Natural Vegetation Cover Research Articles

Response of Natural Vegetation to Climate in Dryland Ecosystems: A Comparative Study between Xinjiang and Arizona

As one of the most sensitive areas to climate change, drylands cover ~40% of the Earth’s terrestrial land surface and host more than 38% of the global population. Meanwhile, their response to climate change and variability carries large uncertainties as induced by background climate, topography, and land cover composition; but there is a lack of intercomparison of different dryland ecosystems. In this study, we compare the changing climate and corresponding responses of major natural vegetation cover types in Xinjiang and Arizona, two typical drylands with similar landscapes in Asia and North America. Long-term (2002–2019) quasi-8-day datasets of daily precipitation, daily mean temperature, and Normalized Difference Vegetation Index (NDVI) were constructed based on station observations and remote sensing products. We found that much of Xinjiang experienced warming and wetting trends (although not co-located) over the past 18 years. In contrast, Arizona was dominated by warming with insignificant wetting or drying trends. Significant greening trends were observed in most parts of both study areas, while the increasing rate of NDVI anomalies was relatively higher in Xinjiang, jointly contributed by its colder and drier conditions. Significant degradation of vegetation growth (especially for shrubland) was observed over 18.8% of Arizona due to warming. Our results suggest that responses of similar natural vegetation types under changing climate can be diversified, as controlled by temperature and moisture in areas with different aridity.

Native and non-native understory vegetation responses to restoration treatments in a dry conifer forest over 23 years

Restoration of fire-prone forests is a common practice intended to increase resilience to wildfire, drought, and bark beetles. However, the long-term effects of restoration treatments on understory species, particularly non-native species, are poorly understood. We investigated long-term (23 years) effects of restoration treatments on native and non-native understory vegetation at the Lick Creek Demonstration-Research Forest, a ponderosa pine/Douglas-fir forest in western Montana, USA. Restoration treatments included shelterwood-with-reserves harvesting implemented alone or in combination with prescribed burning under either wet or dry conditions, plus a no-action control. Changes in understory vegetation cover and species richness (measured pre-treatment, 2, 3, 4, 5, 15, and 23 years post-treatment) were analyzed by growth form (forb, graminoid, and shrub) and origin (native vs. non-native) to test how understory dynamics respond to disturbance intensity. We also accounted for basal area of trees to consider how differential overstory conditions affected final treatment responses. Native vegetation cover responses followed predictable successional patterns: after initial declines by grasses and shrubs immediately after disturbance (43% and 40% reduction, respectively), all groups increased, peaked about five years after disturbance (74% greater than pre-treatment on average) and then generally declined to levels similar to pre-treatment. The magnitude of these changes was related to the disturbance intensity (i.e., cut-and-dry-burn > cut-and-wet-burn > cut-and-no-burn > control). For all native groups, variation in tree basal area at year 23 explained remaining differences among treatments. Non-native grasses and forbs followed similar overall trajectories, but cover of these groups increased immediately after treatment and rose more steeply to their peak five years post-treatment (12 times greater than pre-treatment on average), with differences persisting through year 23. While non-native cover responses in year 23 were negatively correlated with tree basal area, as seen for native taxa, overstory conditions alone did not fully account for differences between burned and unburned treatments. This suggests that effects of burning unrelated to tree regeneration favored non-natives. Nonetheless, in the last sampling year treatment-induced increases in non-native cover were modest, suggesting that after 23 years understory responses in this forest type were fairly resilient to restoration treatments. However, because forest structure and composition were reverting to pre-treatment conditions by year 23, retreatment may be necessary at intervals of <23-years in our system, which could exacerbate non-native responses. Results of our long-term experiment provide insight into how different forest restoration treatments and their timing may affect understory susceptibility to non-native plant invasion.

