Secondary Forest Vegetation Research Articles

Disturbance Level Mediates the Differential Resistance of Tropical Dry Forest Soil and Vegetation Attributes to High-Intensity Hurricanes

Hurricanes are extreme climatic events frequently affecting tropical regions such as the tropical dry forests (TDFs) in Mexico, where its frequency/intensity is expected to increase toward the year 2100. To answer how resistant is a Mexican tropical dry forest to a high-intensity hurricane, and if its degree of resistance was mediated by its conservation degree, we evaluated the effect of a category 4 hurricane over the tree community, soil nutrients, and soil enzymatic activity in two contrasting TDF ecosystems: Old-Growth Forest (OGF) and Secondary Forest (SF). In general, vegetation richness and diversity showed very high resistance one year after the hurricane, but several structural attributes did not, especially in the OGF where the tree mortality related to vegetation structure and spatial distribution of individuals was higher. Then, in the short term, SF vegetation appeared to be more resistant, whereas the OGF, with more biomass to lose, appeared to be more vulnerable. Conversely, most soil attributes showed low resistance in both stages, but especially in SF which could face more severe nutrient limitations. The response of TDF to high-intensity hurricanes, in terms of above- and belowground processes, was in part dependent on its disturbance level. Moreover, an increase in the intensity/frequency of hurricanes could lead this TDF toward a high nutrient limitation (especially by phosphorus) for the plants and consequently toward a loss of soil functioning, especially in the SF. This eventually could produce a severe degradation in fundamental attributes and functions of the ecosystem.

KELIMPAHAN JENIS VEGETASI HUTAN SEKUNDER BEKAS KEBAKARAN DI DESA KAMAL KABUPATEN SERAM BAGIAN BARAT

The forest area of ​​Kamal village is included in secondary forest with convertible production forest land cover. The study was carried out in July – August 2020 using a combination of the strip method and the plotted line method to calculate the overall stand based on the growth rate in an area of ​​10,000 m2 with the condition of vegetation having succession due to forest fires in 1992 causing low biodiversity characterized by the dominance of species – types of secondary forest vegetation. Vegetation analysis results obtained 47 tree species with 29 families occupying all growth stages with the highest dominance controlled by species; marong merah (Commersonia bartramia), damar hitam (Canarium asperum Benth), red wood (Eugenia sp), kayu kikir (Eugenia sp) and pala hutan (Myrestica sp). Species Diversity Index (H') for tree level is 1.44% dominated by damar hitam (Canarium asperum .Benth), pole H' value is 1.16% dominated by Kenanga (Cananga odorata .Hook), Sapihan H' value was 1.13% dominated by damar hitam species (Canarium asperum Benth) while the Seedling rate H' value was 0.93% and dominated by damar hitam species (Canarium asperum .Benth). Based on the value of H' from various levels of growth, the diversity of wood forest products was categorized for the secondary forest research location after the fire in Kamal village was in the medium category with the condition of the species in each type of vegetation that was found to have developed and could survive for increased sustainability

Factors Affecting Avifaunal Diversity in Selected Agro-Ecosystems of Himachal Pradesh Agricultural University, Palampur, Himachal Pradesh, India

Avifaunal diversity in eight different habitats of Himachal Pradesh Agricultural University, Palampur was studied in order to find factors affecting the occurrence of bird species. Bird populations were sampled in different agro-ecosystems such as farm fields (experimental and organic), wetland, abandoned tea plantation, administration area, playground, secondary forest and stream vegetation. A total of 125 species of birds belonging to 51 families, including 33 winter visitors and 27 summer visitors have been recorded. Among them, 78 insectivores followed by 18 carnivores were recorded. The abandoned tea field was a diverse habitat that maintained the highest species richness recording 50 species, followed by stream vegetation and organic farm. Seasonal variations and habitat heterogeneity play crucial role in shaping species richness. Plant diversity, vegetation structure and microhabitats support different feeding guilds, temporary refuge and migratory route which result in increased bird diversity. Based on different categories of birds, the cluster analysis revealed three distinct clusters of habitats, first cluster containing administration area and secondary forest habitats, experimental farm and wetland grouped in cluster II, whereas cluster III contained habitats viz. abandoned tea plantation, playground, organic farm and stream vegetation. Several conservation measures such as increasing plant diversity, conducting regular and long-term systematic studies, introducing bird friendly management plan are recommended to conserve and enhance avifaunal diversity in the university.

