Involving wetland protection policies in the simulation of the wetland biodiversity pattern has the potential to improve the accuracy of policy-making. In this research, by combining the Cellular Automata Markov Model (CA-Markov) for land use change simulation and a wetland Biodiversity Estimation Model Based on Hydrological Pattern and Connectivity (BEHPC), we put forward a comprehensive framework that integrates policy stage division, the identification of stage characteristics, and biodiversity prediction. This framework divided the wetland conservation policies implemented in the study area into three stages: promoting (1995−2005), strengthening (2005–2010), and stabilizing (2010–2020). CA-Markov verification confirmed the stages’ consistency with actual policy implementation, indicating its usability. Using the land use data of different policy stages as input for the CA-Markov model, we then predicted the wetland biodiversity pattern in 2030 under different scenarios. The results showed that the land use and wetland protection policies implemented during 2010–2020 were most beneficial for enhancing wetland biodiversity in the study area, with an expected increase of about 8% if continued. This study offers technical and scheme references for the future evaluation of wetland-related policies at the regional scale. It also provides guidance for optimizing the spatial structure and providing numerical goals for land use and wetland protection.

The hydrological environment of wetlands is vital for ensuring the stable development of their ecological functions. However, previous sample-scale studies have failed to capture the spatial heterogeneity of the hydrology-function relationship. The objective of this study is to elucidate the hydrological driving mechanisms responsible for the formation of and changes in the spatial patterns of wetland functions at different spatial and time scales. This study established a multi-dimensional hydrological element and wetland function index system through space technology and multi-source remote sensing images and proposed a multi-scale hydrology-function relationship analysis framework to reveal the relationships between hydrological elements and wetland function spatial patterns at different spatial and temporal scales. The final results demonstrated that, at different spatial and time scales, increasing water coverage contributes greatly to the improvement of habitat, soil conservation, and water supply functions, and increasing the flooding frequency and connectivity structure are more effective at improving the water purification function. At the grid scale, the proportion of grids with medium or strong correlations ranges from 26.63 % to 51.19 %, whereas with respect to temporal correlations, the proportion of grids with medium or strong correlations ranges from 50.67 % to 92.76 %, indicating a pronounced scale effect and spatial heterogeneity of the hydrology-function relationship. The opposite relationships between hydrological elements and functions in some grids (with proportions ranging from 9.89 % to 37.38 %) may result from geographical, environmental constraints, which disrupt the normal correlation between hydrological elements and wetland functions. This study contributes to a deep understanding of the hydrological driving mechanism of wetland functional patterns and provides guidance for wetland protection and restoration planning and hydrological condition regulation by developing specific strategies for improving ecological function.

Hydrological connectivity is crucial for the healthy operation of wetland ecosystems. However, the current design of ecological corridors in wetland biodiversity networks is mostly based on species migration resistance, neglecting the important role of hydrological connectivity. How to incorporate hydrological connectivity into the wetland ecological corridor system (ECS) is still unclear. To answer the question, we proposed a framework for constructing a wetland ECS with the goal of improving conservation value of previously identified wetland biodiversity hotspots based on hydrological connectivity. In the proposed framework, we clarified the function-level-dimension of each corridor based on the dynamics of conservation value of biodiversity hotspots, the hierarchical classification of rivers and the dimension of hydrological connectivity. Then we determined the spatial distribution and functional zoning of the corridors by least cost model (LCM) using indicators that reflect wetland hydrological connectivity resistance, including water coverage, water use efficiency of vegetation, and land use suitability. The results are as follows: (1) to improve the overall hydrological connectivity and conservation value of biodiversity hotspots, 25 corridors should be constructed for vertical hydrological connectivity (with 3 for maintaining the status quo, 6 for improving and 16 for restoring connectivity) and 3 corridors should be constructed for lateral hydrological connectivity; (2) total area of all corridors are 11 km2, accounting for 6.79% of the study area (2.47% of core zone and 4.32% of buffer zone); (3) low suitability areas of hydrological vegetation gradient (HVG) are the most extensive, followed by low suitability areas of land use/cover change (LUCC) and the average fraction coverage of water surface (AFCW), accounting for 65.08%, 47.87% and 6.76% of the corridor coverage, respectively. The proposed framework of constructing wetland ECS in this study has the potential to provide the post-2020 global biodiversity framework and sustainable development goals with specific technical support and more targeted-control strategies for building a hydrological connected wetland biodiversity network.