Effects of Lantana camara invasion on vegetation diversity and composition in the Vhembe Biosphere Reserve, Limpopo Province of South Africa

Although the effects of invasive alien plants on natural ecosystems are widely acknowledged, the effects of specific plant species can be context dependent. The study examined changes in native vegetation diversity and composition following Lantana camara invasion at different cover conditions in the Vhembe Biosphere Reserve, Limpopo Province of South Africa. Using a comparative approach, native vegetation diversity, cover, and composition were compared in L. camara high and low cover and uninvaded conditions, on three replicated sites, each with five 10 × 10 m plots. Results show that vegetation diversity (species richness, Shannon-Wiener, and evenness index) were significantly higher in the uninvaded condition than in the L. camara high and low invasion conditions. Species relative cover was significantly higher in uninvaded condition than in L. camara high and low invasion conditions, though it decreased gradually along the invasion cover gradient for trees and shrubs as well as forbs. Analysis of similarities showed significant separations in vegetation composition among the three invasion conditions for all the growth forms, with most woody alien plants, e.g. Acacia mearnsii, Rubus rigidus, and Caesalpinia decapetala being associated with L. camara high and low invasion conditions. The study concludes that invasion by L. camara was associated with changes in native vegetation diversity, cover, and composition, with observed changes being more visible under L. camara high as compared to low invasion condition. The presence of L. camara at high cover condition significantly decreased native species diversity and composition, an indication that impacts of L. camara invasion are cover dependent. From a management standpoint, the study suggests the removal of L. camara, however such removal should consider protecting the co-occurring native species. This study offers a baseline for further research to determine mechanisms responsible for native vegetation change associated with L. camara invasion.

What does Atlantic Forest soundscapes can tell us about landscape?

The ecoacoustics approach for environmental recordings analysis is used to understand and identify big ecological patterns related to different sound sources, like animals, humans and the environment itself. Sounds can vary according to several features that can be on its surroundings or far away, therefore they are very much reliant on scale. Because humans are changing the environment so much and we cannot account for all those changes in the same speed as they happen, we need fast evaluation tools, such as remote sensing and acoustic monitoring (considered the equivalent of spatial remote sensing for sounds). Considering that the scale of effect was never measured for soundscapes before, we aimed to see in what scale different acoustic indices were responsive. Also, we tested how acoustic indices are influenced by natural vegetation cover. We recorded environmental sounds in Atlantic Forest fragments during three months on the rainy season. Then we calculated different acoustic indices and the percentage of natural vegetation cover in different scales. Our results corroborated our initial hypotheses: different indices respond to different scales and their medians varied according to the amount of vegetation cover on the surroundings. More studies are needed with less fragmented areas, to test indices behaviour in a continuum, but we consider this work an important starting point to understand acoustic indices behaviour in tropical areas, especially in such degraded and threatened area as Atlantic Forest.

Higher infection probability of haemosporidian parasites in Blue-black Grassquits (Volatinia jacarina) inhabiting native vegetation across Brazil.

Human induced changes on landscape can alter the biotic and abiotic factors that influence the transmission of vector-borne parasites. To examine how infection rates of vector-transmitted parasites respond to changes on natural landscapes, we captured 330 Blue-black Grassquits (Volatinia jacarina) in Brazilian biomes and assessed the prevalence and diversity of avian haemosporidian parasites (Plasmodium and Haemoproteus) across avian host populations inhabiting environment under different disturbance and climatic conditions. Overall prevalence in Blue-black Grassquits was low (11%) and infection rates exhibited considerable spatial variation, ranging from zero to 39%. Based on genetic divergence of cytochrome b gene, we found two lineages of Haemoproteus (Parahaemoproteus) and 10 of Plasmodium. We showed that Blue-black Grassquit populations inhabiting sites with higher proportion of native vegetation cover were more infected across Brazil. Other landscape metrics (number of water bodies and distance to urban areas) and climatic condition (temperature and precipitation) known to influence vector activity and promote avian malaria transmission did not explain infection probability in Blue-black Grassquit populations. Moreover, breeding season did not explain prevalence across avian host populations. Our findings suggest that avian haemosporidian prevalence and diversity in Blue-black Grassquit populations are determined by recent anthropogenic changes in vegetation cover that may alter microclimate, thus influencing vector activity and parasite transmission.

