The use of historical range and variability (HRV) in landscape management

This paper examines the past, present, and future use of the concept of historical range and variability (HRV) in land management. The history, central concepts, benefits, and limitations of HRV are presented along with a discussion on the value of HRV in a changing world with rapid climate warming, exotic species invasions, and increased land development. This paper is meant as a reference on the strengths and limitations of applying HRV in land management. Applications of the HRV concept have specific contexts, constraints, and conditions that are relevant to any application and are influential to the extent to which the concept is applied. These conditions notwithstanding, we suggest that the HRV concept offers an objective reference for many applications, and it still offers a comprehensive reference for the short-term and possible long-term management of our nation's landscapes until advances in technology and ecological research provide more suitable and viable approaches in theory and application.     

鄱阳湖水位特征与湿地生态保护

从分析江湖关系入手，研究鄱阳湖的水位及湿地生态特征，并提出人工控湖等加强湿地生态保护的对策建议。     

生态公益林效益发挥的保障机制

文章具体阐述了生态公益林的多重效益和对生态公益林保护建设的生态补偿机制进行了探讨。     

西部退耕还林(草)工程生态与经济协调发展途径的选择

通过农民问卷调查结果和退耕还林(草)工程特点的分析,以解决农民关心的焦点问题和反映工程的两重性特点为依据,提出实现退耕还林(草)工程生态与经济协调发展目标的两条途径,这就是:政策调动;产业化发展。     

Mangrove community recovery potential after catastrophic disturbances in Bangladesh

The objective of this study was to compare the variation in the soil seed banks and the aboveground vegetation in relation to three habitats, i.e., swamp forests, grassland and sand dunes within the Sundarbans mangrove forests of Bangladesh. We collected vegetation data (species and their percentage cover) by using quadrat sampling: 10 m × 10 m for swamp forests and 5 m × 5 m for grassland and sand dunes. We estimated the density of viable seeds of species in the seed bank by counting germinants from soil cores in a germination chamber. Species richness and composition of both aboveground vegetation and the soil seed banks differed significantly among habitats. We identified a total of 23 species from the soil seed bank. Of these, two were true mangrove species and the remaining were non-mangrove species, including halophytic grasses, herbs and mangrove associate species. Our results confirm that mangrove species do not possess a persistent soil seed bank. The presence of high-density non-mangrove and associated mangrove species in the soil seed bank implies that after frequent catastrophic disturbances which limit incoming propagules from adjacent forest stand, large canopy gaps can easily become invaded by non-mangrove and mangrove associate species. This would result in the formation of a cover of non-mangrove species and cryptic ecological degradation in mangrove habitats. We suggest that forest managers should actively consider gap plantations with mangrove species in the large canopy gaps created after catastrophic disturbances to counteract the invasion of non-mangrove species and cryptic ecological degradation.     

Invasion and management of a woody plant, Lantana camara L., alters vegetation diversity within wet sclerophyll forest in southeastern Australia

Plant invasions of natural communities are commonly associated with reduced species diversity and altered ecosystem structure and function. This study investigated the effects of invasion and management of the woody shrub Lantana camara (lantana) in wet sclerophyll forest on the south-east coast of Australia. The effects of L. camara invasion and management on resident vegetation diversity and recruitment were determined as well as if invader management initiated community recovery. Vascular plant species richness, abundance and composition were surveyed and compared across L. camara invaded, non-invaded and managed sites following L. camara removal during a previous control event by land managers. Native tree juvenile and adult densities were compared between sites to investigate the potential effects of L. camara on species recruitment. Invasion of L. camara led to a reduction in species richness and compositions that diverged from non-invaded vegetation. Species richness was lower for fern, herb, tree and vine species, highlighting the pervasive threat of L. camara. For many common tree species, juvenile densities were lower within invaded sites than non-invaded sites, yet adult densities were similar across all invasion categories. This indicates that reduced species diversity is driven in part by recruitment limitation mechanisms, which may include allelopathy and resource competition, rather than displacement of adult vegetation. Management of L. camara initiated community recovery by increasing species richness, abundance and recruitment. While community composition following L. camara management diverged from non-invaded vegetation, vigorous tree and shrub recruitment signals that long-term community reinstatement will occur. However, secondary weed invasion occurred following L. camara control. Follow-up weed control may be necessary to prevent secondary plant invasion following invader management and facilitate long-term community recovery.     

哈尔滨地区引种石竹示范研究

石竹原产中国,分布很广。除华南较热地区外,几乎全国各地均有分布。喜阳、耐寒,耐干旱,忌涝,喜排水良好、肥沃沙质壤土。通过3年对这20种花卉的试验观察,总结出石竹在太阳岛地区的生态表现和适应性,并掌握其越冬技术和繁殖方法,为其在北方因林中的推广栽培应用提供试验和理论依据。     

桂花夏季扦插育苗技术研究

试验于2011年夏季进行了桂花不同基质(林地表土、炉渣土、农田土)、不同扦插方式(营养钵和田间苗床扦插)、插穗叶片不同处理(1片全叶、2片全叶、2片叶剪半)对比试验,结果表明:以林地表土和炉渣土扦插的生根率均较高,分别达95.5%和96.2%;营养钵和田间苗床扦插的生根率均较高,分别达95.0%和95.7%;插条叶片以留1片全叶和2片叶剪半的扦插生根率较高,分别达95.7%和95.3%。     

Spatio-temporal Variation of Distribution Patterns in Cunninghamia lanceolata Plantations

To aid in management of Cunninghamia lanceolata,the main timber species in Southern China,its variation of spatial distribution pattern was analyzed.Three permanent plots of C.lanceolata plantations with approximately the same site conditions,set by China continuous forest inventory in Shunchang,Fujian,were selected. C.lanceolata growth was divided into two stages: young trees(5 cm≤diameter at breast height (DBH)<10 cm) and mature trees(DBH≥10 cm). The DBH and coordinates of every tree(DBH≥5 cm) in the permanent plots were recorded in 2003 and 2008.The function L(r),improvement of Ripley’s K(r),the paircorrelation function g(r),and the uniform angle index(W_i) were used to analyze the spatio-temporal variation of spatial distribution patterns.The three permanent plots had mean uniform angle index(W) between 0.494-0.578 at low altitudes,0.465-0.477 at medium altitudes,and 0.426-0.601 at high altitudes.Results showed that altitude did not affect the spatial distribution pattern. The L(r ) and g(r) function curves of mature trees were generally lower than young trees’,i.e.tend to be more random or uniform distribution.So regardless of the initial distribution of young or mature trees,with the passage of time,there was a tendency for the aggregated distribution to change to a random distribution,and a random distribution to change to a uniform distribution.     

天水城区园林绿化现状与发展对策研究

天水是我国历史文化名城和优秀旅游城市，地处西北，干旱少雨，生态环境脆弱，城市园林绿化具有一定的特殊性。通过调查天水城区园林绿化现状和园林植物种类、分布、数量，分析其特点，提出了天水今后园林绿化与绿地系统建设的建议，以创造更加优美、自然、和谐的城市人居环境。