temperature and humidity were processed to produce an index of environmental discomfort. The results showed that the six urban parks observed in The City of Mataram were divided into three groups of vegetation structures, namely the form of trees &amp; shrubs (Ampenan Old Town Park, Udayana Garden and Selagalas park), forms of shrubs &amp; trees (Sangkareang Park and Garden of Mayura ) and forms of bushes &amp; shrubs (Malomba Park). The existence of city parks with variations in their vegetation structure in Mataram City does not cause variations in their ability to reduce the discomfort index. All city parks observed in Mataram City have moderate ability in reducing environmental discomfort index. Most of the areas outside the city parks in Mataram City have a class c of discomfort index and only Mayura Park, Malomba Park and Selagalas Park are known to reduce the discomfort class, namely from class c (discomfort felt by &gt;50% of the population) outside the park to class b (discomfort felt by &lt;50% of population) in the park.

Population Structure and Regeneration Status of Woody Species in Kenech Forest, Southwest Ethiopia

Understanding the structural pattern and regeneration status of tree species is an important measure taken to assess the vegetation dynamics and their destruction factors species as well as management history and ecology of the forest. This study was conducted with the objective to assess the species diversity, structure, and regeneration status of woody species in Kenech natural forest, Ethiopia. Systematic random sampling method was employed as a sampling design for the collection of vegetation data. Accordingly, 40 plots of 20 m × 20 m were laid at every 100 m along four parallel transect lines following altitudinal gradient. Any woody species of trees and shrubs with the diameter at breast height (DBH) ≥2.5 cm was measured at 1.5 m from the ground. In each sample plots, all woody species seedling, sapling, and mature woody species were counted and recorded. A total of 80 plant species categorized into 67 genera and 28 families were recorded and identified, for description and analysis of vegetation structure. Structural analysis of the Kenech natural forest revealed a density of 840 stems/ha and a total basal area of 56.8 m2/ha. About 80.36% of the individuals are found in the first two classes (2.5–10 and 10–20 cm). The general pattern of DBH class distribution of woody species in the study area revealed an inverted J shape indicating the presence of a high density of trees in the lower DBH class than in the higher. The most dominant tree species relatively with the highest importance values recorded in the area were Pouteria adolfi-friedericii, Podocarpus falcatus, Celtis africana, Mimusops kummel, Pyschotria orophila, and Olea capensis subsp. macrocarpa. Forty-two species (64.61%) were represented by both seedling and sapling class, whereas 9 species (13.84%) were not regenerating.

Analysis of Vegetation Structure on the 2&lt;sup&gt;nd&lt;/sup&gt; Old Trail in Mudeungsan National Park

Analysis of Vegetation Structure on the 2&lt;sup&gt;nd&lt;/sup&gt; Old Trail in Mudeungsan National Park

Quantitative analysis of vegetation structure, composition and species diversity of moist Sal bearing tropical forest of Sumbuk reserve forest in South Sikkim, India

Quantitative analysis of vegetation structure, composition and species diversity of moist Sal bearing tropical forest of Sumbuk reserve forest in South Sikkim, India

English

Wabero forest is one of the very few remnant moist evergreen montane forests in Southeast Ethiopia. However, basic data on vegetation structure and composition of the forest that could provide valuable information for possible conservation measures is lacking. The main objective of this study, therefore, was to investigate the woody species composition, vegetation structure and regeneration status of the forest. In the study 30 quadrants of 20 m by 20 m were used for woody species data and 5 m by 5 m for sapling and seedling in a nested form. The sample quadrants were laid down along transects at a distance of 300 m from each other. Diameters at breast height (DBH), basal area, frequency and importance value index were used for analysis of vegetation structure. In the study, a total of 47 woody plant species belonging to 43 genera and 33 families were recorded. The major families were Rubiaceae and Rutaceae each represented by four species followed by Sapindaceae, Moraceae and Oleaceae each represented by three species. The rest of the 28 families were represented by one or two species, only. The mean density of all the woody species recorded in the study site was 21,737 ha-1. Diospyros abyssinica, Podocarpus falcatus, Strychnos mitis, Celtis africana and Coffea arabica were found to be the most dominant and frequent species with the highest importance value index. Results of regeneration status of the forest, which was analyzed by comparing number of seedling and sapling with mature trees, revealed that the forest is under good regeneration status. Therefore, based on the results of the study, awareness creation and implementation of participatory forest management strategy is recommended in order to sustain the forest. &nbsp; Key words: Basal area, diameters at breast height (DBH), importance value index, Montane forest, woody species composition.