Effectiveness and costs of invasive species control using different techniques to restore cerrado grasslands

Invasion by exotic grasses is a severe threat to neotropical grasslands conservation and a major challenge for their restoration. To restore fire‐prone cerrado grasslands in southeastern Brazil, which have been massively invaded by the African grass Urochloa decumbens, we tested prescribed fire, herbicides, and hoeing, by themselves or in different combinations. Techniques were compared using ecological indicators (decreasing invasive and increasing native vegetation cover and richness) and cost‐effectiveness. All treatments, except fire alone, were similarly effective in controlling the invasive grass, which was reduced to less than 5% cover after 2 years. However, only hoeing was effective in recovering both ground cover and richness of the native vegetation, which was the restoration goal. Despite not changing ground cover by native vegetation or alien grasses, fire was successful as a complementary technique, by depleting the seed bank of the invasive grass by 40%. Hoeing preceded by fire and followed by a grass‐selective herbicide was the most cost‐effective, requiring US$40 per hectare to increase native ground cover by one percentage point compared to US$93 per hectare if only hoeing. Despite the low cost and efficacy of glyphosate application for controlling the invasive grass, it must be followed by reintroducing the native ground cover through active restoration. If the restoration target is to recover both structure and richness of the native vegetation without planting, hoeing is the best solution to control alien grasses.

The Grain for Green Project May Enrich the Mercury Concentration in a Small Karst Catchment, Southwest China

The Chinese project, better known as the Grain for Green Project (GGP), has changed the land-use type in the karst area of Puding county, Guizhou province, southwest China, and this study is aimed at evaluating the Hg distribution and determining factors in soils after the land-use change. A total of ten soil profiles were selected in the typical karst region, and the land-use types were divided into native vegetation land (NVL), farmland (FL), and abandoned farmland (AFL). Total Hg concentration under different land-use types increased in the order: NVL (average 63.26 μg∙kg−1) &lt; FL (average 71.48 μg∙kg−1) &lt; AFL (average 98.22 μg∙kg−1). After agricultural abandonment for four to five years with a cover of native vegetation in the AFL, a higher concentration of Hg compared to the other two land-use types indicate that the Hg accumulation in soil results from vegetation restoration of AFL due to land-use change. Soil organic carbon (SOC) and macro-aggregates were highly correlated to Hg concentration in this study. Macro-aggregates can provide a stable condition for Hg due to the thin regolith and high porosity in the karst region. A high proportion of macro-aggregates can reduce the mobility of Hg in the karst area. Intense tillage can significantly reduce the formation of macro-aggregates in FL, but the macro-aggregates in AFL were recovered as well as those in NVL, resulting in the accumulation of Hg.

Reconciling coffee productivity and natural vegetation conservation in an agroecosystem landscape in Brazil

Politicians have approved significant changes to the Brazilian Forest Code (Brazilian Law n. 12.651/2012), providing partial pardons for illegal deforestation in 2012. Nonetheless, the New Forest Code (NFC) may cause economic harm, since ecosystem services may be affected, and the productivity of several crops may end up decreasing. Here, we explored two sets of factors, one at a narrow-scale – the loss of close natural vegetation cover – and another at a wide-scale considering implications at a landscape level to measure the effects of the presence/absence of forest remnants, and consequently, of pollinators, on coffee productivity. The narrow-scale perspective used manipulative experiments in ten coffee plantations, and the wide-scale perspective considered secondary data on coffee productivity in planted and native forests of 61 municipalities to test the hypotheses: i) coffee branches with pollinator access are more productive; ii) coffee crops in contact with native forest remnants are more productive; iii) coffee plants located near to native forest remnants are more productive; iv) coffee productivity increases with the municipality area occupied by native forest remnants, and, v) coffee productivity decreases with the municipality area occupied by Eucalyptus spp. At the narrow-scale, we detected 32 % higher coffee productivity when pollinators were present (hypothesis i) and 15 % higher productivity when forest remnants were in contact with the plantation (hypothesis ii), but no differences related to forest remnants in the broader area (hypothesis iii). At the wide-scale, we observed that a higher amount of native forest cover increased coffee productivity (hypothesis iv), while increased Eucalyptus spp. plantations reduced coffee productivity (hypothesis v). The corroboration of hypotheses i, ii, and iv illustrates the importance of animal pollination and native vegetation remnants fr coffee productivity. The findings for hypothesis v reinforce that Eucalyptus spp. plantations are not good surrogates for native vegetation as part of management recovery action for deforested areas. Following the New Forest Code’s recommendations in Article 22 (Chapter IV, Section II), the preservation of native vegetation, species diversity, and native species regeneration should be attended to in legally instituted natural reserves. Our findings improve discernment that natural areas' devastation or its coverage using planted forest may reduce productivity levels of coffee plantations, representing a disruption of natural complexity, of organisms' connectivity, and consequently of ecosystem services as the pollination and pollinator-dependent crops' productivity, as the coffee.