The conflict between grain production and wetland resource protection in plain wetland is prominent. Understanding the future impacts of current land use policies on wetlands is the key to rationally evaluating and adjusting these policies. Therefore, the objective of the research was to predict the potential distribution of Sanjiang plain wetland under the current land use and protection policy using remote sensing images and CA Markov models. Methodologically, Landsat TM remote sensing images of the Sanjiang Plain (2010–2020) were used to extract wetland distribution based on object-oriented methods, and the characteristics and patterns of wetland change caused by the land use and protection policies during this period were analyzed. A CA–Markov model was used to predict the potential distribution of Sanjiang Plain wetland in 2030, 2040, 2050, and 2060. Then, we summarized the advantages and disadvantages of current land use policies and put forward adjustment measures. The results indicate that during 2010 and 2020, the wetland area of Sanjiang Plain decreased by 22.34%. The conversion ratio of wetland to non-wetland type (mainly farmland) in the first half and the second half of the decade was 46.41% and 15.31%, respectively, and the decrease in wetland showed an obvious slowing trend. The spatial distribution prediction in future showed that the wetland area will continue to decline in 2030, and the decline will basically stop in 2040. Finally, the proportion of wetland area will remain at 8.68% of the total area of Sanjiang Plain, with that of some counties and cities less than 5%. It is concluded that, although the current land use policies in Sanjiang Plain can effectively slow down the wetland area shrinking and stabilize the spatial pattern, a very low proportion of wetland area in some areas will make it difficult for the wetland ecosystem to exert ecological functions and ensure regional ecological security. The wetland conservation managers should adjust the current land use policies according to relevant requirements of farmland protection policies and restore the areal proportion and spatial pattern of wetland in order to help with regional sustainable development.

Plants utilize different strategies in different environments to maximize population expansion. Understanding plant reproductive strategies in heterogeneous habitats is therefore important for explaining plant ecological adaptability, and for effectively managing and conserving ecosystems. We wanted to explore the reproductive strategy transformation of D. angustifolia in heterogeneous habitats, as well as the environmental factors driving and affecting its reproductive characteristics. To do this we measured the reproductive characteristics of D. angustifolia, as well as the soil physical and chemical properties of these heterogeneous habitats. The density, biomass per unit area, and proportion of aboveground biomass in swampy meadows were significantly higher compared to other habitats. The proportion of rhizome node buds gradually increased from swampy to typical to miscellaneous grass meadows, while the proportion of tillering node buds decreased. The allocation of sexual reproduction within D. angustifolia populations was significantly and positively correlated with plant rhizome biomass and negatively correlated with the number of tillering node buds. The propagation strategies of D. angustifolia in heterogeneous habitats were consistent with CSR theory (Competitor, Stress-tolerator, and Ruderal). The proportions of inflorescence (2.07 ± 0.52%; 1.01 ± 0.15%) and root (23.8 ± 1.5%; 19.6 ± 1.4%) biomass in miscellaneous and typical meadows were high, which tended toward the “Ruderal” adaptation strategy. In swampy meadow, D. angustifolia invested mostly in vegetative growth to produce tiller node buds (14426.67 buds/m2; 46%) and ramets (1327.11 ± 102.10 plants/m2), which is characteristic of the “Competitor” strategy. Swamp D. angustifolia resisted flooding by maintaining a resource balance in its body, and was therefore biased toward the “Stress-tolerator” strategy. Environmental factors accounted for 74.63% of reproductive characteristic variation, in which the interpretative proportions of soil water content, dissolved organic carbon, ammonia nitrogen, and nitrate nitrogen were significant (p < 0.01). When soil water content, dissolved organic carbon, and nitrate nitrogen increased, D. angustifolia tended toward the C strategy; in contrast, when soil water content decreased, amine nitrogen and available phosphorus increased, and D. angustifolia tended toward the R strategy. In a stressful environment, the escape mechanism constitutes an increased rhizome and sexual reproduction investment. In contrast, for suitable habitats, tillering node buds increased in order to expand the population via new plant production, which was the propagation strategy of D. angustifolia in heterogeneous habitats.