冀北山地天然次生林土壤生态化学计量特征及影响因素

为了探究天然次生林植被及立地因子对土壤养分含量的影响，量化植被与立地因子对土壤养分的影响比例，为合理抚育冀北山区次生林，提高次生林生产力提供依据，以冀北山地分布的天然次生林为研究对象，选取代表性的地段并设置面积为20 m×20 m的样地，以均匀布点与多点混合为原则，按照0-20、20-40、40-60 cm土层取样。测定土壤pH值、土壤有机碳（Soil organic carbon，SOC）、全氮（Total nitrogen，TN）、全磷（Total phosphorus，TP）、全钾（Total potassium，TK）、速效磷（Available phosphorus，AP）、速效钾（Available potassium，AK）含量，并计算土壤碳、氮、磷计量比。结果表明：不同深度土层土壤TN与SOC之间保持显著相关（P<0.001），SOC、C∶N与AK之间呈显著正相关（P<0.01）；研究区域冀北山地次生林3层不同深度土壤C∶N平均值（27.74、29.96、29.44）与C∶P平均值（158.86、128.63、119.20）明显高于全国土壤C∶N（11.90）与C∶P（60.00）平均值，N∶P平均值（6.45、4.59、4.70）与全国平均水平（3.56）基本相当，对各深度层土壤N∶P值与土壤TN、TP值进行相关性分析发现，TN值与N∶P的相关性更加显著，说明影响N∶P值的主要因素为氮素量的限制。环境因子对3层不同深度土壤的养分指标分别做出48.64%、53.45%及49.23%的解释比例（P<0.001），因子交互后的解释能力相较因子自身的解释能力更强，地形因子与其他因子相交互后，解释比率分别为其单独解释比例的6.45、8.06、3.21倍。从立地条件角度讲，地形因子能够对土壤养分空间分布产生一定的影响，抚育过程中对地形因子的作用应当予以重视。;In order to explore the effects of natural secondary forest vegetation and site factors on soil nutrient concentration, quantify the ratio of vegetation and site factors on soil nutrition, provide a basis for rationally tending secondary forests in the mountainous area of northern Hebei and improving secondary forest productivity, the natural secondary forests distributed in the mountains of northern Hebei Province were selected as the research object and a representative plot was selected and a sample plot with an area of 20m×20m was selected. The principle of uniform distribution and multi-site mixing was adopted when 0-20 cm, 20-40 cm and 40-60 cm soil layer sampling. Soil pH value (Soil pH value), soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), and available phosphorus (AP), available potassium (AK) content were measured in experiment. Based on the results of experiment, soil carbon, nitrogen, and phosphorus stoichiometric ratio were calculated. The results showed that the soil TN and SOC of different depths maintained an extremely significant correlation(P<0.001)among different soil layers, there was also a significant positive correlation between SOC, C∶N and AK(P<0.01).The average values of C∶N ratio of three layers of soils at different depths in the secondary forest in northern Hebei mountainous area (27.74,29.96 and 29.44) and C∶P ratio (158.86, 128.63 and 119.20) were significantly higher than the average level of national soil C∶N (11.90) and C∶P (60.00).Besides, N∶P averages (6.45, 4.59 and 4.70) was basically equivalent to the national average (3.56). The correlation analysis of the soil N∶P value and the soil TN and TP values of each depth layer showed that the correlation between the TN value and the N∶P value was more significant, indicating that the factor why N∶P value was affected was the limitation of nitrogen. Environmental factors accounted for 48.64%, 53.45%, and 49.23% of soil nutrient index of the three layers of soil at different depths (P<0.001). The explanatory power after the factor interaction was stronger than that of the factor itself. After interacting with other factors, the explanatory ratios of terrain factors were 6.45, 8.06, and 3.21 times of the separate ones. From the perspective of site conditions, topographical factors did have a certain impact on the spatial distribution of soil nutrition, and the role of topographical factors in the process of tending should be paid attention to.