Density and diversity of macroinvertebrates in Colombian Andean streams impacted by mining, agriculture and cattle production.

BackgroundMining, agriculture and cattle production are activities that threaten the quality and quantity of water resources in the Colombian Andes. However, many drainage basins in this region have not been subjected to simultaneous evaluation of the impact these activities have on the density, diversity and composition of aquatic macroinvertebrates (AMI). The first two of these ecological variables are expected to decrease drastically from zones with no apparent impact towards areas with anthropogenic activity, which areas with mining will present the most impoverished AMI community.MethodsWe evaluated the density, diversity and composition dissimilarity of AMI in streams impacted by gold mining, agriculture and cattle production. Two reference streams were also studied. Six benthic samplings were conducted bimonthly (Feb 2014–Feb 2015) using a Surber net. Water samples were taken in order to make environmental evaluation among the aforementioned streams, including hydrological, physicochemical and bacteriological parameters (HPCB). Diversity was evaluated as the effective number of RTUs—recognizable taxonomic units—by comparing the richness, typical diversity, and effective number of the most abundant RTUs. Compositional dissimilarity was examined with nMDS and CCA analysis.ResultsA total of 7,483 organisms were collected: 14 orders, 42 families and 71 RTUs. Our prediction regarding the density and diversity of AMI (Reference > Cattle production > Agriculture > Mining) was partially fulfilled, since the agriculture-dominated stream presented a more impoverished AMI community than that of the gold mining stream. However, these streams presented lower diversity than the cattle production and reference streams, and the AMI density only differed significantly between one reference stream and the agriculture stream. The AMI composition in the agriculture-dominated stream clearly differed from that of the other streams.DiscussionThe observation of a more impoverished AMI community in agricultural production areas compared to those with mining or cattle production may reflect the importance of the remaining riparian vegetation, which was scarce at the stream with agricultural activity. Moreover, the low diversity, and mainly the reduced AMI richness, in the agriculture stream coincided with the absence of insect genera are intolerant to deterioration of the biological and physicochemical conditions of the water (e.g. Anacroneuria).ConclusionsThe results suggest that the local impact of agricultural activities may be of equal or greater magnitude than that of mining in terms of AMI density, diversity and composition, in the Colombian Andean riverscape. Future studies should systematically evaluate, throughout the annual cycle, the relative effects of the productive land use, the remaining native vegetation cover and the consequent changes in the HPCB parameters of the water on AMI communities in Colombian Andean basins.

