SEIB–DGVM: A new Dynamic Global Vegetation Model using a spatially explicit individual-based approach

We report the development of a new spatially explicit individual-based Dynamic Global Vegetation Model (SEIB–DGVM), the first DGVM that can simulate the local interactions among individual trees within a spatially explicit virtual forest. In the model, a sample plot is placed at each grid box, and then the growth, competition, and decay of each individual tree within each plot is calculated by considering the environmental conditions for that tree as it relates to the trees that surround it. Based on these parameters only, the model simulated time lags between climate change and vegetation change. This time lags elongated when original biome was forest, because existing trees prevent newly establish trees from receiving enough sunlight and space to quickly replace the original vegetation. This time lags also elongated when horizontal heterogeneity of sunlight distribution was ignored, indicating the potential importance of horizontal heterogeneity for predicting transitional behavior of vegetation under changing climate. On a local scale, the model reproduced climate zone-specific patterns of succession, carbon dynamics, and water flux, although on a global scale, simulations were not always in agreement with observations. Because the SEIB–DGVM was formulated to the scale at which field biologists work, the measurements of relevant parameters and data comparisons are relatively straightforward, and the model should enable more robust modeling of terrestrial ecosystems.     

Experimental Assessment of Coral Reef Rehabilitation Following Blast Fishing

Abstract:  Illegal fishing with explosives has damaged coral reefs throughout Southeast Asia. In addition to killing fish and other organisms, the blasts shatter coral skeletons, leaving fields of broken rubble that shift in the current, abrading or burying new coral recruits, and thereby slowing or preventing reef recovery. Successful restoration and rehabilitation efforts can contribute to coral reef conservation. We used field experiments to assess the effectiveness of different low-cost methods for coral reef rehabilitation in Komodo National Park (KNP), Indonesia. Our experiments were conducted at three different spatial scales. At a scale of 1 × 1 m plots, we tested three different rehabilitation methods: rock piles, cement slabs, and netting pinned to the rubble. Significantly more corals per square meter grew on rocks, followed by cement, netting, and untreated rubble, although many plots were scattered by strong water current or buried by rubble after 2.5 years. To test the benefits of the most successful treatment, rocks, at more realistic scales, we established 10 × 10 m plots of rock piles at each of our nine sites in 2000. Three years after installation, coverage by hard corals on the rocks continued to increase, although rehabilitation in high current areas remained the most difficult. In 2002 rehabilitation efforts in KNP were increased over 6000 m² to test four rock pile designs at each of four rubble field sites. Assuming that there is an adequate larval supply, using rocks for simple, low-budget, large-scale rehabilitation appears to be a viable option for restoring the structural foundation of damaged reefs.     

硝基苯水溶液的超声波降解动力学

以硝基苯为唯一底物，选择超声功率200W，400W，600W，800W，研究了超声降解硝基苯水溶液的动力学，实验证明，硝基苯超声降解属假一级动力学反应，同时得到了不同超声功率下的降解速率常数，以及速率常数与超声功率的线性相关关系和含有超声功率的动力学方程，采用色质分析，确定了硝基苯降解产物中含有邻硝基酚和对硝基酚。     

Study of the dynamics of estuarine and coastal waters using remote sensing: the Tinto-Odiel estuary,SW Spain

This paper deals with the application of satellite images to characterize some aspects of the circulation dynamics of the Tinto-Odiel estuary using turbidity patterns as ‘natural tracers’. 15 images (Landsat TM and Spot HRV) were processed to provide synoptic, instantaneous views of the circulation patterns under different environmental conditions. In addition, a comparison was made between results of oceanographic field work, using biplanes and fluorescent tracers, and satellite image turbidity patterns used as ‘ground truth’ data for specific hydroclimatic situations. This approach allowed (1) the identification and mapping of dynamic processes of interest during a theoretical tidal cycle, (2) the elaboration of additional information on the ‘flow schemes’ at the mouth of the estuary with improved spatial and temporal resolution, and (3) the supply of basic data to improve the knowledge of exchange processes between estuarine and coastal waters. The results of this study are considered to be useful for the management of the estuarine system.     

露天开采生态环境影响识别与修复技术的探讨——以崇阳露天石煤钒矿矿山开发环评为例

矿山开采活动在获得最大的经济利益的同时,势必给原有的生态环境带来严重破坏和影响.结合矾矿露天采矿特点,讨论矿山开采各个环节对生态因子的影响及强度,筛选主要影响因子,分析露天矿山开采可能引起的地形地貌、土地占用、土壤侵蚀、破坏野生动植物生境、地表水水质、景观格局等方面对环境的影响,并提出相应的优化施工方案、闭坑露天矿山土地、植被复垦等生态环境保护对策,对科学开发崇阳钒矿具有一定参考意义.     