The Role of a Water Canal and Secondary Forest for Migrants

Abstract Forests have an important role during migration. They act as ecological corridors and provide resting and feeding places for birds. In our study, we sought to determine whether migratory birds prefer secondary forest or canal vegetation during migration. The study was carried out in Southeast Hungary, in an oleaster forest and in a canal. We used 12 mist nets and the ringing method. The study period lasted from August to October 2016–2018, covering approximately the entire migration period. According to our results, the canal has a significant effect on the species assemblage, as it functions as a migration corridor during migration, most likely not only for diurnal migrants, but for nocturnal migrants as well. Our results showed that the presence of both woody and berry plants had some influence on the species composition. Interestingly, the presence of berries had a positive effect on the presence of insectivorous birds.

Differential air temperature cooling performance of urban vegetation types in the tropics

The tendency for cities to be warmer than surrounding rural areas, known as the urban heat island effect, has become a matter of increasing concern, particularly in regions with a hot, humid climate. While urban vegetation may reduce air temperatures, the magnitude of this cooling effect varies between different types of vegetation. In this study we compared the cooling effect of five vegetation types that are commonly encountered in the tropical city of Singapore: grass, shrub, managed trees, managed trees over shrub, and secondary forest. Ambient air temperatures were monitored over 18 months at 88 locations, and analysed in relation to characteristics of the surrounding vegetation. Generalised additive modelling revealed significant temperature reductions associated with increasing cover of managed trees, managed trees over shrubs below, and secondary forest vegetation, with the latter vegetation type having the greatest effect. We conclude that vegetation can significantly ameliorate temperatures in cities with a hot, humid climate, but not all types of vegetation are equally effective. By demonstrating the cooling benefits of secondary forest in densely-populated urban areas, public education and engagement campaigns could help overcome negative perceptions of such vegetation.

Metals and dissolved organic carbon (DOC) of surface waters in two adjacent watersheds in the eastern Amazon

Land-use intensification in the "Zona Bragantina" region, an area in the eastern Brazilian Amazon, has accelerated landscape changes from primary forest to a mixture of different land uses: native forest (riparian vegetation), secondary forest, pasture, annual cropland, perennial cropland, bare soil and fallow vegetation, with negative consequences for the stability and equilibrium of river systems. This study examined the temporal and spatial variation of dissolved organic carbon (DOC) and metal concentrations in stream water of the Cumaru (ICU) and São João (ISJ) watersheds from May 2014 to April 2015, to understand the chemical changes in forests and agro-ecosystems during one year. In both watersheds, higher concentrations of dissolved metals (aluminum, sodium, barium, calcium, iron, potassium, magnesium, copper and zinc) and DOC were measured in the rainy season, with considerable variability due to precipitation events. Furthermore, strong spatial variation was observed, with lower conductivity, higher pH, and higher concentrations of DOC and dissolved metals in the downstream reaches, especially for DOC in a small reservoir below a dam in ISJ. Significant human intervention was located in these downstream areas, including nearby agriculture and pasture, and use of stream resources for domestic activity. Sandy soil in these areas likely facilitated leachate processes, mainly in deforested areas, supporting the increased movement of metals from the land to the stream.

Assessment of Spatial Variability and Temporal Dynamics of Dissolved Organic Matter (DOM) at Lower Kinabatangan River Catchment, Sabah.

The spatial and temporal variability of dissolved organic matter (DOM) characteristics and surface water quality in the Lower Kinabatangan River Catchment were determined between October 2015 and May 2016. The objectives of this study were: (i) to distinguish the DOM absorption characteristics and physicochemical quality of surface water draining from different types of land use: oil palm plantation (OP), secondary forest (SF) and semi-natural vegetation (SV); and to examine its temporal variations during dry and wet periods. The collected physicochemical parameters data was analysed and classified based on the Malaysian National Water Quality Standard (NWQS). Findings indicated all the parameters fall into Class I, except for pH, total suspended solids (TSS) and concentration dissolved oxygen (DO). Linear discriminant analysis has been applied to distinguished the physico-chemical and absorption DOM properties data into mutually-exclusive spatial and temporal groups. Interestingly, the pH, DO and total nitrogen values were exhibited as dominant parameters at SV during both low and high rainfall periods. The dominance of these parameters suggested that the spatially and temporally varied water quality were influenced by both natural processes (e.g precipitation rate) and anthropogenic factor (e.g land use change). Whereas, both absorption coefficients (a340) and spectral slope (S275-295) were more dominant at SF and OP respectively. This might be due to increasing terrestrial DOM loadings as well as significant degradation of DOM via microbial and/or photochemical reaction.

