Vegetation Species Diversity Research Articles

Vegetation patterns in small boreal streams relate to ice and winter floods

Summary In‐stream and riparian vegetation are species rich, productive and dynamic. Their patterns in small boreal streams are largely driven by seasonal flow regimes. Traditionally, flow‐related processes during the growing season, particularly the spring flood, have been seen as the most important, whereas vegetation has been viewed as being dormant and ‘less affected' during winter. Riparian and in‐stream vegetation were inventoried during the summers 2011–2013 in eight reaches of northern Swedish streams. Along each reach, the ice formation was surveyed during winter by visual inspections and with permanently placed cameras. We then evaluated the potential effects of ice regimes and winter flooding on riparian and in‐stream vegetation during 3 years by relating the abundance of winter floods caused by anchor ice to the cover, composition and biomass of vegetation. We found that the numbers of winter floods were higher along reaches with anchor‐ice formation than in reaches without. We also found that species diversity of riparian vegetation was higher in the reaches with anchor ice. This resulted from a lower cover of riparian dwarf shrubs and a higher cover of graminoids and forbs along reaches with anchor ice. We also found a lower cover of in‐stream algae but a higher cover of bryophytes in anchor‐ice reaches. These patterns were consistent throughout the study period although there were interannual differences in temperature, water levels and ice cover. During our study period, we encountered an average of 20 shifts per winter between freezing and thawing, while there was an average of 10 shifts per winter during 1960–1990. This indicates a warming climate in high latitudes. Higher temperatures and more shifts between freezing and thawing may initially increase ice dynamics. However, with further increases in mean temperature, ice production should eventually decrease. Synthesis. Ice and winter floods caused by anchor ice appear to be important disturbance agents that allow less competitive species to establish along small boreal streams. If ice dynamics is reduced, the composition and production of riparian and in‐stream vegetation may be changed, with possible consequences for the entire stream ecosystem.

Vegetation dynamics of <i>Triarrhena sacchariflora</i> and <i>Carex</i> sp. community ecotone and determining factors in Lake Dongting:A case study in the Beizhouzi lake-shore

近年来,受全球变化及高强度人类活动的影响,洞庭湖湿地群落分布带不断下移,引发了人们对其湿地服务功能下降的担忧.以洞庭湖北洲子洲滩为例,采用野外样带调查和室内分析相结合的方法,对洞庭湖湿地荻-苔草群落交错带植被和环境特征进行研究,以期揭示荻-苔草群落交错带动态变化和影响其变化的关键环境因子.结果表明:土壤含水量随高程增加呈逐渐降低的趋势,土壤总碳、总氮、总磷含量和pH值在样带间差异显著,但土壤电导率和总钾含量在样带间无显著差异.各样带物种丰富度和香农指数随高程增加整体上呈先降低再增加的趋势.荻生物量随高程增加呈逐渐增加的趋势,而苔草生物量呈先增加后减少的趋势.典型相关分析表明,土壤含水量与二者生物量及群落丰富度、多样性间具有很好的相关性,表明土壤含水量是调控该群落交错带植被动态变化的关键环境因子.;In recent years, the vegetation distribution decreased significantly in Lake Dongting due to global change and intensive human disturbance, and has induced significant concerning about the decrement of service functions. In order to reveal the vegetation dynamics and its dominant influencing factors of Triarrhena sacchariflora and Carex sp.community ecotone, we took Beizhouzi lake-shore as an example, and investigated the vegetation characteristics and soil environmental characteristics in the ecotone of T. sacchariflora and Carex sp.community in the Lake Dongting based on belt sampling method and indoor measurement. The results showed that: soil moisture decreased significantly along with increment of elevation. Total carbon, total nitrogen, total phosphorus and pH had significant difference between these belts, while conductivity and total potassium displayed similar patterns. Vegetation species richness and diversity index decreased firstly and then increased along with elevation. Biomass of T. sacchariflora increased significantly along with elevation, while biomass of Carex sp.community exhibited increase firstly, followed by decrease with elevation. Canonical correlation analysis showed that soil moisture was significantly correlated with both biomass accumulation of T. sacchariflora and Carex sp., and vegetation species richness and diversity, indicating that soil moisture is the key dominant factor influencing vegetation dynamics in this ecotone.