Effects of Restoring Oak Savannas on Bird Communities and Populations

Abstract:  Efforts to restore and maintain oak savannas in North America, with emphasis on the use of prescribed fire, have become common. Little is known, however, about how restoration affects animal populations, especially those of birds. I compared the breeding densities, community structure, and reproductive success of birds in oak savannas maintained by prescribed fire (12 sites) with those in closed-canopy forests (13 sites). All sampling was conducted in Illinois (U.S.A.). Of the 31 bird species analyzed, 12 were more common in savannas, 14 were not affected by habitat structure, and 5 were more common in forest habitat. The species favored by disturbance and restoration included Northern Bobwhites ( Colinus virginianus ), Mourning Doves (  Zenaida macroura ), Red-headed Woodpeckers (  Melanerpes erythrocephalus ), Indigo Buntings (  Passerina cyanea ), and Baltimore Orioles ( Icterus galbula ). Those more common in closed-canopy forest included Ovenbirds ( Seiurus aurocapilla ) and Wood Thrushes (  Hylocichla mustelina ). Few species were unique to one type of habitat, but overall avian community structure in oak savannas and closed-canopy forests was generally distinctive. Estimates of nesting success (derived from 785 nests) revealed that 6 of the 13 species considered experienced greater productivity in the savanna habitat. Rates of brood parasitism were unaffected by restoration and habitat structure. Within savannas, tract size had little effect on breeding abundances and reproductive success. My results illustrate that restoration techniques can significantly affect the ecology of constituent animal populations and communities and have key implications regarding avian conservation and the management of forest habitat in fragmented landscapes. Small patches of forest habitat that regularly function as population sinks may offer far better prospects for birds if they are subjected to disturbance and ecosystem restoration.     

Family structure influences mate choice in white-fronted bee-eaters

White-fronted bee-eaters live in patrilocal, extended family groups in which several pairs may breed simultaneously and in which helping behavior by nonbreeders is common. The composition of a male's family, and his social position within it, are major predictors of his expected reproductive success. For females, the dispersing sex, a decision to pair necessitates forfeiting any potential fitness benefits available through helping in her family, in favor of the potential benefits of breeding in the male's family. Using a set of equations that incorporate the social and non-social predictors of nesting success, we develop a payoff matrix for the expected fitness (current and future) of pairing with different categories of males. Predictions generated from this payoff matrix were supported by data: (1) Females that could help close kin (and thus garner large indirect benefits) tended to remain unpaired. (2) Males with social characteristics associated with low expected reproductive success were more often rejected as potential mates by females. (3) High-quality males, those with potential helpers of their own, were nearly always paired. Simulation analyses were used to investigate female pairing decisions in more detail, and to test various hypotheses about possible decision rules. We demonstrate that pairing females incorporate an assessment of the family structure of potential partners into their mate choice decisions. Such social characters represent an aspect of female choice that has been underappreciated. We suggest that social characters will prove to be important components of mate choice decisions in many species where kinship and dominance considerations influence the likelihood, or success, of breeding.     

Sustainability of sand dune restoration along the coast of the Tyrrhenian sea

This study reports the results of restoration management on sand dune environments along the coastal belt of the Castelporziano nature reserve (Rome, Italy) and the subsequent monitoring phases to test the sustainability of the ‘soft techniques’ applied. In the area concerned, over a length of ca. 3 km, 40 dunes were built up along with three belts located at <40 m, 40–70 m, and >70 m, respectively, from the shoreline. On each of 38 dunes 20 individuals ofAmmophila littoralis were planted; this species is one of the local autochthonous species considered particularly suitable for stabilizing sand dunes. After one year, two years and five years, respectively the changes in height and surface of each dune, the survival rates ofA. littoralis, and its changes in cover, the appearance of new shoots and the establishment of new species were observed. A progressive increase in species number, which five years after the restoration amounted to about 60% of those characterizing the natural dunes, was reported indicating a progressive trend towards populations similar to natural ones. In the colonization of new species there is a prevalence of theSporobolus-Elymetum farcti and theSalsolo Kali-Cakiletum maritimae association, while the species established successively refer to theEchinophoro spinosae-Ammophiletum arundinaceae association and theCrucianellion maritimae alliance as occurring in natural successions. This succession runs parallel to the natural dune colonization processes. In particular, the data regarding survival, cover and number of vegetative shoots indicate that the dune belt between 40 and 70 m from the sea is the one most suitable for restoration. Some changes in dune morphology was observed: the height of the artificial dunes tended to decrease considerably in the five years of observation, whereas a progressive increase in their surface area was observed. During the study period.A littoralis favoured the establishment of new species, but as yet exercises no action on increasing dune height.     

洞庭湖区退田还湖生态补偿机制

以洞庭湖区退田还湖的生态补偿为例,初步探讨了有关生态补偿的3个基本问题,即补偿支付者和接受者的问题,补偿强度的问题和补偿渠道的问题。     

Modelling forest succession in two southeastern Canadian mixedwood ecosystem types using the ZELIG model

The gap model ZELIG was validated for red spruce–balsam fir–yellow birch and yellow birch–sugar maple–balsam fir forest types in southern Quebec, Canada. Long-term historical data originating from the Lake Edward Experimental Forest, La Mauricie National Park, were used. The effect of the variation in plot size, representing the space within which trees uptake site resources, was also examined. Several species were included in both forest types: red spruce (Picea rubens Sarg.), balsam fir (Abies balsamea (L.) Mill.), yellow birch (Betula alleghaniensis Britton), white birch (Betula papyrifera Marsh.), red maple (Acer rubrum L.), sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), eastern hemlock (Tsuga canadensis (L.) Carr.) and northern white cedar (Thuja occidentalis L.). The pattern of change in basal area growth varied among species, ranging from a steady increase to a more or less rapid decline. There was a good agreement between observations and predictions for yellow birch, red spruce, red maple, sugar maple, balsam fir and northern white cedar. Plot size had a significant impact on the dynamics of the different species. Depending on the species, the decline was accelerated, the amplitude of the fluctuations varied, or the maximum basal area reached changed. Predicted regeneration varied among species and the number of seedlings generally increased with increase in plot size. The pattern of development for most species was related to their life characteristics. The results highlighted the fact that there is a critical lack of knowledge and data on the dynamics of regeneration from the seedling to the sapling stages for the two forest types studied, which resulted in poor predictions for some species. As the life characteristics varied among species, the use of only one plot size for all species may not be realistic.