Regeneração de agroflorestas: a importância da cobertura arbórea na transição florestal

Este estudo analisou e descreveu a composição, riqueza e diversidade de espécies do componente arbustivo-arbóreo nos diferentes estratos florestais de um sistema agroflorestal abandonado (~3 ha), situado em área urbana de Floresta Atlântica, no município de Juiz de Fora (MG), Brasil. Partiu-se da premissa de que o estrato arbóreo remanescente tende a auxiliar o processo de regeneração natural e sucessão florestal. Foram alocadas aleatoriamente 25 parcelas de 20 x 20 m para a análise do estrato arbóreo e subparcelas de 5 x 5 m para a análise do estrato regenerante. Observou-se uma comunidade com forte dominância específica e baixo índice de diversidade de espécies (H’) em comparação com florestas secundárias de mesma fitofisionomia na região. As análises demonstraram que a presença de indivíduos de grande porte que remanesceram no local após o processo de desbaste do sub-bosque tende a auxiliar e acelerar o processo de regeneração natural e sucessão ecológica.

Nitrogen Fixation Inputs in Pasture and Early Successional Forest in the Brazilian Amazon Region: Evidence From a Claybox Mesocosm Study

AbstractThe role of biological nitrogen fixation (BNF) during secondary forest succession and in tropical pastures has been investigated and debated for several decades. Here we present results of a replicated experimental study in a degraded cattle pasture of eastern Amazonia using mass balance and a 15N tracer in lined soil pit mesocosms with three treatments: (1) plant‐free control plots, (2) pasture grass Brachiaria brizantha, and (3) regrowth of early successional secondary forest species. Accumulation of N in grass biomass slightly exceeded estimates of net N mineralization from the plant‐free control plots but was within the margin of error, so inputs of BNF may not have been needed. In contrast, the secondary forest vegetation accumulated about 3 times as much biomass N annually as the net N mineralization estimate, suggesting at least some role for BNF. Based on isotopic and mass measurements of N‐fixing species, BNF was estimated to contribute at least 27 ± 3% of mean annual plant uptake in the secondary forest regrowth vegetation plots. Although BNF is probably important for recuperation of tropical secondary forests following land use change, the majority of the N taken up by both grasses and secondary forest regrowth arose from mineralization of the stocks of soil N.

Species Composition and Structure of Secondary Forest at Nunuka, North Bolaang Mongondow

Secondary forest of Indonesia covered about 24.2 % of total land area and dominated by post logging forest. The discourse to manage all forest area into Forest Management Unit (FMU) as the smallest management unit has been established, including post logging secondary forest. Therefore, understanding the diversity of secondary forest vegetation will help to decide its future management. This research aims to analyze composition, diversity and structure of post logging secondary forest at Nunuka, North Bolaang Mongondow of North Sulawesi. In order to accomplish the proposed objectives 30 plots of 20 m x 20 m were established in research area where number and name of tree species were identified and counted. The research was conducted on November 2014. The result recorded 84 tree species in research area. Anthocephalus macrophyllus dominated tree phase, whereas Eugenia sp. dominated both of poles and sapling. Shannon-Wiener index indicated low and medium diversity, whereas species abundance of tree, ploes and sapling were almost spread evenly. Vegetation density over all vegetation phases was 485.83 tree/ha, the average basal area of the forest was 35.15 m2/ha and the size class distribution did not resembled a reserved J-shaped pattern as found in primary forest. However J-shaped pattern showed in graphs of ten dominant species in both of tree and sapling level.

