树林中

有一天，我去树林采树叶。走进树林时，我惊呆了：红红的枫叶像一只只小手在跟我招手，黄黄的银杏树叶像一把把小扇子，绿中泛黄的梧桐树叶也在秋风中不停地摇晃……

树林中的那一对(微型小说）

男孩常常到这个小树林里读书,绿绿的草地,蓝蓝的天空,树上的小鸟在唱歌,于是男孩便很高兴的样子。

Mangrove Flora of the World

The species composition and characteristics of mangrove flora in the world were reviewed and discussed. The results suggested that the world's mangrove plants have 84 species (including 12 varieties) in 24 genera and 16 families. Of which, true mangrove plants have 70 species (including 12 varieties) in 16 genera and 11 families, and semi-mangrove plants 14 species in eight genera and five families. The Eastern Group has 74 species (including 12 varieties) in 18 genera and 14 families, characterized by the genera Aegiceras, Osbornia, Aegialitis, Bruguiera, Ceriops, Kandelia, Scyphiphora and Nypa etc. The Western Group has only 10 species in six genera and five families, characterized by the endemic one-species family, Pelliceraceae, and the genus Laguncularia. The mangrove flora of China is composed of 26 species (including one variety) in 15 genera and 12 families, four of which are endemic. Hainan is most rich in mangrove species, making up about 96.2% of the Chinese total; Guangdong ranks second, making up about 42.3%. It has been demonstrated that Rhizophora stylosa was mistaken for R. mucronata in Taiwan by previous authors.

Dynamic change of arborous species diversity in natural secondary forests after selective cutting on the north slope of Changbai Mountain, Northeast China

The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration period of 28 years were studied. The results showed that the arborous species richness (S) had little change and kept the range of 18-22 all along, the Simpson index (D) of the secondary layer and regeneration layer and whole stand had similar trends of change, but that of the canopy layer descended slowly in initial 15 years and had little change later, and the change of diversity index was not obvious and the Shannon-Wiener index (H? fluctuated in a very small scopes (H±10%).

Biomass Carbon Sequestration by Planted Forests in China

The planted forest area and carbon sequestration have increased significantly in China,because of large-scale reforestation and afforestation in the past decades.In this study,we developed an age-based volume-to-biomass method to estimate the carbon storage by planted forests in China in the period of 1973-2003 based on the data from 1209 field plots and national forest inventories.The results show that the total carbon storage of planted forests was 0.7743 Pg C in 1999-2003,increased by 3.08 times since the early 1970s.The carbon density of planted forests varied from 10.6594 Mg/ha to 23.9760 Mg/ha and increased by 13.3166 Mg/ha from 1973-1976 to 1999-2003.Since the early 1970s,the planted forests in China have been always a carbon sink,and the annual rate of carbon sequestration was 0.0217 Pg C/yr.The carbon storage and densities of planted forests varied greatly in space and time.The carbon storage of Middle South China was in the lead in all regions,which accounted for 23%-36% of national carbon storage.While higher C densities (from 17.79 Mg/ha to 26.05 Mg/ha) were usually found in Northeast China.The planted forests in China potentially have a high carbon sequestration since a large part of them are becoming mature and afforestation continues to grow.