掌握森林生物量的时间变化特征和空间分布,有意于碳达峰、碳中和目标的实现,以及应对气候变化具有重要意义.本文分析了 2013 年至 2021 年黑龙江省东部山区森林生物量及其地形因子之间的关系.结果表明,研究区森林生物量多年均值为 9.58 t,生物量增加区域要多于减少区域;高程在 400 m左右的森林生物量占比最多,缓坡和北坡的生物量占比较高.

Wetland destruction and degradation have been increasing gradually. The biodiversity of the remaining wetlands is under unprecedented threat. Identifying the future trend of wetland biodiversity is a critical step to provide early warnings for wetland biodiversity protection and management. However, studies have focused mainly on the current biodiversity assessment and protection, without emphasizing on the prediction of future changes. Combining the advantages of the key indicators of wetland biodiversity simulation (wetland pattern and hydrological connectivity; PHC) and CA_Markov of land use prediction, this study proposes a prediction framework for wetland biodiversity. Taking Sanjiang Plain as an example, this study predicted the changing trend of wetland biodiversity in the study area and evaluated the potential loss of wetland biodiversity in each reserve. The results revealed that the cultivated land occupation mainly caused the change in the spatial patterns of wetland biodiversity in the study area. According to the land use development trend from 2010 to 2015, the indexes of wetland PHC in the study area will decline significantly from 2020 to 2030, and the wetland biodiversity predicted by our framework will be transformed from the medium to the low level (the biodiversity conservation value will decrease 7.40% on average, with the wetland area reduced by 2.74%). Each reserve in the study area will experience various degrees of degradation in biodiversity due to the decrease in hydrological connectivity. The framework of wetland biodiversity prediction proposed in this study can provide technical support for predicting the changing trend in wetland biodiversity at the regional scale and a reference for long-term protection and monitoring strategies of wetland biodiversity at the reserve scale as an early warning.

Human activities, especially cultivated-land reclamation, substantially influence landscape patterns. This phenomenon leads to a sharp decrease in wetland areas and wetland function degradation. To understand the impact of changing landscape patterns of the cultivated land on remnant wetland degradation and to formulate highly targeted control measures, considering a farmland-wetland mosaic landscape in the Sanjiang Plain as an example, this study explored the response of soil- and vegetation-related indicators of remnant wetlands under the influence of changing cultivated land patterns. Correlations between cultivated land patterns and soil- and vegetation-indicators in different buffer zones of remnant wetland sample points were discussed. On the basis of modeling an index of the integrated degradation degree of remnant wetlands (IDRWs) using soil- and vegetation-indicators, the correlation between cultivated land patterns and IDRW was analysed. The results showed that: 1) five soil-related indexes of remnant wetlands were lower than those of natural wetlands, and nine vegetation-related indexes of remnant wetlands were higher than those of natural wetlands; 2) the variation in soil- and vegetarian-related indexes caused by changing cultivated land patterns in a certain range of remnant wetlands was significant (P < 0.05) and these indexes could potentially be used as variables to model IDRW; and 3) the aggregation degree of wetland patches was the main landscape index for IDRW simulation (from 1995 to 2015, the proportion of serious degradation of the Sanjiang Plain wetland first decreased in 2010 and then increased, and that of slight degradation first increased in 2010 and then decreased, indicating that wetland protection and restoration plans have shown progress after 2010). Our study discussed the impacts of cultivated land patterns on remnant wetland degradation and developed a simulation method of degraded remnant wetlands to provide a reference for the wetland protection, restoration, degradation monitoring, and reclamation planning for the cultivated lands in the future.