KOMPOSISI VEGETASI HUTAN SEKUNDER DI NUNUKA BOLAANG MONGONDOW UTARA

Hutan sekunder di Indonesia yang mencakup 24,2% luas daratan Indonesia sebagian besar merupakan bekas pengusahaan hutan. Pemahaman akan vegetasi hutan sekunder bermanfaat dalam menentukan arah pengelolaannya di masa depan. Penelitian ini bertujuan untuk menganalisis struktur, komposisi dan keragaman jenis pohon hutan sekunder bekas pengusahaan hutan di Nunuka Bolaang Mongondow Utara, Sulawesi Utara. Pegumpulan data berupa jumlah dan nama jenis pohon dilakukan dalam plot ukur 20 m x 20 m yang telah dibuat sebanyak 30 buah. Penelitian dilaksanakan pada bulan November 2014 dan tercatat sebanyak 84 jenis. Jenis Anthocephalus macrophylllus mendominasi tingkat pertumbuhan pohon, sedangkan tingkat tiang dan pancang didominasi oleh Eugenia sp. Pohon memiliki keragaman jenis tertinggi sedangkan nilai kelimpahan jenis tertinggi terdapat pada pancang. Kerapatan vegetasi pada seluruh tingkat pertumbuhan sebesar 485,83 individu pohon/ hektar, rata-rata bidang dasar sebesar 35,15 m2/hektar dan kelas distribusi diameter pohon menyerupai bentuk J terbalik. Kata kunci: komposisi, vegetasi, hutan sekunder, Bolaang Mongondow Utara

English

Secondary forest vegetation in the Bragantina area, Northeast of Par&aacute; State, is characterized by the abandonment of anthropized forests, locally known as capoeiras, in different successional stages. The current study aims to evaluate the nutrient concentrations in order to identify the treatment that have caused greater nutrient deficiency due to full and partial litter spacing well as to assess the capoeira with best nutrient cycling performance. The study area is located in 10-and-40-year-old secondary forests in Bragan&ccedil;a County, Benjamin Constant community, Northeastern Par&aacute; State. Litter samples were collected during the dry and rainy seasons. The chemical analysis of the macro and micronutrients were further performed. The decreasing order of the herein observed nutrient concentration was N&gt; Ca&gt; Mg&gt; In&gt; K&gt; P. By taking under consideration the 40-year-old capoeira and the treatments applied to the 10-year-old one (no thinning (NT), partial thinning (PT), and total thinning (TT)), it is possible to state that the highest concentrations in all analyzed elements showed the same descending order in micronutrient concentrations: Fe&gt; Mn &gt; Zn&gt; Cu. The different-aged capoeiras within the Bragantina area showed that not all nutrients were influenced by seasonality, despite the applied thinning type, the vegetation age and the forest species. &nbsp; Key words: Cycling, nutrients, amazon, Northeastern Par&aacute;, Capoeira, thinning.