Structure of Riparian Vegetation and Its Implications for The Habitat Conditions of Arfak Rainbowfish, Melanotaenia Arfakensis at The Nimbai Stream, Manokwari, West Papua

Riparian vegetation has an important role in maintaining water stability, one of which is the river. This study aims to describe the structure of riparian vegetation so that its implications can be seen for the conditions of rainbow arfak habitat on the Nimbai River. The study was conducted in three forest types, namely primary riparia forest, secondary riparia forest and open riparia forest. Sample collection of riparian vegetation was carried out by purposive sampling using sample plots. Plots measuring 2 m x 2 m are used to sample seedling and understorey growth, plots measuring 5 m x 5 m for growth at the stake level, while plots measuring 10 m x 10 m and 20 m x 20 m, for growth of pole and tree levels respectively. The identification results obtained a total of 35 species of understorey and 51 tree-level plants in all three types of riparian forests. Based on the analysis of vegetation structure, it is known that the condition of primary riparia forest and secondary riparian forest still relatively supports the life of arfak rainbow fish compared to open riparian forest. Higher tree level density associated with canopy cover which has implications for the temperature of the water to be colder and less fluctuating, input larger litter into the food chain in the river, and hold suspended particles into the river. Also, the function of riparian vegetation in spawning activities, substrate attaching eggs and nursery habitat for arfak rainbow fish larvae. The results of this study indicate the importance of riparian vegetation structure on the condition of rainbow arfak fish habitat. An understanding of the structure of vegetation is also a basic information for efforts to rehabilitate this endemic fish habitat to maintain the existence of a natural population.

Overstory-understory land cover mapping at the watershed scale: accuracy enhancement by multitemporal remote sensing analysis and LiDAR.

In forested watersheds, density, land cover, and its vertical structure are crucial factors for flood management, ecosystem monitoring, and biomass inventory. Nowadays, producing land cover maps with high accuracy has become a reality with the application of remote sensing techniques, but in some situations, it is not so easy to distinguish between the overstory and understory vegetation with only spectral information. The main goal of this study was to analyze the accuracy enhancement in overstory and understory land cover mapping at the watershed scale when using the data fusion of seasonal and annual time series of Sentinel-2 images complemented with low-density LiDAR and soil and vegetation indices. The study area was composed by two neighboring watersheds in Badajoz province (Spain). The accuracy of land cover classifications was trained in two ways: first, for each season and several soil-vegetation indices; and second, for the annual series and soil-vegetation indices. Next, LiDAR data were included in both analyses by means of a Boolean metric concerning the height. The obtained results showed that the overall accuracy was better with the annual evaluation when only spectral information was used for the classification. Additionally, if LiDAR data were included in the classification (data fusion), the overall accuracies were highly improved, especially in summer and autumn seasons. This improvement can be a significant issue in the analysis of vegetation structure and its spatial distribution as it is decisive for watershed ecosystem management.

Vegetation structure influences the retention of airfall tephra in a sub-Arctic landscape

Vegetation cover mediates a number of important geomorphological processes. However, the effect of different vegetation types on the retention of fine aeolian sediment is poorly understood. We investigated this phenomenon, using the retention of fine, pyroclastic material (tephra) from the 2011 eruption of the Grímsvötn volcano, Iceland, as a case study. We set out to quantify structural variation in different vegetation types and to relate structural metrics to the thickness of recently deposited volcanic ash layers in the sedimentary section. We utilised a combination of vegetation and soil surveys, along with photogrammetric analysis of vegetation structure. We found that indices of plant community composition were a poor proxy for vegetation structure and were largely unrelated to tephra thickness. However, structural metrics, derived from photogrammetric analysis, were clearly related to variations in tephra layer thickness at a landscape scale and tephra layers under shrub patches were significantly thicker than those outside the shrub canopy. We therefore concluded that: a) vegetation cover was a critical factor in the retention of fine aeolian sediment for deposit depths up to few centimetres; b) structural variation in vegetation cover played a major role in determining the configuration of tephra deposits in the sedimentary section. These findings have implications for the analysis of ancient volcanic eruptions and archaeological/palaeoenvironmental reconstructions based on the interpretation of tephra deposits. Furthermore, they present the possibility that the detailed form of tephra layers may be used as a proxy for palaeo vegetation structure.