Three decades of land-use and land-cover change in mountain regions of the Brazilian Atlantic Forest

Mountain regions are key hotspots for biodiversity conservation and for provisioning ecosystem services. Containing fragile ecosystems and home to millions of inhabitants, mountains are also places of great value for tourism, cultural practices and endemic species. In this paper, we developed the first multitemporal land-use and land-cover assessment of mountain regions within the Brazilian Atlantic Forest (BAF), the most endangered Brazilian tropical biome. The study used spatial thematic mapping for 1985, 2001, and 2018 to understand changes in landscape composition, patterns of change in patch metrics of natural vegetation cover, and correlations between human population and natural vegetation. Change detection techniques, landscape metrics and statistical tests (e.g., Kruskal-Wallis) were applied. We found that landscape composition did not change at significant levels over the 34 years (1985–2018), but that intense exchange between natural vegetation and agriculture creates a shifting mosaic steady-state. Additionally, natural vegetation loss was 13-fold lower within mountains than in other areas of the BAF biome, which indicates lower human-induced change in mountain regions. Urban and rural population (number of inhabitants) showed positive correlation with natural vegetation at municipality level indicating higher presence of population in municipalities with large extents of natural vegetation. Analysis demonstrated that the study region was under lower population pressure and urban growth compared to other areas and had kept large extents of natural vegetation within large patches, different to what is observed at biome level. However, telecoupling processes may result in indirect land changes in mountain regions of the BAF biome. Our results indicate that mountains play a key role in conserving the remnants of the BAF.

Iron ore mining areas and their reclamation in Minas Gerais State, Brazil: impacts on soil physical properties

Plant cover acts to maintain the balance between soil chemical, physical, and biological attributes, as well as superficial soil protection. The aim of this study was to evaluate the impacts of iron ore mining and their reclamation on soil physical properties and soil visual quality in Fort Lauderdale Municipal Park and Serra do Curral Municipal Park, Iron Quadrangle (Quadrilatero Ferrifero), Minas Gerais State, Brazil. The evaluated areas varied in relation to the post-mining condition, natural revegetation (NR), an area with gully erosion (GA) and area under eucalyptus revegetation (ER) and native vegetation cover, rupestrian field (RF), and seasonal semi-deciduous forest (NF). The main soil physical attributes evaluated were: soil organic matter (SOM), geometric mean diameter (GMD), weighted mean diameter (WMD), bulk density (Bd), air capacity (ACb), plant-available water capacity (AWC), relative field capacity (RFC), and visual soil quality assessment. In addition to the impacts on the landscape, with removal of vegetation and soil cover, iron ore mining process impacts soil physical quality measured through porosity and aggregation properties and therefore could impact ecosystems services. Areas of iron post-mining that are not restored can develop gully erosion. NR shows high erosion risk inferred through aggregation indicators (GMD = 3.84 mm; MWD = 3.04 mm), despite similar soil organic matter content and higher plant-available water and air (NR [AWC = 0.102 m3 m−3; ACb = 0.328 m3 m−3], NF [AWC = 0.062 m3 m−3; ACb = 0.202 m3 m−3]) compared with NF (GMD = 4.77 mm; MWD = 4.56 mm). ER had similar soil structure stability compared to NF as well most of the porosity indicators, which is associated with the higher soil organic matter. Soil visual assessment alone was not able to characterize the soil physical quality, mainly in the post-mining areas, because it was designed for agricultural soils.

Assessing the legacy of land use trajectories on stream fish communities of southern Brazil

Loss of native vegetation cover in the watershed is known to affect stream fish communities. However, community response may not occur immediately after land cover change, and may become apparent only years later. In this study, we investigated how a c.a. 30-year (1985–2017) historical trajectory of native vegetation loss affected fish communities in 47 streams of southern Brazilian grasslands. We tested whether current species richness and composition would be more related to past or to recent natural vegetation cover. We then defined trajectories of vegetation loss and tested whether different attributes (frequency, magnitude and duration of disturbance) affected particular species and functional groups. We found that current species richness and composition were more related to past than to current vegetation cover. However, we also observed that responses of particular species and functional groups were dependent on specific trajectory attributes. We concluded that present fish community characteristics may respond not only to past watershed conditions but also to how watershed conditions have changed over the time. Exploring land use trajectories seems a promising approach for improving our understanding of landscape effects on stream ecosystems, as well as the predictability of present landscape management and planning on freshwater communities.