近308年来大兴安岭北部森林植被气候生产潜力及其对气候变化的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 近308年来大兴安岭北部森林植被气候生产潜力及其对气候变化的响应 DOI: 10.5846/stxb201510312200 作者: 作者单位: 黑龙江省气象科学研究所,黑龙江省气象科学研究所,黑龙江省气象科学研究所,黑龙江省气象科学研究所,黑龙江省气象科学研究所,黑龙江省气象科学研究所,黑龙江省富裕县气象局 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（41165005，40865005）；黑龙江省气象局重点项目（HQZD2015002）联合资助 Climate-induced potential productivity of forest vegetation during the past 308 years in northern Da Hinggan Mountain region, China Author: Affiliation: Heilongjiang Institute of Meteorological Sciences,Heilongjiang Institute of Meteorological Sciences,Heilongjiang Institute of Meteorological Sciences,Heilongjiang Institute of Meteorological Sciences,Heilongjiang Institute of Meteorological Sciences,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:揭示大兴安岭北部气候变化敏感区的气候生产潜力演变及其影响机理，对于维持东北地区生态系统平衡具有重要意义。基于标准树轮年表反演气象资料与研究区13个气象站观测数据组成的1707-2014年气象资料序列，利用Miami模型和小波分析等方法，分析了大兴安岭北部气候生产潜力演变及其对气候变化的响应。结果显示：1707年以来，气温、降水、蒸散和标准气候生产潜力变化均表现极显著增加趋势，标准气候生产潜力（W）变化率为1.79 kg hm-2 a-1，20世纪气候倾向率最大为10.14 kg hm-2 a-1，温度气候生产潜力（WT）与降水气候生产潜力（WR）的比值21世纪最大，水热配比状态最好；4种气候生产潜力存在不同时间尺度的周期变化，但变化一致性较好，主周期均为215-219a；大兴安岭北部W呈现一致的正变化趋势，高值、次高值、低值中心分别在根河、塔河、鄂伦春偏南地区，振幅由西北向东南逐渐递减；W与年气温、降水量、蒸散量正相关显著，年平均气温每升高1℃、年降水量和蒸散量均增加10 mm，W变化率依次为453.71、74.40、219.01 kg/hm2，且气温是影响W的主要因子；未来"暖湿型"气候对森林植被生长有利，而"冷干型"气候对森林植被生长不利，气候生产潜力增加（减少）幅度均为10.9%-21.7%。研究结果不仅可为区域尺度内研究森林植被气候生产潜力提供基础方法，而且对进一步估算森林碳汇、即将实施的碳交易及中国北部边疆生态安全研究和生态功能规划制定等具有重要参考价值。 Abstract:Understanding the evolution and mechanisms of climate-induced potential productivity in the climate change sensitive regions of northern Da Hinggan Mountain are fundamental for maintaining the ecosystem balance of northeastern China. The present study employed a meteorological data series from 1707 to 2014 by using standard tree-ring chronology data collection methods and observations from 13 weather stations in northern Da Hinggan Mountain region. Using a Miami model and wavelet analysis, we analyzed the evolution of climate-induced potential productivity and its response to climate change. Results show that four types of climate-induced potential productivity (air temperature, precipitation, evapotranspiration, and standard climate-induced potential productivity (W)) have increased significantly(P ≤ 0.001) since 1707. W has increased at a rate of 1.79 kg hm-2 a-1 in this region since 1707. During the 20th century, the change rate of W caused by climate change peaked at 10.14 kg hm-2 a-1. During the 19th century, the change rate of W caused by climate change reached a minimum of 0.50 kg hm-2 a-1. These values of W were in the mid-range for the 18th (0.66 kg hm-2 a-1) and the 21st (4.79 kg hm-2 a-1)) centuries. The value of W for the analyzed centuries was ranked as the 21st > 20th > 18th > 19th century. The ratio of temperature potential productivity (WT) to precipitation potential productivity (WR) peaked in the 21st century; this century also experienced the highest correlation between precipitation and temperature. The different time scales in the four types of climate-induced potential productivity changed periodically in the wavelet analysis, but was relatively consistent. The first major periodic oscillation of the wavelet analysis was 215-219 years, and other major periodic oscillations in wavelet analysis were at 138, 138, 136, 138 years. W showed a consistently positive trend in northern Da Hinggan Mountain, high, sub-high, and low values of W in Genhe, Tahe, and southern Elunchun Counties of northern Da Hinggan Mountain, respectively. That is, the amplitude of the W gradually decreased from northwest to southeast. Therefore, the geographical environment greatly influenced the value of W as it varied significantly across the region. Climate-induced potential productivity was relatively high in the region with a good correlation between temperature and precipitation. The regional ecosystems are obviously dominated by forest vegetation with lush growth in northern area where the original forest landscape remained more intact than in the south where secondary forest vegetation is dominant. In addition, W was significantly positively correlated with annual air temperature, precipitation, and evapotranspiration. A 1℃ increase in mean annual air temperature and 10 mm increase in annual precipitation and evapotranspiration could induce an increase in W by 453.71, 74.40, 219.01 kg/hm2 in standard climate-induced potential productivity, respectively. Overall, air temperature is the main factor influencing any change in W. In the future, a warm-wet climate will be beneficial for the growth of forest vegetation, whereas a cold-dry climate will be unfavorable. Climate change is expected to create a warmer-wetter climate in northern Da Hinggan Mountain region, which could increase the potential productivity. If the temperature increases (or decreases) 1-2℃, precipitation increase would be expected to increase (or decrease) 10%-20%, and the potential productivity based on climatic conditions would increase (or decrease) within a range of 10.9 to 21.7%. These results may provide a basic method for studying potential productivity based on climate change for forest vegetation at regional scales, and an important reference value for future estimations of forest carbon-sinks, implementing carbon trade in the near future, studying ecological security, and formulating ecological function planning in China's northern border. 参考文献 相似文献 引证文献

