Composition and ecology of the Quercus coccifera L. communities along the eastern Adriatic coast (NE Mediterranean)

The aim of this study is to classify and describe all plant communities with Quercus coccifera covering the entire eastern Adriatic coast and islands from north Croatia to south Albania, and to relate their species composition, chorotypes and life forms to environmental factors using Pignatti ecological indicator values. From total 70 phytosociological relevés, we identified and described four floristically and ecologically distinctive vegetation communities (two new proposed subassociations, one association and stand each) using TWINSPAN and the Braun-Blanquet classification scheme. In Croatia and Montenegro, Q. coccifera is forming macchia within the Fraxino orni–Quercetum cocciferae pistacietosum lentisci. Quercus coccifera occurs only sparsely in south Croatia as a shrubland within Fraxino orni–Quercetum cocciferae nerietosum oleandri subassociation or macchia within the Erico arboreae–Arbutetum unedonis association. Despite the difference in biogeographic position and bioclimates, low shrubby Albanian Q. coccifera stands are more closely related to the Q. coccifera communities from the western Mediterranean. Eastern Adriatic communities appear exclusively within the Querceta ilicis vegetation zone and spread within the meso-Mediterranean belt. They nevertheless are an important part of the region's natural heritage and management plans must ensure that all forms of land are used in a sustainable way.     

Vegetation patterns generated by a wind driven sand-vegetation system in arid and semi-arid areas

Wind has been proposed as a driving factor in determining vegetation patterns, but there are few dynamic models that include both vegetation and wind. In this paper, we present a dynamic model to investigate how a vegetation pattern is generated and affected by wind. In the model, the effects of prevailing wind and non-prevailing wind on sand and vegetation are modeled respectively as advection terms and diffusion terms. With these considerations and proper parameter values that satisfy Turing bifurcation conditions, labyrinth and banded vegetation patterns are obtained in two situations of wind. By changing wind transportation capacity, we simulate the adaptation process from one vegetation pattern to another. With environmental changes of large amplitude, the width of vegetation bands varies while the wavelength can increase but does not decrease in our simulation. Then we describe the difference between simulated patterns and real patterns. And in the discussion, we explain the mechanism that forming patterns and the consistency of this research with other studies.     

Climate and vegetation in China II. Distribution of main vegetation types and thermal climate

The authors examined relationships between Kira's warmth index (WI) and four other important thermal indices: the sums of daily mean temperatures above 5°C and 10°C, Thornthwaite's potential evapotranspiration (PE) and Holdridge's annual biotemperature. The thermal records of 671 meteorological stations evenly located all over China were used to make these comparisons. Close correlations were found within the four relationships, and accordingly WI was used to analyse the thermal distributions of the main vegetation types. Vegetation types around the 671 stations were read from a vegetation map with a scale of 1/4000000. Vegetation types at 269 stations corresponded to the natural or seminatural vegetation, and 29 vegetation types were distinguished by arranging the 269 data into the same or similar types. The geographical distribution of these 29 types and the corresponding main climatic features were described. The relations between WI and distribution of these vegetation types were discussed in detail. As a result, WI values (°C month) corresponding to the vegetation zones could be summarized as follows: (1) arctic or alpine vegetation zone: 0–15; (2) boreal or subalpine vegetation zone: 15-(50–55); (3) cool-temperate vegetation zone: (50–55)–(80–90); (4) warm-temperate vegetation zone: (80–90)–(170–180). These values almost coincided with Kira's values. Chinese postgraduate student in Japan sent by the Chinese Government.     