Desertification risk assessment in Northeast Brazil: Current trends and future scenarios

AbstractDesertification is one of the major environmental problems that humanity faces today, since it reduces the availability of ecosystem services, increases food insecurity and poverty, and affects the wellbeing of societies. The analysis of the process is extremely complex, since the phenomenon takes place at different temporal and spatial scales, influenced by different factors. It is widely recognized that land use/land cover change (LULC) is one of the main drivers of desertification since environmental degradation is always triggers by the removal of natural vegetation cover. In this study, a LULC change model was calibrated and validated using climate model simulations, demographic data and land susceptibility maps for the historical period 2000–2010. Then, desertification susceptibility of the Northeast of Brazil were estimated by integrating LULC trajectories with three different downscaled climate change scenarios and projection of population growth for the period 2015–2025, 2025–2035, and 2035–2045 for the emission scenarios RCP4.5 and RCP8.5. Results indicated that, between 2010 and 2035–2045, areas of moderate susceptibility decreased 10.34%, while areas of high susceptibility increased 12.28% in the case of the RCP4.5. For the RCP8.5 scenario, those numbers are −16.85% for moderate susceptibility, and +19.62% for high susceptibility. Among all indicators included in the analysis, land management was the main driver of desertification susceptibility, which indicates that mitigation and adaptation strategies for the region should pursue sustainable land use policies.

Assessing multidimensional sustainability: Lessons from Brazil’s social protection programs

Examining linkages among multiple sustainable development outcomes is key for understanding sustainability transitions. Yet rigorous evidence on social and environmental outcomes of sustainable development policies remains scarce. We conduct a national-level analysis of Brazil's flagship social protection program, Zero Hunger (ZH), which aims to reduce food insecurity and poverty. Using data from rural municipalities across Brazil and quasi-experimental causal inference techniques, we assess relationships between social protection investment and outcomes related to sustainable development goals (SDGs): "no poverty" (SDG 1), "zero hunger" (SDG 2), and "health and well being" (SDG 3). We also assess potential perverse outcomes arising from agricultural development impacting "climate action" (SDG 13) and "life on land" (SDG 15) via clearance of natural vegetation. Despite increasing daily per capita protein and kilocalorie production, summed ZH investment did not alleviate child malnutrition or infant mortality and negligibly influenced multidimensional poverty. Higher investment increased natural vegetation cover in some biomes but increased losses in the Cerrado and especially the Pampa. Effects varied substantially across subprograms. Conditional cash transfer (Bolsa Familia [BF]) was mainly associated with nonbeneficial impacts but increased protein production and improved educational participation in some states. The National Program to Strengthen Family Farming (PRONAF) was typically associated with increased food production (protein and calories), multidimensional poverty alleviation, and changes in natural vegetation. Our results inform policy development by highlighting successful elements of Brazil's ZH program, variable outcomes across divergent food security dimensions, and synergies and trade-offs between sustainable development goals, including environmental protection.

Avaliação ambiental da qualidade limnologica e de sedimentos em córrego do Centro Oeste do Brasil

O estudo teve como objetivo avaliar qualidade limnologica no córrego Curral de Arame, determinar concentrações de metais na água e nos sedimentos, avaliar se os tipos de uso e cobertura do solo interfere na qualidade aquática. Além de correlacionar o uso e a cobertura do solo em relação as concentrações de metais na água entre os períodos seco e chuvoso e investigar os potenciais riscos não-carcinogênicos de metais na água para a biota aquática. Os valores do pH, no período seco foram inferiores ao limite estabelecido pela legislação brasileira na porção média e baixa do córrego. O Fe na água ultrapassou o limite estabelecido pela resolução brasileira, nos quatro locais. As concentrações de metais nos sedimentos estavam dentro dos limites seguro para a vida aquática. O córrego Curral de Arame apresentou a vegetação ciliar reduzida em alguns locais, decorrente da expansão de atividades agrícolas. Constatamos, nos períodos seco e chuvoso, correlação negativa entre as proporções de agricultura e fragmentos florestais, mostrando quando há aumento de áreas agricultáveis ocorre o inverso a redução da cobertura vegetal nativa. No período chuvoso, houve correlação negativa e significativa, entre os fragmentos florestais em comparação ao Fe na água no córrego Curral de Arame, demostrando quando há maiores aporte de vegetação reduz o carreamento de contaminantes no curso do sistema aquático. No córrego Curral de Arame, nos períodos seco e chuvoso, apresentou risco não-carcinogênica na água para a biota aquática em relação aos valores de Fe. Neste sentido, o córrego Curral de Arame está passando por algum tipo de estresse ambiental, principalmente devido a redução da cobertura vegetação nativa no entono deste ambiente aquático.