English

An investigation of the floral diversity of the littoral vegetation of Akwa-Ibom State coastline of South eastern Nigeria was carried out using quadrat and transects techniques. The results revealed three (3) vegetation types viz: coastal/shoreline, mangrove and secondary forest vegetation. Although, the most encountered ecosystem was the mangrove yet, coastal vegetation had the highest flora diversity of 100 (47%) as compared to mangrove and secondary forest with 87 (41%) and 27 (12%) species, respectively. A total of 147 taxa belonging to 134 genera and 58 families were recorded from the study area. The dominant family was Fabaceae with 17 species (29.3%), while the dominant genus was Ipomoea with 5 species (3.73%). Of these taxa, 59 occurred in more than one vegetation type while 11 were present in all the three (3) vegetation types. Phanerophytes are the dominant life form covering 36% (53 species) of the encountered species. Similarly, diversity index revealed the highest diversity of species in the coastal ecosystem with Shannon-wiener’s, Simpson’s and Margalef values of 0.99, 4.61 and 21.67, respectively. Correlation matrix and Jaccard similarity coefficient value (0.35) was high between the coastal and mangrove pairs; however, it depicts a minimal significant difference in the species composition within the three ecosystems at 0.05% probability level. Also, PCA scatter plot established less variation between the coastal and mangrove vegetation. Also, 16 economic plants were encountered during the study with uses ranging from edible fruits, spices, vegetables, root crop, and medicine, to palm wine. Factors affecting species distribution are introduction of alien species (Nypa fruticans), canalization, dredging, over exploitation of mangrove and pollution. Conservation status of these taxa according to IUCN 2014-2 showed that no endangered species was encountered during the study. However, conservation of this littoral vegetation is highly imperative in other to stabilize the ecosystem dynamics, protect the biodiversity, prevent or reduce potential effects of ecological disasters such as flooding and erosion. Key words: Littoral vegetation, flora, diversity, ecosystem, conservation.

Monitoring the Secondary Forest Succession and Land Cover/Use Changes of the Błędów Desert (Poland) Using Geospatial Analyses

Abstract The role of image classification based on multi-source, multi-temporal and multi-resolution remote sensed data is on the rise in the environmental studies due to the availability of new satellite sensors, easier access to aerial orthoimages and the automation of image analysis algorithms. The remote sensing technology provides accurate information on the spatial and temporal distribution of land use and land cover (LULC) classes. The presented study focuses on LULC change dynamics (especially secondary forest succession) that occurred between 1974 and 2010 in the Błędów Desert (an area of approx. 1210 ha; a unique refuge habitat – NATURA 2000; South Poland). The methods included: photointerpretation and on-screen digitalization of KH-9 CORONA (1974), aerial orthoimages (2009) and satellite images (LANDSAT 7 ETM+, 1999 and BlackBridge – RapidEye, 2010) and GIS spatial analyses. The results of the study have confirmed the high dynamic of the overgrowth process of the Błędów Desert by secondary forest and shrub vegetation. The bare soils covered 19.3% of the desert area in 1974, the initial vegetation and bush correspondingly 23.1% and 30.5%. In the years 2009/2010 the mentioned classes contained: the bare soils approx. 1.1%, the initial vegetation – 8.7% and bush – 15.8%. The performed classifications and GIS analyses confirmed a continuous increase in the area covered by forests, from 11.6% (KH-9) up to 24.2%, about 25 years later (LANDSAT 7) and in the following 11 years, has shown an increase up to 35.7% (RapidEye 2010).

Estimasi Pendugaan Biomassa Hutan Sekunder dan Daerah Reklamasi Menggunakan Data Citra ALOS PALSAR

Forests has an important role in stabilize CO2 concentrations in the atmosphere as a source of carbon emissions and can absorb carbon and store. It is often called a carbon sink program . To develop this program, it needs carbon stock data stored in the form of biomass using an effective technique and easy to use. This study aimed to estimate the carbon content in the area of reclamation and secondary forest resulting from mining activities through biomass allometric equation. Biomass values obtained by non-destructive method of sampling and biomass values were used to develop allometric equations using regression analysis between the biomass with a diameter of tree. The study case was located at mine concession of PT. Insani Bara Perkasa, at the border of Kutai Kertanegara and West Kutai Districts, East Kalimantan Province. The allometric biomass equations for the reclamation area: B = 0.1 x 0.41 x D2+0.62, and for secondary forests: B = 0.118 x D2,31. This biomass allometric equations can be used to predict carbon reserves stored in the secondary forest vegetation. This study also analysed the carbon stored using remote sensing. The analytical result from the ALOS PALSAR images of study area PT Insani Bara Perkasa describes that carbon sink potential is 7,83 ton/ha in reclamation area and 9,19 ton/ha in secondary forest. The estimation of carbon uptake in reclamation area of PT Insani Bara Perkasa is 8.701,205 ton/ha and 247.836,444 ton/ha in secondary forest.Those data suggest that the reclamation activity in the study area gave a little contribution to the carbon sink program yet.