Wetlands are important ecosystems for biodiversity preservation and environmental regulation. However, the integrity of wetland ecosystems has been seriously compromised and damaged due to the reckless and indiscriminate exploitation of wetland resources during economic development by human society. Hence, wetland restoration has now attracted wide attention. Understanding wetland restoration suitability and its relationship with river grade and river distance is an important step in further implementing wetland restoration and ensuring an orderly wetland development and utilization. In this study, wetland restoration suitability is evaluated combining natural and human factors. Taking its result as an important basis, the spatial distribution characteristics of different levels of wetland restoration suitability are discussed for the studied region; the percentage distribution of different levels of wetland restoration suitability is analyzed for 10 km long buffer zones of rivers of different grades, and the association between the distribution of different levels of wetland restoration suitability and the river distance (2, 4, 6, 8, and 10 km) is also analyzed for different buffer zones of rivers in different grades. Our findings show that the spatial distribution of wetland restoration suitability is closely associated with the grade of rivers and the distance of the wetland patches from the river. The higher the river grade, the higher the percentage of the wetland with high restoration suitability within the same river distance. The percentage of wetlands with high restoration suitability has shown a notably decreasing trend as the river distance increases for the areas beside rivers of all grades, while the percentage of a wetland area with relatively high restoration suitability tends to increase as the river distance increases for the areas beside rivers of grade I and II and does not have a noticeable trend to change as the river distance changes for the area beside rivers of other grades. Results of this can provide technical support for wetland restoration suitability evaluation for plain areas, a spatial reference for wetland restoration prioritizing, and an orderly wetland development and utilization in future studies and planning.

A high biodiversity conservation value of a specific area generally indicates biodiversity priorities, making biodiversity conservation planning more reasonable. However, the spatial prioritization of biodiversity cannot easily indicate temporal changes because the data of many species are difficult to obtain in even a single period, let alone repeated surveys. Here, we show that the easily available wetland hydrological pattern and connectivity (HCP) variables are effective surrogates for the monitoring of biodiversity conservation value. We used the Systematic Conservation Planning (SCP) method to evaluate the historical biodiversity conservation value (BCV), represented by Irreplaceability Index, by integrating the predicted spatial distribution of biodiversity features in 1995. We then calculated the wetland HPC indexes in randomly setup samples within a certain radius and analysed the correlation between the BCV and HPC indexes with a regression method. Finally, we further simulated the numerical and spatial changes of the BCV in different periods to illustrate its variation regularity. We found that the BCV considerably decreased in the study area. In conclusion, we confirmed that the wetland HPC indexes are significantly correlated with and can simulate the BCV indicator. We further identified the spatial locations of these degraded areas and proposed conservation and restoration scenarios for the study area. This study verified the impacts of HPC changes on wetland biodiversity caused by human-induced land use change; it also provides a reference for long-term assessment of wetland biodiversity change. SIGNIFICANCE STATEMENT: Among other abilities, effective biodiversity conservation should have the abilities to both prioritize the conservation value and detect its spatial changes. However, the assessment of biodiversity conservation value needs sufficient and high-quality species occurrence data and multi-period comparison. Here, we find that the relatively well accessible wetland hydrological pattern and connectivity indexes are effective surrogates for the change detection of wetland biodiversity conservation value. This means that wetland biodiversity conservation planners can monitor the biodiversity conservation situations without resource-consuming investigations to obtain species' occurrence data and repeated prioritization of the conservation value.

火山岩母质发育的土壤孕育了结构功能独特的土壤微生物群落.为评估火山生态系统土壤微生物的代谢多样性及其影响因素,选择五大连池火山群为研究对象,基于"时空替代"的研究方法,利用Biolog微平板技术,分析不同地质年代火山南北两个坡向的土壤微生物碳源代谢多样性,结合土壤理化指标进一步分析影响土壤微生物碳源代谢多样性的环境因子.结果表明:不同地质年代火山土壤微生物群落功能多样性存在显著差异.平均颜色变化率(AWCD)随培养时间延长而逐渐增加,南坡AWCD值随土壤发育时间增加而增加,北坡AWCD值无明显变化规律.土壤微生物碳源代谢的指数速率(P值)和潜力(K值)南北坡存在差异显著.主成分分析结果表明,南坡主成分1和主成分2分别能解释变量方差的80.85％和12.54％,土壤微生物的碳源代谢格局差异主要是由糖类(CH)和酯类(ES)引起的,二者共解释总变异量的64.93％;北坡主成分1和主成分2分别能解释变量方差的70.13％和19.77％,土壤微生物的碳源代谢格局差异主要是由带磷基糖类(CH.P)和酯类(ES)引起的,二者共解释总变异量的80.41％.冗余分析表明,土壤速效磷、总有机碳、铵态氮、pH、C:N和N:P等显著影响微生物功能多样性及碳源代谢类型.研究结果为进一步探讨土壤发育过程中微生物功能多样性演化的驱动机制提供参考.