MONITORING OF FOOTHILL AND MOUNTAIN PASTURE PLANTS OF KASHKADARYA BASIN

This article reveals the data about the level of pasture degradation in Kashkadarya basin foothills and mountains, so weak, moderate and strong degradation processes of pastures and average natural vegetation cover in all seasons are described. Mesophytes are mainly plant species that are more adapted to moderate humidity and average temperature, most of which are ephemeral and ephemeroides. They are mainly widespread on the hills and ones are the main fodder base in the spring. The most spread of these are: Carex pachystilis, Poa bulbosae, Vulpia heredity, Bromus oxydon, Taeniaterum critinum, Cryptospora falcate, Strigosella scorpioides, Romeria refracta and others. Some of the ecological groups are wide distributed on the banks of rivers, streams and ditches, and continue to grow in spring, summer and autumn such as Trifolium repens, Equisetum arvense, E. ramosissimum, Poa pratensis and others. Many of them are typical of the boreal flora, they are grown in all regions of the country and do not occupy a wide area. Hygromesophytes are moderately ecomorphic and ones are a complex of hygrophytes and mesophytes. This group is also more grown in humid areas, such as Phragmites australis, Carex stenophulloides, Cyperus rotundus and others. Halophytes grow in saline soils, and salinization is rare in the adyr and mountain height stages. Salsola scleranta, Girgensohnia oppositiflora, Halocharis hispida and others are found in saline soil communities in adyr pastures. Besides the description and distribution of plants, preparation and quality of raw sources; chemical composition, indicators of application of the medicinal plants in the pharmaceutical industry have been analyzed.

Dynamics of Farmland Birds in Traditional Agroecosystems: The Value of Countryside Elements in Avian Conservation

In India, urbanization and growth of cities have fragmented farmlands and the area under cultivation is dwindling. This study examined the ecological characteristics of rice fields, the inherent value of countryside elements and the relative occurrence of four species of farmland birds Dicrurus macrocercus, Turdoides affinis, Pavo cristatus, and Psittacula krameri along the Cauvery delta region, widely known as the granary of Tamil Nadu. The abundance and distribution of birds were analyzed at 30 sampling points for a year using the unlimited-radius point-counts. Among the four species recorded, D. macrocercus utilized more heterogeneous farmlands, while P. krameri was recorded in more intensively cultivated regions of the farmland. Pre-harvested rice fields predominantly supported species abundance and richness and exhibited a greater value for farmland birds than plowed, flooded or post-harvested fields. The abundance and richness of birds in agroecosystems increased with native vegetation cover and woody shelterbelts. D. macrocercus displayed greater tolerance towards monoculture plantations and elements within the mosaics like cable poles and power lines. Bird abundance in farmlands also correlated positively with decreasing distance from the mainland for D. macrocercus and T. affinis and showed a negative correlation for P. cristatus and P. krameri. D. macrocercus also displayed specialized resource utilization foraging techniques coinciding with cultivation activities resulting in bird-farmer mutualism. Cross-validation of the AIC models also showed that rice fields margined by greater amounts of vegetation cover and retention of species-specific modified elements supported the greatest abundance of farmland birds.