Variations in soil properties, species composition, diversity and biomass of herbaceous species due to ruminant dung residue in a seasonally dry tropical environment of India

Ruminants directly or indirectly influence nutrient cycling and vegetation structure in grassland ecosystems. We assessed the impact of natural cattle dung deposition on soil attributes and the resulting effects on species composition, species diversity and biomass of herbaceous vegetation in a natural grassland in the seasonally dry tropical environment of Banaras Hindu University, India. For this 72 plots of 1 × 1 m [12 locations × 2 treatments (dung residue and control) × 3 replicates] were selected in January 2013 and soil and vegetation samples collected. A total of 74 species belonging to 66 genera and 25 families were recorded. Principal Component Analysis (PCA) ordination revealed that the dung residue (DP) and control (CP) plots were distinctly different in terms of soil attributes and species composition. The k -dominance plot showed greater species diversity in DPs than CPs, with higher soil nutrients and moisture and lower soil pH in DPs than CPs. Similarly, DPs showed more herbaceous species and greater biomass than CPs. This trend can be explained by the positive responses of forbs, erect plants, annuals, large-statured, non-native and non-leguminous species to dung residue, while increased biomass can be partly due to cattle preferentially not grazing areas adjacent to a dung pat. Overall, the study showed that deposition of dung during grazing by cattle stimulates growth of pasture species and increases species diversity. Therefore cattle dung could be used as a sustainable alternative to chemical fertilizers to manage soil pH, species composition and diversity, and forage production in the seasonally dry tropical grasslands of India, which are nutrient- and moisture-limited. Keywords: Animal manure, herbaceous vegetation, plant functional attributes, soil pH, species change. DOI: 10.17138/TGFT(3)112-128

Оценка видового разнообразия растительности на основе интегрального статистического подхода в условиях неоднородных данных (на примере заповедника «Калужские засеки»)

Оценка видового разнообразия растительности на основе интегрального статистического подхода в условиях неоднородных данных (на примере заповедника «Калужские засеки»)

Vegetation structure, floristic composition and species diversity of woody plant communities in sub-tropical Kandi Siwaliks of Jammu, J & K, India

The study was conducted on sub-tropical forest of districts Jammu and Samba of Jammu province of Jammu and Kashmir state, India with the objective of determining floristic composition, species diversity and structure of woody vegetation in drier Kandi Siwaliks. The forests of Kandi belt represent typical subtropical vegetation with distinct vertical zonation of three forest types i.e., Northern dry mixed deciduous forests (5B/C2), Himalayan subtropical scrub (9/C1/DSI) and Himalayan subtropical Pine forest (9/C1a) in an altitudinal range of 300 m asl to 990 m asl. The community analysis was performed using stratified random sampling involving 0.01 % of the total area for each community. Accordingly, 750 quadrats of 400 m 2 and 100 m 2 were laid for trees and shrubs respectively after attaining their species area curve. Various phytosociological parameters and diversity indices have been used to reveal the community structure, species richness, diversity and evenness for the phanerophytes in different forest types. A total of 112 species comprising 65 trees and 47 shrubs belonging to 92 genera and 48 families were recorded from the forest. The vegetation analysis revealed the dominance of Mallotus philippensis (SIV %, 6.4), Acacia modesta (10.44 %) and Pinus roxburghii (24.27%) as over storey elements in northern dry mixed deciduous forests, Himalayan subtropical scrub and Himalayan subtropical Pine forest respectively. The northern dry mixed deciduous forests occupying 27.3 % of the study area revealed maximum species richness and diversity as indicated by the higher values obtained for Shannon-Wienner’s index and Simpson’s index of dominance. Most of the forest landscapes are influenced by human disturbances and thus necessitates the need for immediate conservation action plan to ensure sustainable utilization and better management of forest.