The conservation management of biodiversity hotspots is of vital significance for biological conservation. For wetlands, which are a special type of ecosystems that are based on water as their main medium, a decline in external hydrological connectivity often leads to wetland degradation inside biodiversity hotspots. In this context, the relationship between hydrological connectivity changes inside and outside hotspots is worth exploring. Based on the wetland biodiversity hotspots identified using systematic conservation planning, this study selected eight representative biodiversity hotspots with concentrated area. Integral index of connectivity, probability of connectivity (representing structural connectivity), and morphological spatial pattern analysis (representing functional connectivity) were used to analyze the hydrological connectivity changes inside various hotspots for 1995–2015. By taking the catchment area involved as the minimum basin perimeter, this study calculated the external hydrological connectivity changes of various hotspots during this period and analyzed the relationship between hydrological connectivity changes inside and outside of hotspots. The internal and external hydrological connectivity of wetland biodiversity hotspots were found to be significantly correlated. Moreover, the internal hydrological connectivity of hotspots not only declined with declining external structural connectivity, but also changed with the proportion of core wetlands, the proportion of edge wetlands, and the proportion of branch corridors. In addition, hotspots located at intersections of high-grade rivers were more significantly affected by climate change than by human activities and their hydrological connectivity increased with increasing rainfall. The internal hydrological connectivity of hotspots near low-grade rivers presented a declining trend, mainly because of human activities. This study clarified the relationship between internal and external hydrological connectivity of wetland biodiversity hotspots. Targeted internal and external control strategies are proposed, with the aim to offer references for the conservation of wetland biodiversity.

选取挠力河流域作为研究区域,采取层次分析评价方法,选取人口密度、人类干扰指数、垦殖系数、净初生产力、生物丰度等11个评价指标,对2005至2015年,挠力河流域生态系统的承载能力进行评价.结果显示,10年间区域内生态系统承载力指数呈持续下降趋势,从不同生态系统类型角度出发,森林、湿地以及农田的生态系统承载能力总体下降,草地和城镇生态系统承载力先降低后上升,总体呈下降趋势.

[目的]明确火山喷发后森林生态系统长期发展演化过程中土壤微生物量的变化特征.[方法]采用空间代替时间的方法,选择五大连池火山群中的老黑山(1721年喷发)、东焦得布山(17万年前喷发)、小孤山(28万年前喷发)、尾山(40万年前喷发)和北格拉球山(70万年前喷发)构成土壤发育的时间序列,分析土壤微生物量碳和氮含量以及土壤理化因子,探索火山喷发形成后森林生态系统长期演化过程中土壤微生物量的时间动态及其影响因子.[结果]随火山喷发形成时间增加,微生物量碳含量总体呈先增加后减少再增加的趋势;微生物量氮总体呈先增加后减少的趋势.土壤微生物量在南坡和北坡上差异显著,数量上表现为北坡＞南坡.土壤微生物量碳和氮对土壤总有机碳和全氮的贡献率分别为0.92％～3.03％和1.19％～6.33％,表层(0～10 cm)高于底层(10～20 cm),贡献率的时间变化特征与土壤微生物量碳和氮的时间变化特征基本一致.土壤微生物量碳和氮呈极显著正相关;随火山喷发时间的延长,土壤微生物量与理化因子的相关程度下降.[结论]不同喷发时期火山土壤微生物量及其对土壤养分的贡献率呈波动性变化特征,不同坡向和土层深度土壤微生物量含量存在明显分异,土壤养分对微生物生存发展的限制作用随生态系统发育时间延长而降低.