THE RECOVERY OF A DEGRADED MANGROVE IN CEARÁ THROUGH THE PRODUCTION OF Laguncularia racemosa (L.) C.F. Gaertn. (Combretaceae) AND Avicennia sp. Stapf ex Ridl (Acanthaceae) SEEDLINGS

ABSTRACT The mangrove ecosystem performs several natural functions of great ecological and economic importance. This study provided procedures for the recovery of mangrove ecosystems through the characterization of vegetation and zonation patterns and evaluation of growth and survival rates of mangrove species in an experimental plantation. The study was performed in the Acaraú River estuary mangrove on the western coast of Ceará State. The characterization of vegetation was conducted with the use of multiple plots and transects replication. Plants were identified at the species level, and their heights and CBH (circumference at breast height) were measured in each plot. Seedlings of the dominant mangrove species were produced using estuarine propagules. Five mangrove species were sampled: Rhizophora mangle, Avicennia germinans, Avicennia schaueriana, Laguncularia racemosa, and Conocarpus erectus. L. racemosa was the most dominant and frequent species, followed by A. germinas. A total of 111 L. racemosa and 102 Avicennia sp seedlings of were produced. Seedlings were viable for replanting within two months. The results of the analysis of vegetation structure and production and growth of seedlings are encouraging and demonstrate that revegetation is not only possible but also successful in this significantly deforested and degraded mangrove.

Object Oriented Image Analysis in Remote Sensing of Forest and Vineyard Areas

The study of vegetation cover, forests, orchards or vineyards and crops through satellite techniques is increasingly promoted as a result of facilities they offer. A number of methods and techniques for processing and analysis of satellite images are developed to increase the precision of the working, given the diversity of vegetation structure analysis and expected results. This study aimed to analyze the capabilities of object-oriented image analysis (OBIA) for recognition forest and vineyard areas. OBIA is automated process of object extraction by modelling of human visual system for image interpretation. The basis for classification process is object, which is created according to the set of characteristics. In object-oriented approach classification description is based on classification rules including spectral characteristics, size, shape, as well as content and texture information. Analysis is done on multispectral imagery of high and very high spatial resolution. Represented results show the usefulness of RapidEye and WorldView2 images as well as importance of classification based on OBIA. Object-oriented image analysis (OBIA) method based on satellite imagery has facilitated the recognition forest and vineyard areas with high accuracy.

Vegetation Properties of Daphniphyllum macropodum Natural Habitats in South Korea

To investigate the vegetation properties of Daphniphyllum macropodum natural habitats, a total of 21 plots(100m 2 ) were installed in 7 natural habitats with random sampling method and investigated their vegetation and soil characteristics. From the vegetation structure analysis, 8groups of D. macropodum-Carpinus laxiflora(Ⅰ), Neolitsea aciculata-D. macropodum(Ⅱ), D. macropodum-C. tschonoskii(Ⅲ), D. macropodum-Pinus densiflora(Ⅳ), D. macropodumDendropanax morbifera(Ⅴ), P. thunbergii(Ⅵ), Neolitsea aciculata(Ⅶ), C. laxiflora(Ⅷ) were classified by cluster analysis. D. macropodum was the dominant species in the upper and middle layer in the natural habitats of D. macropodum. High positive correlation showed between D. macropodum; Acer palmatum and C. laxiflora. Species diversity(H') of the investigated groups were in the range between 0.7308~0.9849. The soil pH and organic matter content of D. macropodum natural habitats were 3.7~5.0 and 3.7~14.7, respectively. Ulleungdo was slightly higher in the exchangeable cations compared to those of the other natural habitats. This study could be used as basic data to establish conservation and management plan of habitats on D. macropodum.