Species richness, diversity and density of understory vegetation along disturbance gradients in the Himalayan conifer forest

We investigated whether species richness, diversity and density of understory herbaceous plants differed along logging (gap) and grazing (primarily by cattle) disturbance gradients, and sought to identify drivers of richness, diversity and density of understory vegetation of logged sites. A factorial experiment was conducted in the mixed conifer forest of Gidakom in Western Bhutan. Levels of the logging treatment included small (0.15 – 0.24 ha), medium (0.25 – 0.35 ha) and large (0.36 – 1.31 ha) gaps. The grazing treatment included grazed (primarily by cattle) and ungrazed (where herbivores were excluded by a fence) plots nested within each gap. Data were collected from 12 gaps (4 replicates at each level of logging) using the point intercept method. Shannon Weaver Diversity and Margalef’s indices were used to estimate species diversity and describe species richness, respectively. Soil samples were analyzed for pH and nutrients. The interaction effect of logging and grazing was significant (p≤0.001) only on species diversity. Relative to ungrazed areas, species diversity was significantly higher (0.01≤p≤0.05) in medium grazed gaps. Under grazed conditions, soil P was negatively correlated with gap size and species diversity. While species diversity was positively correlated (0.01≤p≤0.05) with soil N in grazed plots species richness was positively correlated (0.001≤p≤0.01) with soil N in ungrazed plots. Relative density of Yushania microphylla and Carex nubigena were higher under ungrazed conditions. Our study suggests that the combined effect of cattle grazing and logging results in higher species diversity of understory vegetation in medium and grazed gaps in mixed conifer forests of Bhutan,whereas increase or decrease in relative density of major species is determined primarily by the independent effects of grazing and logging. From management perspective, forest managers must refrain from creating large gaps to avoid loss of nutrients (mainly P and N), which may eventually affect tree regeneration. Managers intending to maintain understory vegetation diversity must consider the combined effects of grazing and logging, ensuring low to moderate grazing pressure.

English

The present investigation was carried out on distribution of soil types, vegetation and tree species diversity in Eastern Ghats of Srikakulam District, Andhra Pradesh, India. The inventory of tree species was done in 40 different forest areas of Srikakulam district. All the sample plots are tropical and moist thorny forest and dry thorny scrub forests of Srikakulam district. The soils of the study area are compressed red soils, loamy soils, sandy loams, with varying proportions of sand and clay and it constitute 96% of the total area; red sandy soil is the common type. Tree species richness varied according to the disturbance gradient in the different stands, a total of 4744 individuals, belonging to 129 species, 96 genera among 46 families from 40 line transects were recorded in the study area. Species richness ranging from 47 to 9 in a transect was recorded in the present study. Highest species richness of sizes 47 for 65-N/14 (SW-3, 65N-14 NW-3) was seen at Haddubanghi and lowest diversity 9 was seen at Korasanda 74-B/1(SE-1). Key words: Soil types, vegetation, tree species diversity, Srikakulam district.

Does species diversity affect the function of residential greening in the Yangtze River Delta

The purpose of this study was to investigate whether high plant species diversity could increase the landscape and ecological function of residential greening in a random selection of nine cities, Ningbo, Shaoxing, Jiaxing, Hangzhou, Nanjing, Zhenjiang, Changzhou, Wuxi and Suzhou, in the Yangtze River delta. A quantitative evaluation system was used to evaluate the landscape and ecological function of green space. The relationship between landscape/ecological function and species diversity was analyzed by linear regression. The results indicated that the average Simpson’s index of the 27 surveyed residential green spaces was 8.74 ± 0.60, while the score for landscape effect/ecological function was 6.25 ± 1.42 and 2.70 ± 0.90 respectively. There was a significant correlation between vegetation species diversity and landscape function, and further investigation indicated that more tree species could have a greater effect than more shrubs and herbs. In contrast, there was no significant correlation between vegetation species diversity and ecological function. Thus, the results suggested that high plant species diversity in the majority of residential areas would only improve landscape, and not ecological, function.