火山熔岩生境孕育了独特的土壤微生物群落.为了解火山生态系统土壤细菌群落多样性和群落结构及其关键影响因子,选择五大连池新、老期火山为研究样点,非火山为对照,基于高通量测序方法,分析不同采样点土壤细菌群落结构和多样性,结合土壤理化指标,进一步分析影响火山生态系统土壤细菌群落多样性的环境因子.结果 表明:细菌操作分类单元(OTUs)、Ace指数、Chao1指数和Simpson指数变化趋势一致,表现为非火山＞新期火山＞老期火山.三个样点土壤的共有OUTs数量为713个,各自特有的OTUs数量不尽相同.三个样点土壤中检测到共有细菌16个类群,其中变形菌门、酸杆菌门、放线菌门和绿弯菌门为优势菌群,老期火山土壤中酸杆菌门、疣微菌门、Rokubacteria相对丰度最大,而Patescibacteria相对丰度最小.三个样点的土壤细菌群落具有明显的空间关系,相似性差异较大,但不符合随地理距离的增加而降低的模型.土壤理化性质测定结果标明:老期火山土壤pH、有机质、全氮、全磷、铵态氮和硝态氮显著高于新期火山和非火山,新期火山土壤含水量和速效磷显著低于老期火山和非火山.喷发时间和火成岩基质等特性会导致不同火山土壤理化性质的差异,进而影响土壤细菌多样性和群落结构.Pearson相关性分析表明:土壤pH显著影响细菌的多样性指数.冗余分析(RDA)结果表明:土壤氮含量、pH和有机质是影响火山森林生态系统土壤细菌群落结构的主要因子.

城市建设、农业开垦等人类活动影响导致湿地面积锐减、生态功能退化及生物多样性丧失,严重威胁到生态安全与区域可持续发展.湿地的保护与恢复得到国内外学者的广泛关注.区域尺度上的湿地恢复适宜性空间量化评估,有利于降低湿地恢复的复杂程度和恢复成本.本文以三江平原为研究对象,通过对土壤、植被、水文、地形等自然影响因子和土地利用年限、利用强度等社会经济因子的分析,揭示影响湿地恢复适宜性的关键因素,并对湿地恢复适宜性进行评价,确定三江平原恢复可能性高的关键区,以指导三江平原退化湿地的恢复.对三江平原湿地的恢复优先性评价,将有效促进我国北方内陆湿地保护与恢复的研究进展,在此基础上建立湿地恢复优化网络可为湿地管理者和决策者提供科学的参考,同时也为湿地恢复潜力评估和恢复策略的制定提供基本体系框架.

Large-scale human activities especially the destruction of forest land, grassland, and unused land result in a large amount of carbon release into the atmosphere and cause drastic changes in land use/cover in the Sanjiang Plain. As a climate change-sensitive and ecologically vulnerable area, the Sanjiang Plain ecosystem's carbon cycle is affected by significant climate change. Therefore, it is important that studying the impact of the changes in land use/cover and climate on vegetation carbon storage in the Sanjiang Plain. Remote sensing, temperature, and precipitation data in four periods from 2001 to 2015 are used as bases in conducting an analysis of land use/cove types and spatio-temporal variation of vegetation carbon density and carbon storage in growing season using model and related analysis methods. Moreover, the impact of land use/cover change and climate change on vegetation carbon density and carbon storage is discussed. The findings are as follows. (1) Cultivated land in the Sanjiang Plain increased, while forest land, grassland and unused land generally decreased. (2) Vegetation carbon density increased, in which the average carbon density of cultivated land, grassland, and unused land varied insignificantly, while that of forest land increased continuously from 4.18 kg C/m(2) in 2001 to 7.65 kg C/m(2) in 2015. Vegetation carbon storage increased from 159.18 Tg C in 2001 to 256.83 Tg C in 2015, of which vegetation carbon storage of forest land contributed 94% and 97%, respectively. (3) Conversion of land use/cover types resulted in a 22.76-TgC loss of vegetation carbon storage. Although the forest land area decreased by 3389.5 km(2), vegetation carbon storage in the research area increased by 97.65 Tg C owing to the increase of forest carbon density. (4) Pixel-by-pixel analysis showed that vegetation carbon storage in the majority of the areas of the Sanjiang Plain are negatively correlated with temperature and positively correlated with precipitation. The results showed that changes of land use/cover types and vegetation carbon density directly lead to a change in vegetation carbon storage, with the change of forest vegetation carbon density being the main driver affecting vegetation carbon storage variation. The increase of temperature mainly suppresses the vegetation carbon density, and the increase of precipitation mainly promotes it.