Studies of Vegetation Structure Analysis and Vegetation Transition over 25 years of Evergreen Broad-leaved Forest in Hong-Do Island

This study aims at classifying and interpreting on the vegetation structure and the vegetation transition over 25 years (between 1986 and 2010), and the correlation with the change of some conditions (the vegetation height and coverage on each layer and the climate factors as WI, CI, mean annual temperature, mean annual total precipitation etc.) in the Evergreen Broad-Leaved Forest,, Hong-Do island. The EBLF is classified into five units of vegetation (Hedera rhombea-Machilus thunbergii community (M-M comm.), Castanopsis sieboldii forest (Machilus japonica-Castanopsis sieboldii community; Raphiolepis indica var. umbellata-C. sieboldii community), community (Qa comm.), Carpinus turczaninovii community (Ct comm.), Camellia japonica stand (Cj stand)). The vegetation transition by CCA had high correlation with the height and coverage on each layer and the climate factors, and it did the succession (transition) that the M-M comm. (2010) from Mallotus japonicus community･Machilus thunbergii community･Carpinus coreana community (Cc comm.)･Aucuba japonica community (Aj comm.)･Trachelos permum asiaticum var. intermedium-Quercus acuta community (TQ comm.) (1986), the communities of C. sieboldii forest (2010) from Aj comm.･TQ comm.･Raphiolepis umbellata-Camellia japonica community (RC comm.) (1986), the Qa comm. (2010) from Ardisia japonica-Castanopsis sieboldii community (AC comm.) and TQ comm. (1986), the Ct comm. (2010) from Cc comm.･RC comm.･Aj comm.･Quercus serrata community and the Cj stand (2010) from AC comm. (1986). the height and coverage on each layer are also changed.

Analysis of Vegetation Structure Causing Top-Dying In Mangrove Forest Trees in the Sundarbans in Bangladesh

Sundarbans is the largest, biologically richest, and most extensive mangrove forest in the world (Christensen, 1984; Seidensticker and Hai, 1983; Hussain and Karim, 1994). Heritiera fomes (Sundri) is the predominant tree species, supporting about 65% of the total merchantable timber (Chaffey et al., 1985, and Siddiqi, 2001). A unknown and serious-killer disease (top dying) of H. fomes in Sundarbans is affecting millions of the trees. An inventory by Chaffey et al., (1985) revealed that there were about 45.2 million top dying trees in the Sundarbans of which 20 million had more than 50% of their crown affected by top dying. The loss of H. fomes will have a major impact on the Sundarbans mangrove ecosystem, which leads to economic losses. The vegetation structure was assessed in terms of tree height, bole diameter, species present, and regeneration status; and the intensity of top-dying within the plots was recorded on a rank scale. Most of the elements studied had no significant correlation with the top dying of Heritiera fomes. Of the hypotheses previously put forward to explain top-dying, the present results do not support enhanced salinity as the cause. It is likely that several of the above-mentioned environmental factors interact with each other to induce top dying in Sundri. However, the present results have showed that Sn, Exchangeable K, soil pH, Pb , Zn and Ni could be directly linked with top-dying of Heritiera fomes (Sundri) in Sundarbans, probably particularly by weakening the vigour of the trees and allowing other factors such as pathological agents to attack the plants.

PHYTODIVERSITY AND SOIL STUDY OF SHIWALIK HILLS OF ILAM, NEPAL: AN ECOLOGICAL PERSPECTIVE

The Siwalik range (locally known as Churia hills) in Nepal comprise a total area of 1,886,000 ha, equivalent to 13% of the country’s total area and consists of hills, steep land slopes, gorges, large spans of river and temporary streams. Study of different kinds of plants, soil and climate and the quantitative analysis of vegetation structure and composition as well as soil analysis at three Village Development Committees (VDCs) of Siwalik hills of Ilam was undertaken. A total number of 137 flowering plants and 8 pteridophytes are reported in the present study. Shorea robusta, Terminalia alata and Semecarpus anacardium are the most dominant species of the entire study area. The Siwalik range with late tertiary exposed rocks consists of fine grained sandstone with pockets of clay, shale, conglomerate and freshwater limestone. The vegetation is much more diverse and intact ecologically than expected from a distant observation. DOI: http://dx.doi.org/10.3126/eco.v18i0.9414Ecoprint: An International Journal of EcologyVol. 18, 2011 Page: Uploaded date: 12/22/2013