Vegetation composition of old extensive green roofs (from 1980s Germany)

Since their development in the late 1970s in Germany, extensive green roofs (EGR) have become increasingly popular as mitigation tools for urban environmental issues around the world. EGRs are planted with select species, which ensure consistent cover and performance over time. This research presented herein is part of a systematic re-evaluation of EGR technology since the German industry began. Given the opportunity to access a small sample of old EGRs installed over 20 years ago in south-west Germany, this research surveyed the vegetation and substrate with an interest in describing these parameters with time-through-space substitution. Similar to previous studies, this preliminary work found correlations between roof age with vegetation (cover abundance and species diversity) and substrate properties (e.g., depth, organic content, pH, and nutrients). Roof age had positive relationship with soil organic content (Corg), and negative relationships with substrate depth and soil pH. These soil variables are inter-related, as shallow acidic substrates create unfavourable conditions for decomposition and thereby the accumulation of duff. Substrate variables correlated with EGR vegetation, suggesting a trend of simplified species composition over time. Indeed, Corg had a negative relationship with cover and species diversity of most life forms; only Sedum species had positive associations with Corg. Considering the dynamics associated with shallow mineral substrates, and the greater floristic diversity of younger roofs, simple Sedum-based vegetation may represent a steady state for conventional EGRs.

Relationship between species composition and homegarden size in Odeda lga of Ogun State Nigeria

Studies on correlation between species composition and homegarden size in thirty (30) house gardens in Odeda Local Government Area of Ogun State, Southwestern Nigeria was conducted. Plants grown and maintained by household members and the diversity of vegetal species and their uses were assessed using semi-structured questionnaire and structured interview. A total of 120 different plant species belonging to 50 Families were documented. From the data, Euphorbiaceae, Solanaceae, Rutaceae, Malvaceae, Caesalpiniaceae, Poaceae and Apocynaceae (in order of decreasing number of species) were the most frequent Families. Taxa such as Musa species, Vernonia amygdalina, Citrus species, Psidium guajava and Terminalia catappa were found to be the common food/medicinal plants as evidenced by their densities in the study sites. The household members cited most of the plants as food; others as medicinal and ornamentals. Miscellaneous uses include cosmetics, ceremonial and scouring. Homegarden products serve alimentary purposes and represent promising base materials for poverty alleviation and may also help to augment “fresh” food nutrient intake. Pearson Correlation analyses indicated no statistically significant association between species composition and homegarden size (Simple correlation=0.289, P=0.122). Species composition and homegarden structures as well as plant uses are discussed. Key words: Homegarden, Odeda, Southwestern Nigeria, Species composition

广东中西部桉树人工林植物多样性与林龄和土壤因子的关系

Commercial eucalypt plantation forest has become a unique ecosystem in the wide-range of the tropical and subtropical regions in China. In this unique ecosystem,the under-story vegetation is identified as an important concern for biodiversity conservation and sustainable management for a long run. In the past decade,efforts have been made to understand the species composition and diversity of the vegetation associated with eucalypt and other fast-growing tree plantations. However,much work is still needed to cumulate the knowledge and to provide an overall coverage of this topic and the relevant issues. In the present study,we investigated the under-story vegetation community of short-rotation eucalypt plantations in Gaoyao,Guangdong to compare species composition and diversity at three different age classes,and to study the relationship of species distribution and diversity with soil factors by using canonical correspondence analysis( CCA) and correlation analysis. The result showed that difference in species number significant to a certain extent was observed among three stand age classes when the number of the sampling plots was equal or more than 9,and a size of 24 sampling plots per age class was sufficient for analyzing the species composition. Totally,there appeared 136 vegetationspecies belonging to 54 families and 107 genera in the stand plots sampled,among which there were 80 tree and shrub species,36 herbs and 20 lianas. Although tree and shrub species were rich in number, two herbaceous species( Dicranopteris dichotoma( Thunb.) Bernh. and Miscanthus sinensis Anderss.) were always dominant in abundance and coverage over the stand plots studied. Species number did not significantly differ among stand age classes,but was consistently lower in stands at 1—2 years old than at other two age classes,attributed to the abrupt change and fast restoration of vegetation during and after the establishment stage of stands,respectively. The diversity measures( Simpson index,Shannon index and richness) of the vegetation species were highest for eucalypt stands at 3—4 years old. The ordination analysis indicated that the under-story vegetation species was closely related to the first two ordinations of CCA,with correlation coefficients of 0. 856 and 0. 943,respectively,and the cumulated variance proportion of 51. 1%. While the first ordination axis was obviously controlled by the organic matter and total phosphorus,the second ordination axis was mainly contributed by the total potassium and soil bulk density. The species distribution pattern was significantly influenced by these soil factors,and also related to the pH value in a way. In contrast,the vegetation species diversity was consistently shaped by the total nitrogen and pH value,increasing with the total nitrogen and pH value from low to neutral level. Fertile forest soils with neutral pH value favored to restore or maintain the vegetation diversity associated with short-rotation and intensively managed plantations. We also discussed the negative effects on under-story vegetation of developing shortrotation plantation in large scale and intensive silvicultural operations such as forest road network building and maintenance,burning,site clearance and preparation,weeding,clear-cut and log transportation,etc. Eucalypt cultivation reduces species diversity through changed forest environments and soil properties such as physical structure,moisture and nutrient.