青藏高原地区气候图解数据集

气候图解可以直观反映气象台站基本信息和气温、降水等气象数据,是研究植被与气候关系的有效方式。为便于了解青藏高原不同植被区域气候特征,进一步认识青藏高原植被与气候关系,该文基于1951–1980年与1981–2010年青藏高原地区国家地面气象台站基本信息和各30年平均观测数据,依据《中国植被》所述标准制作每个气象台站的气候图解。论文提供了青藏高原地区主要台站气候图解集,包括两个30年时间段共计205幅图解。研究表明:(1)青藏高原地区气温和降水总体水平偏低,前后30年年平均气温和年降水量整体呈上升趋势;(2)青藏高原地区各气象台站记录值随植被区域不同表现出较大差异。虽然青藏高原西部地区的气象台站数量很少,但该数据集仍涵盖了高原面上的不同植被地带,可有效运用于高原植被与气候关系研究,为展示高原气候环境等提供便利。     

Relationship between hydrology and vegetation change from Sphagnum lawns to vascular plant Sasa communities

We examined the relationship between fluctuation patterns of groundwater levels (WL) and the distribution dynamics of the vascular plant Sasa palmata, in Sarobetsu Mire, northern Japan. WLs were recorded at 30 stations: 11 Sphagnum lawns, which is the original vegetation type in the area, nine Sasa communities, and ten boundary stations between those two areas. The ten boundary stations were composed of five vegetation change sites and five stable sites, categorized using maps of Sasa distribution in 1977 and 2000. The results showed that Sphagnum lawns and Sasa communities significantly differed in the average, minimum, and fluctuation range of WLs, and increases in WL after rain events. The differences between change sites and stable sites were not significant in the average WL, but were significant in the minimum and fluctuation ranges of WL and the increase in WL after rain events. These results indicate that the distribution dynamics of Sasa communities would be regulated by groundwater flow that was affected by drainage and inflow condition rather than merely groundwater drawdown as suggested in previous studies. The WL regimes at two Sphagnum lawns were similar to those at change sites, suggesting that Sasa may expand into these two stations more readily than the other Sphagnum lawn stations.     

Fish assemblage structure in relation to macrophytes and filamentous epiphytes in shallow non-tidal rocky- and soft-bottom habitats

Synopsis The fish assemblage in nineteen shallow water (0–3 m) areas on the Swedish west coast, including an estuarine zone, was assessed during spring and autumn 1989 and autumn 1990, using semi-quantitative survey nets. Samples of macrovegetation were collected concurrently for estimates of species composition and biomass. Nine stations had rocky-bottom substrata and ten had soft-bottom substrata all characterized by high coverage of macrovegetation and variously overgrown with epiphytic filamentous algae. Fish assemblage structures were compared and related to vegetation biomass, substrata and estuarine influences. At rocky-bottom stations total fish biomass was positively correlated with total vegetation biomass and negatively correlated with the proportion of filamentous algae during autumn samplings. In soft-bottom habitats variation in vegetation was small between stations, and no correlation existed between vegetation biomass and fish biomass. However, the number of fish species in soft-bottom habitats decreased significantly with increasing dominance of filamentous algae. The component species of the fish assemblage varied in their relation to the vegetation biomass and structure suggesting differences in degree of association with vegetation at the species level. Multivariate analysis based on fish species composition and on vegetation assemblages at the individual stations, yielded two major groups in accordance with division of the substrate into rocky- and soft-bottom habitats. Vegetation biomass superimposed on the fish assemblage ordination indicated a relationship between vegetation biomass and fish assemblage structure. Location of stations, in relation to the estuary was reflected in subgroups formed in the fish assemblage based cluster and ordination, suggesting a substantial estuarine influence on the fish assemblages. Thus, substrate type, vegetation biomass and structure, and estuarine influence are all potential structuring factors for the fish assemblages. In our study, vegetation structure seems to be of major importance and changes such as increased dominance of filamentous algae, like that observed in coastal areas in Sweden, might cause significant changes in fish assemblage structure.     