SPATIO-TEMPORAL CHANGES IN THE STRUCTURE OF THE ANT, BEE, AND TREE COMMUNITIES IN THE BRAZILIAN CERRADO

In this study, we described the changes in land cover and land use, in climate, and in the incidence of fires that have occurred over the last decades within the region of the “Triângulo Mineiro and Southeastern Goias” site (TMSG) of the Long-term Ecological Program (PELD-CNPq). We also evaluated to what extent some stressors, such as habitat fragmentation, fire events and the creation of artificial dams, are related to temporal changes in the communities of euglossine bees, ants and trees. We detected abrupt changes in both climate and native vegetation cover in the TMSG region. Since 2000, the area occupied by native vegetation has declined from 34.5 to 25.5 % while the incidence of fires increased exponentially. Moreover, the annual maximum temperature is 2.5 °C higher than it was about 30 years ago. Temporal changes in the composition of the euglossine community in forest fragments (varying in size from 16 to 200 ha) were gradual and non-directional, suggesting that the community is in equilibrium. For arboreal ants associated with savannas, our data also indicate an absence of directionality in the community trajectory. However, there is evidence that changes are no longer gradual in the presence of recurrent fire events. In contrast, the tree communities showed gradual and directional changes, indicating the existence of a successional process in these communities. These changes started, in one case, by the construction of a reservoir along the margin of the forest fragment and, in the other, by the suppression of anthropic disturbances when the fragment became part of a protected area.

A TEMPORAL LAND USE / LAND COVER CHANGE DETECTION IN MANJERI MUNICIPALITY, MALAPPURAM DISTRICT, KERALA

The land is one of the important natural resource next to water, for man to survive on earth. The land use / land cover studies help to understand about a natural vegetation cover over an earth surface and how and up to what extent man is utilizing a land cover for his economic benefit in an area. The present study deals with the land use / land cover change detection in Manjeri municipality, Malappuram district in Kerala. This not only study the existing land use / land cover pattern over the study area but also analyze the level of changes that happened within the span of 47 years. It also clarifies the causes for such changes and suggests remedial measures to overcome such problems. Hence this study will be very beneficial for the study related to natural resource management, regional planners and decision makers regarding sustainable development of Manjeri municipality in Malappuram district, Kerala. Keywords: Land use; Land cover; Manjeri; GIS &amp; Remote sensing

Fragmentação da vegetação da bacia hidrográfica do Rio Marapanim, nordeste do Pará

A fragmentação florestal é uma das principais consequências das atividades antrópicas em áreas de vegetação nativa. Quando considerada a abordagem de bacias hidrográficas, a fragmentação pode aumentar processos erosivos e alterar o regime hídrico, notadamente em decorrência das ações de desmatamento. Assim, no presente estudo buscou-se analisar a estrutura da paisagem da bacia hidrográfica do rio Marapanim-PA, com o enfoque na fragmentação da vegetação arbórea. Para isso, foi utilizada uma cena do satélite Landsat 8, sensor OLI, adquirida em 2017 e classificada usando o algoritmo da Máxima Verossimilhança a fim de classificar e estimar os diferentes usos e coberturas da terra em 2017 na área da bacia. Subsequentemente, realizou-se a análise dos fragmentos florestais utilizando as métricas da paisagem em nível de mancha (patch), classe (class) e paisagem (landscape). Os resultados indicam que a paisagem da bacia hidrográfica é majoritariamente composta por vegetação arbórea (49%) e áreas de agricultura (29%), responsável pelas principais alterações na cobertura vegetal nativa da bacia estudada. O estudo da quantificação e caracterização da estrutura da paisagem mostrou que a paisagem da bacia se encontra muito fragmentada, com um total de 16.697 fragmentos. O tamanho médio dos fragmentos é de 12,79 ha, considerado de valor mediano para conservação da biodiversidade. A classe de vegetação arbórea é a mais fragmentada, representando 41,36% do total de fragmentos da paisagem da bacia. O índice de forma desses fragmentos é de 1,56, indicando a predominância de formas mais irregulares e, portanto, mais susceptível aos efeitos de borda. Os resultados deste estudo podem subsidiar a formulação de ações e/ou políticas públicas visando promover a recuperação e manutenção dos fragmentos da vegetação arbórea da bacia hidrográfica do rio Marapanim no estado do Pará.