基于2010～2015年MODIS-NDVI的月数据、土地利用数据,分析挠力河流域生态系统生产能力的时空变化特征.结果表明,2005～2015年,挠力河流域生产能力指数EPI的平均值分别为62.11、58.13、66.91,标准差为12.78、13.86、13.99.总体表明,挠力河流域生态系统生产力水平从2005年到2010年呈下降趋势,减小了6.41％,2010年到2015年呈上升趋势,增加了15.10％.从生态系统类型的角度进行分析,2005～2015年,森林生态系统对整体区域的生产能力贡献最大,依次为农田生态系统、草地生态系统、城镇生态系统和湿地生态系统的生产能力最弱.

五大连池火山熔岩台地是一种火山地貌,研究熔岩台地草本物种分布及其环境解释,对认识火山原生演替过程中植物群落空间格局形成及适应机制具有重要意义.本文以五大连池熔岩台地的草本物种为研究对象,调查了苔藓、草本、灌丛、阔叶林和针阔混交林等不同植被类型中的草本层样方,并测定样方中的土壤养分和水分等状况,采用多样性指数、优势度指数、均匀度指数、物种丰富度评价草本层物种多样性,通过典范对应分析方法研究了群落组成与土壤因子的关系.结果 表明:(1)熔岩台地草本层物种丰富,共56种,占本研究调查区总物种数的82.35％,草本样地的草本层物种多样性、优势度和均匀性高于其他植被类型.(2)熔岩台地土壤pH值对群落草本层物种丰富度和物种个体的空间分布均有较大影响.(3)土壤因子解释了群落分布的79.39％,其中土壤pH值、速效磷、硝态氮、铵态氮所占的解释量比较大.(4)岩败酱(Patrinia rupestris)、万年蒿(Artemisia sacrorum)、硬质早熟禾(Poa sphondylodes)和中华苦荬菜(Ixeris chinensis)对环境要求较低,能够适应熔岩台地土壤贫瘠恶劣的环境.熔岩台地不同植被类型表现出对环境资源的特定需求,熔岩地貌导致了土壤pH值、养分、水分的差异,并影响植物群落的分布.

土壤微生物群落是陆地生态系统的重要生物活性成分,其结构和功能多样性直接影响到系统的碳、氮等生态过程,微生物群落功能多样性与地上植被类型变化密切相关,开展植被类型对土壤微生物群落功能多样性的影响研究具有重要意义。以五大连池新期火山熔岩台地苔藓、草本、灌丛、矮曲林、针阔混交林5种典型植被类型为对象,利用BIOLOG微孔板法研究不同演替阶段植被类型土壤微生物群落功能多样性特征。结果表明:不同植被类型土壤微生物群落功能多样性存在显著差异。平均颜色变化率（AWCD）随培养时间延长而逐渐增加,大小顺序为:苔藓＞针阔混交林＞矮曲林＞草本＞灌丛。灌丛土壤微生物多样性指数与其他植被类型间差异显著。主成分分析结果表明,主成分1和主成分2分别能解释变量方差的56.24%和29.59%,不同植被类型下土壤微生物的碳源利用格局差异主要是由氨基酸类和带磷基糖类引起,二者合计解释总变异量的47.51%。冗余分析表明,速效磷、铵态氮、C∶N和pH对微生物功能多样性具有显著的影响,羧酸类、氨基酸类、酯类和胺类的降解更易受到环境因素的影响。研究结果为进一步探讨植被类型与土壤微生物之间在植被演替过程中的关系提供参考。