Effects of land-use changes on benthic macroinvertebrate assemblages in the tropical Umfurudzi River,Zimbabwe

The responses of benthic macroinvertebrates to land-use-induced changes in water quality and habitat because of contrasting land-use types along the Umfurudzi River, Zimbabwe, were investigated in 2013. Five stations in a communal area upstream of Umfurudzi National Park, four on the edge of the park and six in the park were sampled monthly from April to July 2013 for physico-chemical variables and aquatic macroinvertebrates. Phosphates and siltation levels were significantly higher at stations in the communal area, compared to those in the park. Vegetation cover and conductivity were significantly higher at stations in the park compared to those in the communal area. Recovery of macroinvertebrate communities along a disturbance gradient from the highly disturbed, silted, low percentage vegetation cover communal area stations through the semi-disturbed park edge area to the less disturbed, less silted, high percentage vegetation cover stations in the park was demonstrated. Consequently, the management of tropical catchments should include practices that minimise loss of riparian vegetation and that guard against siltation of aquatic systems. The study also demonstrates the capacity of macroinvertebrates to act as indicators of these disturbances.     

Formation of banded vegetation patterns resulted from interactions between sediment deposition and vegetation growth

This research investigates the formation of banded vegetation patterns on hillslopes affected by interactions between sediment deposition and vegetation growth. The following two perspectives in the formation of these patterns are taken into consideration: (a) increased sediment deposition from plant interception, and (b) reduced plant biomass caused by sediment accumulation. A spatial model is proposed to describe how the interactions between sediment deposition and vegetation growth promote self-organization of banded vegetation patterns. Based on theoretical and numerical analyses of the proposed spatial model, vegetation bands can result from a Turing instability mechanism. The banded vegetation patterns obtained in this research resemble patterns reported in the literature. Moreover, measured by sediment dynamics, the variation of hillslope landform can be described. The model predicts how treads on hillslopes evolve with the banded patterns. Thus, we provide a quantitative interpretation for coevolution of vegetation patterns and landforms under effects of sediment redistribution.     

Factors influencing the distribution of nests of the Argentine ant Linepithema humile Mayr (hymenoptera: formicidae), in a foothills ecosystem of the central zone of Chile

The purpose of this research was to demonstrate the dependant relationship between the Argentine ant Linepithema humile Mayr, plant coverage, and human settlements. A method was designed in order to sample the presence of the Argentine ant and other ant species that may had influenced L. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. Eight sample stations were established. Four of these stations were found on a dwelling home and the other four were found on similar areas, but far from human settlements. Three transects were established from the center of each sampling station (Tt1, shrublike vegetation, Tt2, herblike vegetation and Tt3, no vegetation). Transects were compound by 10 m side quadrants. A negative correlation was found between nest number of L. humile and human settlement distance, therefore nests were not found at distances higher than 80 m, in all studied areas. There was a positive and significant correlation between nest number of L. humile and plant coverage percentage, regardless the type of vegetation found. The same trend was found for other ant species studied in the area. Finally, it was proved that the distribution of L. humile nests is not influenced by other ant species.     

中国东部温带植被生长季节的空间外推估计

利用地面植物物候和遥感归一化差值植被指数（NDVI）数据,以及一种物候-遥感外推方法,实现植被生长季节从少数站点到较多站点的空间外推。结果表明：（1）在1982～1993年期间,中国东部温带地区植被生长季节多年平均起讫日期的空间格局与春季和秋季平均气温的空间格局相关显著;（2）在不同纬度带和整个研究区域,植被生长季节结束日期呈显著推迟的趋势,而开始日期则呈不显著提前的趋势,这与欧洲和北美地区植被生长季节开始日期显著提前而结束日期不显著推迟的变化趋势完全不同;（3）北部纬度带的植被生长季节平均每年延长1．4～3．6d,全区的植被生长季节平均每年延长1．4d,与同期北半球和欧亚大陆植被生长季节延长的趋势数值相近;（4）植被生长季节结束日期的显著推迟与晚春至夏季的区域性降温有关,而植被生长季节开始日期的不显著提前则与晚冬至春季气温趋势的不稳定变化有关;（5）在年际变化方面,植被生长季节开始和结束日期分别与2～4月份平均气温和5～6月份平均气温呈负相关关系。     