Succession in soil and vegetation caused by coastal embankment in southern Laizhou Bay, China—Flourish or degradation?

Coastal wetland degradation and loss caused by intensive human activities, such as land reclamation and embankment, is a serious environmental problem. In this paper, we studied the succession of soil and vegetation in a coastal wetland dominated by Chinese tamarisk (Tamarix chinensis) community after the construction of a seawall. When the intertidal wetland became supratidal wetland, soil salinity firstly decreased and the gradient from sea to land became weaker. Next, the area of vegetation and plant species diversity increased, and the phenomenon of plant zonation disappeared. We reasoned that the rooted cause of soil and vegetation succession was the change in hydrological environment. Moreover, a Drivers-Pressures-State-Impacts-Response (DPSIR) model was used to analyze the relationship between human activities and coastal wetland. Using this model, we presented the potential problems that might arise in this wetland and predicted that vegetation flourishing was only a short term phenomenon but wetland degradation was the final consequences due to excessive exploitation of groundwater. At last, we proposed a few of operable measures as responses to these potential problems from the perspective of coastal management.

Shoreline Vegetation in the Danjiangkou Reservoir: Characteristics, Related Factors, and Differences with Adjacent Riverine Wetlands

Reservoirs created by damming rivers and inundating terrestrial areas can have serious effects on ecosystem structure and functions of riverine wetlands. Here, we tested the hypothesis that reservoir shorelines had similar vegetation characteristics to adjacent riverine wetlands due to propagule dispersal and examined whether vegetation distribution in reservoir shorelines was related to topographic factors. We investigated 146, 44, and 67 plots in shorelines of the Danjiangkou Reservoir, upstream and downstream wetlands, and tributary wetlands, respectively. Results revealed that reservoir shorelines had a similarity of 45% to riverine wetlands in species composition. Two‐way indicator species analysis demonstrated that communities in reservoir shorelines were dominated by mesophyte species such as Cynodon dactylon and Abutilon theophrasti, while communities in riverine wetlands were largely dominated by hygrophyte species including Paspalum paspaloides, Alternanthera philoxeroides, and Polygonum hydropiper. Moreover, species diversity and percentage of perennial species in reservoir shorelines were lower than those in riverine wetlands. Canonical correspondence analysis indicated that topographic factors including landform, slope, and distance to water were important factors regulating species and community distribution in reservoir shorelines. Landform and slope also strongly influenced the species diversity of shoreline vegetation. Results from this study may contribute to a better understanding of shoreline vegetation in large subtropical reservoirs and provide information for future re‐vegetation in the Danjiangkou Reservoir after dam heightening.

Comparison of short term low, moderate, and high severity fire impacts to aquatic and terrestrial ecosystem components of a southern USA mixed pine/hardwood forest

Historically fire was an important natural disturbance shaping the structure and composition of pine-dominated forests in the southern United States. Longstanding fire suppression policies have resulted in structural and compositional changes, notably accumulation of heavy fuel loads and reduction in vegetation species diversity. Primary goals of forest management through prescribed burning include fuel load reduction and mimicking ecosystem impacts of historically natural wildfires. In addition to the influences of fire frequency and season, the influence of fire severity on ecosystem responses is currently of interest. In this study we sought to quantify the impacts of low, moderate, and high severity fires, and their interaction with prior forest management practices, to several aquatic and terrestrial ecosystem components of a southern U.S. mixed pine/hardwood forest using a before–after, control-impact (BACI) approach. The ecosystem components we assessed were water quality, community composition of aquatic arthropods (wildfire impacts only), forest structure characteristics, community composition of understory vegetation, and community composition of ground-dwelling arthropods. We found that increasing fire severity increased aquatic nutrient levels and productivity, but the magnitude of effects increased with severity. Low and moderate severity fires had weak effects on forest structure characteristics, community composition of understory vegetation, and community composition of ground-dwelling arthropods in the initial years following burns. In contrast, high severity fires dramatically reduced fine and large fuel loads, increased diversity of understory vegetation, and influenced community composition of ground-dwelling arthropods. Further, wildfire severity was reduced in areas with a prior moderate severity prescribed burn, but not in areas with a prior low severity prescribed burn. Our results provide quantitative evidence for the role of fire severity as a primary factor influencing responses of ecosystems to fire, and indicate that forest management practices influence the impact of high severity fires on ecosystems.