Measurement of ecological niche of Quercus aliena and Q. serrata under environmental factors treatments and its meaning to ecological distribution

Quercus aliena and Q. serrata are both occur as natural vegetation alongside natural freshwater bodies of the southern Korea Peninsula. Q. serrata dominates over Q. aliena as secondary forest vegetation in the present day. In order to explain these natural distributional traits of the oak species, we conducted some experiments with oak seedlings which treated with major important environmental resources, including light, moisture and nutrients, under controlled conditions. We then measured the ecological niche breadths and overlap from 15 eco-morphological characteristics. The ecological niche breadth of Q. aliena and Q. serrata were higher in terms of the nutrient factor applied, but was lower terms of light. The niche breadth of Q. serrata was wider than that of Q. aliena in light and moisture exposure. On the other hand, the niche breadth of Q. aliena was similar with that of Q. serrata in terms of the nutrient factor applied. These results imply that Q. serrata has a broader ecological distribution in over a wider variety of light and moisture environments than that of Q. alien. Ecological niche overlap between two oak species was the widest in terms of the light treatment factor applied, and narrowest in terms of moisture. This response pattern was also verified by cluster and principle component analysis. These results suggest competitive interactions between Q. serrata and Q. aliena seedlings may be higher for light resources than moisture or nutrient resources, and that Q. serrata is more shade tolerant than Q. aliena.

Vegetation dynamics in a corridor between protected areas after slash-and-burn cultivation in south-eastern Madagascar

Slash-and-burn cultivation is a major cause of deforestation in Madagascar, and abandonment leads to the secondary vegetation dynamics, i.e. colonization by herbaceous vegetation, shrubs and trees. The study was conducted in south-eastern Madagascar in a steep transition zone along an altitudinal and a sharp precipitation gradient between a high altitude rainforest and a lowland dry tropical forest. The restoration of gaps created by abandoned fields in this narrow, winding corridor could be essential to maintain connectivity between two areas (areas 1 and 2) of Andohahela National Park. Prior to implementing restoration, baseline ecological information is needed on the reference ecosystem and vegetation resilience must be studied to identify restoration needs. This study aims to (1) assess whether cultivation practices (irrigated rice vs. cassava, maize and sweet potato) influence vegetation dynamics after abandonment; (2) study vegetation dynamics and soils over time since abandonment, and (3) compare secondary forest vegetation and soils with those of mature forest patches. Surveys of vegetation and soil were conducted in 26 secondary forest patches abandoned from 3 to >25 years (synchronic approach) and in 19 adjacent mature forest patches (controls). No relationship between age of abandonment and vegetation species richness, composition or structure was found, but clear differences were detected between secondary and mature forest patches. Secondary forests are not colonized by species from mature forests, but instead their vegetation dynamics appear to lead to the establishment of thorny thickets dominated by Mimosa delicatula, which is absent from the mature forest.

Plant Species Diversity and Endemism at Dihang Dibang Biosphere Reserve and its surroundings, Eastern Himalaya Biodiversity Hotspot

An attempt has been made to give assessment of plant species diversity of primary and secondary forest vegetation types in Dihang Dibang Biosphere Reserve (DDBR), a single biosphere reserve in Eastern Himalaya. It is excellent example of continuous unbroken forest of the Himalaya from subtropics to mountain tundra while surrounding area of southern part cover tropics. In the present study we have analyzed seventy three sample plots in different forest types and species diversity indices were calculated, Shannon-Wiener’s H¢ species richness, evenness, dominant species, dominant verses species richness, and important value index of Biosphere. The species richness in Subtropical evergreen II forest was found highest 7.21 with 350 numbers of species. Owing to the variation of microenvironment, diversity values within the same vegetation type vary between the samples from different patches. The study would be a great assistance for biodiversity conservation and planning of newly constructed DDBR and its surroundings.  Keywords - Species Diversity, Endemism, Biosphere Reserve, Eastern Himalaya