Determining the growing season of land vegetation on the basis of plant phenology and satellite data in Northern China

The objectives of this study are to explore the relationships between plant phenology and satellite-sensor-derived measures of greenness, and to advance a new procedure for determining the growing season of land vegetation at the regional scale. Three phenological stations were selected as sample sites to represent different climatic zones and vegetation types in northern China. The mixed data set consists of occurrence dates of all observed phenophases for 50–70 kinds of trees and shrubs from 1983 to 1988. Using these data, we calculated the cumulative frequency of phenophases in every 5-day period (pentad) throughout each year, and also drew the cumulative frequency distribution curve for all station-years, in order to reveal the typical seasonal characteristics of these plant communities. The growing season was set as the time interval between 5% and 95% of the phenological cumulative frequency. Average lengths of the growing season varied between 188 days in the northern, to 259 days in the southern part of the research region. The beginning and end dates of the surface growing season were then applied each year as time thresholds, to determine the corresponding 10-day peak greenness values from normalized difference vegetation index curves for 8-km² pixels overlying the phenological stations. Our results show that, at the beginning of the growing season, the largest average greenness value occurs in the southern part, then in the northern, and finally the middle part of the research region. In contrast, at the end of the growing season, the largest average greenness value is measured in the northern part, next in the middle and lastly the southern part of the research region. In future studies, these derived NDVI thresholds can be applied to determine the growing season of similar plant communities at other sites, which lack surface phenological data. Received: 29 November 1999 / Revised: 14 March 2000 / Accepted: 15 March 2000     

Morphological and genetic variation in Aegilops geniculata from Algeria

Aegilops geniculata Roth is an annual grass relative to cultivated wheats and is widely distributed in North Africa. In order to understand the diversity of this species, 14 populations collected in different bioclimatic areas in northern Algeria were analyzed using morphological and biochemical characters. Principal component analyses (PCA) based on the inflorescence characters and ecological parameters allowed the separation of populations in two mainly bioclimatic clusters characterized by different morphological patterns. Populations originated from humid and sub-humid coastal areas were characterized by vigorous spikes. Samples collected from intermediate and high mountains with humid and semi-arid conditions had long and lanceolate spikes. Individuals with small and narrow spikes were characteristics of steppic highlands in semi-arid conditions and high mountains with humid bioclimate. Individuals were distinguished successively by spike width, spike length, rachis length and awns number. Electrophoretic analyses of high molecular weight glutenin subunits (HMW-GS) based on the phenotypic variability and genetic distances revealed a significant variation within and between populations associated with bioclimatic conditions, in particular winter temperature. Genetic diversity was higher in populations growing under warm bioclimates than in those from cold bioclimates. These results suggest that a part of the variation for HMW glutenin variability is adaptive.     

Cloud forests of the Orinoco River Basin (Colombia): Variation in vegetation and soil macrofauna composition along the hydrometeorological gradient

Tropical montane cloud forests (TMCF) in the Orinoco River Basin are vulnerable to climate and regional land-use changes. These changes will force TMCF to migrate upwards, affecting biodiversity conservation and water flow regulation. Here, we evaluate how vegetation and soil macrofauna composition vary along the hydrometeorological gradient driven by an increase in fog incidence with elevation. Vegetation data were collected for all individuals with a diameter at breast height (DBH) > 5 cm in four vegetation plots (5 × 50 m; total: 0.1 ha) every 100 m in altitude between 1700 and 2200 m a.s.l. From each plot, we obtained three soil monoliths from the organic layer and three from the mineral horizon, and manually extracted their soil macrofauna. For these groups, we describe: (1) their compositional changes along the hydrometeorological gradient employing ordination analyses techniques and (2) the relation of the composition changes between vegetation and soil macrofauna communities using a symmetrical co-correspondence analysis. Our results show that the vegetation morphospecies composition and soil macrofauna-order composition vary significantly with the hydrometeorological gradient along elevation. The co-correspondence between vegetation and soil macrofauna reveals a shared breakpoint above the 2000 m a.s.l., where fog is more persistent. Furthermore, we identified eight indicator vegetation species and two soil macrofauna orders associated with specific elevations. These results suggest that under a climate-change-driven fog lift, the TMCF of the Orinoco River Basin will be displaced. Moreover, this study provides a baseline to monitor such displacement.     