Soils of technogenic landscapes in the Far East: The Luchegorsk and Pavlovsk coal strip mines

Soils and vegetation developed on dump rock of coal strip mines located in different hydrothermic provinces of the Primorskii region have been studied. The formation of phytocenoses on dump rocks proceeds in several consecutive stages, during which the species diversity of vegetation and the total pool of vegetative organic matter regularly increase. This results in a progressive development of humus accumulation. In turn, it leads to the morphological, chemical, and physicochemical differentiation of the soil profiles. General and specific features of pedogenesis in the studied areas are described.

Structure and woody species diversity of the Dasylirion cedrosanum (Nolinaceae) rosette scrub of central and southern Coahuila state, Mexico

The most prominent vegetation type in the state of Coahuila, in northern Mexico, is Chihuahuan Desert Scrub. This plant formation encompasses the little known Dasylirion cedrosanum (sotol) rosette scrub, a community that extends over more than one fourth of Coahuila and whose most distinctive species is subjected to intense extraction from its native communities for a variety of purposes. Based on a highly replicated sampling procedure that included 131 plots located in the state’s central and southern portions, we analyzed vegetation structure, floristics, and species diversity of this plant community. A cluster analysis allowed us to differentiate five variants (associations) of the Dasylirion cedrosanum rosette scrub, which together host a richness of 97 species of vascular plants distributed in 61 genera and 28 families. These communities occurred across an elevational range of 850-2,550 m a.s.l. Dasylirion cedrosanum density varied between 193 and 705 ind./ha, with the highest value occurring in the Quercus intricata - Dasylirion cedrosanum association. Other prominent species in these scrublands were Agave lecheguilla and Euphorbia antisyphilitica. The Agave lecheguilla-Dasylirion cedrosanum association was the most broadly distributed and it hosted the highest richness species, while the largest Shannon diversity index value was recorded for the Dasylirion cedrosanum - Viguiera greggii association. The effects of human utilization of this species on the structure of those plant communities where it occurs are largely unknown; further studies are needed to better understand its dynamics and to be able to suggest more adequate regulations for its commercial harvesting.

Species diversity and forage value of herbage in a neglected coconut land proposed for livestock integration

The proposed coconut land is situated in the southern province. belongs to the land suitability class S4which is moderately suitable for coconut. Therefore, managing coconut as rnonoculture is unprofitableand steps have been taken to optimize the land use through livestock integration. Therefore, objectiveof this study was to investigate the species diversity and forage value of understory vegetation in thecoconut land before introducing cattle. Stratified quadrate sampling technique was adopted and 4samples each from 6 paddocks (approx 0.4 ha) were randomly taken. Each stratum contained morethan 80% of edible species while the non edible species found in all strata were common uplandweeds Axonopus affinus (carpet grass), Axonopus compressus (narrow carpet grass) andDesmodium trifolium were dominant prostate grass and legume species found in 0-5 em strataabove ground level. In addition to above species Pueraria phasioloides (Centro) was found to bedominant in 5-15 em strata. Crysopogen ariculatus and Pueraria phasioloides were dominant in15-25 cm strata while Seteria anceps (fox tail grass) found to be dominant above 25 em height. Thecommon non-edible species found in the lower two strata's were Urena lobota, Hemidcsmus indicumand Ocimum tenuiflorum while Lantana camara and Ocimum tenuiflorum were dominant in uppertwo strata's. The dry matter (DM) and crude protein (CP) content of edible herbage increased frombottom to top layers ranged from 390 gkg' to 480 gkg' and 75 gkg' to 100 gkg' respectively.The results of this study reveal that the species diversity and forage value are in an acceptablestandard to initiate cattle grazing. However, crop and cattle management strategies are important inorder to improve coconut and livestock performance.