Secondary Production of Macrobenthos in Mangrove Area of Tong'an Bay,China

Studies on secondary production lead to a better understanding of the functions of the macrobenthic ecosystem.Basedon the macrobenthic data obtained at 6 sampling stations from April 2006 to January 2007,Brey's(1990)empirical formula wasapplied to calculate the secondary production of macrobenthos in the mangrove area of Tong'an Bay.The results showed that themean annual secondary production of macrobenthos was 13.24 gAFDWm-2-a-1.The mean secondary production in the mangrovehabitat was 12.22 gAFDWm-2-a-1,lower than that in the non-mangrove habitat,which was 15.29 gAFDWm-2-a-1.Two possible rea-sons existed for this difference.First,mollusk and crustacean,which contribute more to the secondary production,probably benefitfrom longer inundation period in the non-mangrove habitat.Second,the higher organic matter in the mangrove habitat results in hy-poxia in the bottom sediment,which may decrease the secondary production.The annual mean production-to-biomass(P/B)ratio inTong'an Bay was 1.17,with a ratio of 1.27 in the mangrove habitat and 0.96 in the non-mangrove habitat,which was coincident withthe much higher density of Limnodriloides sp.and Corophium sp.in the mangrove habitat than in the non-mangrove habitat.Themaximum secondary production and P/B ratio of macrobenthos both appeared at sampling station FL2 in April,2006(namelyApril-FL2)with values of 31.38 gAFDWm-2-a-1and 2.20,respectively.The macrobenthic secondary production in Tong'an Bay islower than those in other intertidal studies except that in Haitan Strait,the reason being the different sediment properties.The P/Bratio in Tong'an Bay was the lowest due to the high proportion of crustaceans in the macrobenthic community.

Contribution of Root Respiration to Total Soil Respiration in a Betula ermanii-Dark Coniferous Forest Ecotone of the Changbai Mountains, China

Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evaluate the seasonal variations of soil respiration, to assess the effect of soil temperature and water content on soil respiration, and to estimate the relative contributions of root respiration to the total soil respiration. PVC cylinders in each of 5 forest types of a B. ermanii-dark coniferous forest ecotone were used to measure soil respirations both inside and outside of the cylinders. The contribution of roots to the total soil respiration rates ranged from 12.5% to 54.6%. The mean contribution of roots for the different plots varied with the season, increasing from 32.5% on June 26 to 36.6% on August 3 and to 41.8% on October 14. In addition, there existed a significant (P < 0.01) logarithmic relationship between total soil respiration rate and soil temperature at 5 cm soil depth. Also, a similar trend was observed for the soil respiration and soil water content at the surface (0-5 cm) during the same period of time.

Low net primary productivity of dominant tree species in a karst forest, southwestern China： first evidences from tree ring width and girth increment

Aboveground net primary productivity(ANPP)of two dominant species, one deciduous tree(Platycarya strobilacea) and one evergreen tree(Machilus cavaleriei),was estimated based on the tree-ring width and the girth increment as well as allometric functions in a karst evergreen and deciduous broadleaved mixed forest in central Guizhou Province, southwestern China. Results showed that the ANPP increased from 1961 to 2015, especially during the last 20–30 years, but with strong variations. The deciduous tree had higher ANPP than the evergreen tree according to two kinds of estimates by the tree ring and girth increment. The averaged ANPP for these two mature trees was 2.27 kg/individual/year, ca. 8 t/ha/year considering the normal stand density. Such karst forest productivity was lower than the natural subtropical forests in China and in the world.

树林中的老房子

这天，大牙鼠和小白兔、小刺猬来到树林中的老房子里玩捉迷藏游戏。平时大人们总不让他们来这里玩，大人们说老房子里原来住着一个坏巫婆，她还抓走了小山羊。但他们几个天不怕地不怕，偷偷地跑到这里来玩耍……

Impacts of reforestation on woody species composition,species diversity and community structure in dry-hot valley of the Jinsha River,southwestern China

To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with adjacent wastelands,natural shrub grassland and a natural forest as references.Species importance value,species richness,species heterogeneity and Sorenson similarity index between plantations and the natural forest were analyzed.Results indicated that compared to wastelands and natural shrub grassland,reforestation improved species diversity and community structure,and more forest woody species found suitable habitats in plantations.Species diversity in understory of plantations and Sorenson similarity index were significantly negatively correlated with stem density in mature plantations(26-31 years old).Higher species diversity and Sorenson similarity index existed in mature sparse plantations due to lower stem density and more tree species planted initially.In contrast,reference natural forest,with species heterogeneity of 2.28 for shrub layer,showed the highest species diversity.It would take a long time for species composition and diversity to recover through reforestation in a dry-hot valley.Therefore,it was essential to protect remnant natural forests strictly and reforest with suitable management such as lower stem density and increasing genetic diversity of trees planted.

Two New Free-Living Marine Nematode Species of the Genus Anoplostoma(Anoplostomatidae) from the Mangrove Habitats of Xiamen Bay,East China Sea

Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.