近10年来蒙古高原植被覆盖变化对气候的响应

基于东亚干旱半干旱地区内蒙古和蒙古国67个气象站的观测资料和SPOTVEGETATION归一化植被指数(NDVI)数据,借助线性趋势、MK趋势性检验、最大化合成法和相关分析等常用数理统计方法,研究了内蒙古和蒙古国地区的植被覆盖变化和气候变化及其响应关系。结果表明:①近49年内蒙古和蒙古国地区年均气温显著上升,降水变化不明显。年均气温在空间上呈现出南高北低的空间分布格局,降水量表现出由西向东递增趋势。②空间分布上,内蒙的植被覆盖状况好于蒙古国。时间变化上,该地区植被覆盖变化分为2个阶段,1998—2001年NDVI呈整体退化趋势,2002—2012年波动上升,其中2009—2012年连续3a上升。空间变化上,内蒙古境内植被退化的区域主要集中在锡林郭勒盟周边地区,蒙古国境内退化的区域分布在中西部地区。③蒙古国境内荒漠和草原植被NDVI与降水呈正相关关系,与气温呈负相关。而对于内蒙古而言荒漠和草原植被的NDVI也与降水呈正相关关系,森林植被与气温呈正相关。就政策层面:内蒙古区域近年来受国家重大生态政策退耕还林、退牧还草的影响,大部分东部和西部植被恢复较快。在今后如果增强两国的文化和政策交流学习,将会对未来的游牧民族文化的保留和发展提供契机。     

Aquatic vegetation and hydrology of a braided river floodplain

The response of aquatic vegetation to the complex hydrology of a river floodplain was investigated on a stretch of former braided channels of the Rhône River near Lyon, France, which is fed by three different water inputs: underground water, surface flow from a small tributary and river overflow during spates. Water temperature, pH, conductivity, alkalinity, sulfate, nitrate, and phosphate content were measured monthly at seven sampling stations. Principal Component Analysis (PCA) of these data revealed two gradients: a gradient of spatial heterogeneity and a gradient of temporal fluctuations. A PCA of samples based on substrate grain size, flow velocity, channel width and depth, height and shade of bank vegetation suggested the division of the braided system into four zones. Along these former channels, the vegetation varies from communities with Potamogeton coloratus of nutrient-poor water, to meso-eutraphent communities with Callitriche platycarpa, Elodea canadensis, and Ranunculus trichophyllus. Correspondence Analysis (CA) of the floristic data revealed four zones. Regarding the habitat parameters investigated, one zone is assumed to be linked to the instability and the nutrient inputs of a former channel (running water from the tributary and flood disturbances), while another is linked to the stability and nutrient-poor conditions of the other former channel (supplied by underground water). The other two zones are considered as ecotones, each of them occurring in a former channel, upstream of the confluences. The location as well as the floristic and functional differences between these two ecotones are discussed.     

Distribution of cichlid fishes in the littoral of Lake Bacalar, Yucatan Peninsula

The distribution of cichlids in Lake Bacalar was assessed from January to September 1996, in eight shallow-water (< 2 m) stations, using a 20 m long seine net. Temperature, salinity/conductivity and dissolved oxygen were sensor-obtained; depth, submerged vegetation and bottom type were determined by visual inspection. Affinities between stations, based on fish abundance and environmental parameters, were analyzed by multivariate methods. Littoral of Bacalar town was the site with highest richness, diversity and abundance, probably promoted by the additional urban waste of organic matter. PCA defined two station-groups, one associated with muddy substrates, the other one with rocky/sandy bottoms. Cichlids are more abundant over muddy bottoms with abundant submerged vegetation, probably because of the abundance of prey and shelter.     