Effects of water conveyance embankments on riparian forest communities at the middle reaches of the Tarim River, Northwest China

ABSTRACTEcohydrological research focuses on the relationship between changes in the hydrological conditions and the response of plant communities to those changes. To save the degraded riparian forests at the lower reaches of the Tarim River, water conveyance embankments (whose goal is to prevent water from overflowing the riverbanks) were constructed mid‐stream in order to guide the watercourse down to the river's destination. To investigate and evaluate the influence of these embankments on the Tarim River's riparian forest communities, we prepared three monitoring sections (five others were added later) that included six monitoring wells, six vegetation sample plots and six soil profiles at each section. From 2001 to 2007, data on groundwater depth, vegetation coverage, species diversity, total dissolved solids and concentrations of ions were collected and analysed. The results indicate that groundwater depths gradually increased, total dissolved solids and major ions in groundwater sharply increased and vegetation coverage and species diversity declined. Moreover, at the start of our investigation, the hydrological connection extended more than 1000 m from the embankments; by 2007, however, the region beyond 800 m had become a water and salinity discharging area. On the basis of these findings, the removal of the embankments should be urgently considered to protect the riparian forest ecosystems. Copyright © 2013 John Wiley & Sons, Ltd.

Check dam influence on vegetation species diversity in mountain torrents of the Mediterranean environment

ABSTRACTPrevious research has developed a method to assess the impact of check dams on riparian vegetation and related river bed sediment size with vegetation coverage and development. On the basis of this knowledge, this paper aims to investigate the effects on riparian species diversity induced by 32 check dams in four torrent headwaters of Southern Italy. Species richness and composition of riparian vegetation in the active channel were surveyed upstream and downstream of each check dam and in intermediate (less disturbed) sites. Furthermore, links between hydromorphological processes and vegetation diversity were analysed.The identified differences in species diversity seem to be related to the morphological adjustments of the channel after the installation of check dams. These fluvial morphological adjustments introduced variations to the flood depth and frequency of the riparian areas creating new riparian conditions. Higher species richness and evenness were observed upstream of check dams, where alien species prevail over native ones in new habitats on the sedimentation wedge behind the dam. Conversely, downstream of check dams, where the boundary of the inundated area moves down towards the thalweg (due to incision processes after check dam installation), riparian vegetation tends to assume a terrestrial character, losing some herbaceous species of the riparian environment.This research confirms that the discontinuity in the fluvial environment caused by check dams induces morphological adjustments that can be translated in new riparian conditions for the establishment of vegetation, affecting the ecological aspects and species diversity of riparian habitats. Copyright © 2013 John Wiley & Sons, Ltd.

Evaluating Ecological Restoration Success: A Review of the Literature

AbstractAssessing the success of ecological restoration projects is critical to justify the use of restoration in natural resource management and to improve best practice. Although there are extensive discussions surrounding the characteristics that define and measure successful restoration, monitoring or evaluation of projects in practice is widely thought to have lagged behind. We conducted a literature review to determine trends in evaluations of restoration projects and identify key knowledge gaps that need to be addressed. We searched the Web of Knowledge plus two additional restoration journals not found in the database for empirical papers that assessed restoration projects post‐implementation. We quantified the extent that key attributes of success, including ecological (vegetation structure, species diversity and abundance, and ecosystem functioning) and socioeconomic, were addressed by these papers along with trends in publication and restoration characteristics. Encouragingly, we found the number of empirical evaluations has grown substantially in recent years. The increased age of restoration projects and number of papers that assessed ecological functions since previous reviews of the literature is also a positive development. Research is still heavily skewed toward United States and Australia, however, and identifying an appropriate reference site needs further investigation. Of particular concern is the dearth of papers identified in the literature search that included any measure of socioeconomic attributes. Focusing future empirical research on quantifying ecosystem services and other socioeconomic outcomes is essential for understanding the full benefits and costs of ecological restoration and to support its use in natural resource management.