기후변화에 따른 가거도 상록활엽수림의 식생 구조, 종 다양성, 생활형의 변화 예측

This study aims at classifying and interpreting on the vegetation structure, the correlation between a vegetation and an environment, a species diversity and a life-form of Evergreen Broad-Leaved Forest(EBLF) located in Gageo-do Island. It is also the objective that the estimation of vegetation change founded on the species composition and characteristics. The vegetation of EBLF was classified into three forests or four community units as Machilus thunbergii forest (Polystichum polyblepharon-M. thunbergii community and Phaenosperma globosum-M. thunbergii community), Ilex integra-Castanopsis sieboldii community, Quercus acuta community and Neolitsea sericea stand. The ordination analysis by DCA is analogous with the vegetation structure analysis. As a result of the correlation (Pearson's correlation coefficient) with environmental conditions, the Altitude has the significance with the distribution of communities. The total vegetation change by progress of succession will not be wandered away from the present vegetation structure practically, and the vegetation on the underlayers will be a little changed.

Population structure of woody plants in the arid cloud forests of Dhofar, southern Oman

Abstract This study evaluates the size frequency distribution of 11 trees and shrubs in the cloud forest in Wadi Garziz, southern Oman, in order to assess their current situation, which is affected by cutting, overgrazing and other constraints. A size class distribution and a vegetation structure analysis were applied in order to analyze the dynamics of this forest using census data from 51 plots selected across 5 transects covering the hill-slope andwadi-bed habitats. Some of the trees inhabiting the hill-slopes (e.g. Acacia senegal and Commiphora spp.) were found to exhibit an inverse J-shaped distribution with constant regeneration, whilst in the wadi bed these same trees exhibited a J-shaped distribution (i.e. of declining populations). On the other hand, Acacia etbaica inhabiting the hill-slopes exhibited a tendency towards a J-shaped distribution and an inverse J-shaped distribution in the wadi-bed. All the populations (i.e. inhabiting the hill-slopes and the beds) of Anogeissus dhofarica had a J-shaped distribution whereas all the populations of Blepharispermum hirtum had a more or less inverse J-shaped distribution. The Ziziphus spina- -christi and Acacia tortilis populations, meanwhile, exhibited the bi-modal shape of size distribution. The shrubs inhabiting the hill-slopes (e.g. Coroton confertus and Ormocarpum dhofarense) exhibited a tendency towards a J-shaped distribution; such distribution characterizes a declining population with a limited regenerational capacity. Overall, most of the examined populations, except those of Acacia etbaica in wadi-bed and Blepharispermum hirtum, seemed to be under stress from both environmental and human factors, particularly in the wadi bed. This type of study can provide a basis for the development of a management plan to support the conservation and sustainable use of forest vegetation in an arid region.

Food availability in exotic grasslands: a potential mechanism for depauperate breeding assemblages

Abstract We investigated the influence of Old World bluestem (Bothriochloa ischaemum; OWB) monocultures on grassland bird abundance through analysis of vegetation structure and food availability. We compared breeding bird density, vegetation structure and composition, and arthropod biomass between six native grass and six OWB fields in the southern Great Plains. The OWB fields supported 1.70 ± 0.27 (mean ± SE) Grasshopper Sparrows (Ammodramus savannarum) per ha compared to 0.95 ± 0.25 in native grass fields, but total species richness was greater in native grass fields (40 versus 28 species). Density of some bird species was correlated with vegetation structure regardless of field type, suggesting that management practices may be more influential than plant species composition. Mean arthropod biomass was 3.39× greater in native grass fields than in OWB monocultures. Native grass fields provided habitat for a larger complement of birds than did OWB monocultures, and reduced food availability in OWB fields ...