Interactive effects of vegetation structure and composition describe bird habitat associations in mixed broadleaf–conifer forest

The effects that changes in forest structure and composition have on wildlife have often been considered independently, such that the potential for interactive effects has received relatively little attention. We investigated the importance of vegetation structure, floristic composition, and their interaction for predicting bird distribution in mixed broadleaf–conifer forest. We collected vegetation and bird data at 979 stations in a watershed in southern Oregon in the spring of 2001. At each station, we described the vegetation using measures of structure (total vegetation volume) and of floristic composition (broadleaf–conifer composition). We then used logistic regression to model the probability of occurrence of bird species as a function of these 2 variables, their quadratic terms, and their interaction. Using stepwise model selection we identified the best model for each species and used area under the curve (AUC) scores to evaluate model performance. Of the 44 bird species we investigated, 20 had models with AUC scores ≥0.70. Of the best models for these 20 species, 1 included vegetation composition alone, 12 included just the main effects of vegetation composition and structure, and 7 included both the main effects and interaction terms. In summer of 2001 a wildfire burned 2,500 ha of the study area, resulting in substantial changes in the vegetation structure and composition. We used 4 yr of postfire bird and vegetation surveys to test the predictive performance of the habitat models for 9 species that occurred at >15% of the burned stations. Models for 3 of these species performed poorly (AUC < 0.7) in all 4 yr. For the other 6 species, predictive performance was low in the first year after fire and improved during subsequent years, suggesting a lagged response to changes in vegetation structure and composition. Quantifying the interactive effects of vegetation structure and composition improves our understanding of how birds respond to forest management and large-scale disturbances, such as wildfires. © 2011 The Wildlife Society.     

The human bioclimates of Western and South Pacific islands and climate change

The current bioclimates of equatorial Western and tropical South Pacific have been assessed, using the concepts of effective temperature and relative strain as a basis for evaluating likely changes in human comfort regimes as a consequence of global warming. Current bioclimates may be considered marginally stressful for indigenous populations. Global warming will result in changes in the frequency, duration and intensity of physioclimatically stressful conditions.     

Can Saturniidae moths be bioindicators? Spatial and temporal distribution in the Brazilian savannah

Some moths species are considered good indicators of habitat quality because they are very responsive to human disturbance, vegetation type, and successional processes. However, Saturniidae moths have not yet been considered as indicators of environmental quality. Little is known on the distribution of moth species in different vegetation types and the moths’ seasonal variations in the Brazilian savannah. Therefore, this study aims to describe the spatial distribution and temporal patterns of moths belonging to the Saturniidae family in two vegetation types—Cerrado sensu stricto on rocky outcrops and semi-deciduous forest—in both the rainy and dry seasons. It addresses the influence of the climatic seasons and vegetation types on abundance, richness, and species composition to describe the temporal and spatial distribution patterns and the relationship between the ecological aspects and the life history of these moths. This study was conducted in the Cerrado phytogeographical domain, in Pireneus State Park, Goiás, Brazil. The results revealed that most Saturniidae species sampled are present during the rainy season and typically found in forest habitats. Furthermore, a clear positive connection was found between the abundance pattern and rainfall seasonality and humid habitats; this is apparently related to the physiological tolerance of these moths, due to rudimentary mouthparts during their adulthood. Thus, rainfall and a forest habitat are important to and fundamental requirements for the persistence of the Saturniidae species in the Cerrado domain. Based on the results of this study, we suggest the use of saturniid species as indicators of changes in vegetation and climatic conditions.