Sedimentary Records of Mangrove Evolution During the Past one Hundred Years Based on Stable Carbon Isotope and Pollen Evidences in Maowei, SW China

Mangroves accumulate sedimentary sequences, where cores can provide historical records of mangrove evolution with past climate change and human activity. The study traced the history of mangrove evolution during the past one hundred years in a mangrove swamp of Maowei Sea, SW China. The sedimentation rates(0.38-0.95 cm yr^(-1)) were calculated on the basis of ln(^(210)Pb_(xs)/Al) and mass depth in the core sediments. Chemical tracers, such as δ^(13)C_(org) and C:N values, were utilized to trace the contribution of mangrove-derived organic matter using a ternary mixing model. Because of potential diagenetic alteration and / or overlap in the isotopic signatures of different components, simultaneous use of mangrove pollen diagrams can help to supplement some of these limitations. Combined with mangrove pollen, mangrove evolution was reconstructed and could be divided into three stages: flourishment(1886-1905 AD), slight degradation(1905-1949 AD) and rapid degradation period(1949-2007 AD), which was consistent with previous reports. The reclamation of mangrove swamps to shrimp ponds was the major reason for rapid degradation of mangrove ecosystems in recent years, rather than climate change in the region.

Some conifers from Aptian in Yanbian area of Jilin, Northeast China

Some well-preserved conifer leafy shoots and female cones from the Lower Cretaceous Changcai For- mation near Fudong of Helong, eastern Jilin, Northeast China are studied. Based on gross morphological and cuticular study, a new species, Elatides helongensis Sun et Zhao （ sp. nov. ） is described systematically. The new species is characterized by persistent, linear or slightly falcate leaves with obtusely acute apex, attached helically on the shoots. Female cones of the new species are terminal and oval, composed of persistent helically- arranged rhomboidal scales and erect seeds. One erect seed is growing on each scale. Leaf cuticles are hyposto- matic. Monocylic stomata are ellipse, composed of 2 sunken guard ceils and 4-8 subsidiary cells. Moreover, the cuticles of a young female cone of Pityostrobus yingchengensis Yang are described for the first time.

Bacterial Wilt and Boron Deficiency Stress:A New Disorder in Eucalypt Plantations in South China

This paper reports on a new disorder that first appeared in eucalypt plantations in south China in2003. The plantations were destructively sampled near Leizhou, Yanxi, Kaiping and Gaoyao in September toDecember 2003. Whilst some 5% of 0.5 to 1.5 year-old Eucalyptus urophylla trees declined rapidly andexhibited symptoms of wilting, the majority of the affected trees declined slowly and exhibited two foliarsymptoms. Young leaves initially developed an interveinal chlorosis extending from the leaf margin inwardsto the midrib. Most leaves then developed pockets of necrotic tissue that became bleached but typically hadbrown margins. The former symptoms have been recognised as being caused by limited boron supply in soil,but the latter symptoms have not been previously observed in eucalypts in China. Inorganic analysisshowed that the leaves with the latter symptoms had deficient B concentrations whereas the leaves fromhealthy trees had adequate B concentrations. Bacterial wilt, Ralstonia solanacearum, was present at all siteswhere foliar symptoms and tree death were present. The root system of all trees with foliar chlorosis andnecrosis had signs of infection in some roots and attrition of lateral roots. The trunk and branches of therecently died trees and the trees with advanced leaf drop had discoloured xylem, which on cutting, oozedbacterial slime. Possible relationships between root damage caused by abiotic (e.g. typhoons, root damagefrom hand weeding) and biotic factors and reduced B uptake are discussed. Recommendations are made forreducing bacterial wilt disease and improving B management in fast-growing short-rotation eucalypt plantations.

Estimating Change in Sedimentary Organic Carbon Content During Mangrove Restoration in Southern China Using Carbon Isotopic Measurements

Based on total carbon(C) and C isotopes in sediment cores,sedimentary organic carbon(SOC) was quantified in three types of mangrove sites(barren flat sites without mangroves,mangrove plantations,and natural mangrove forests),which were considered to represent a continuum from least restored to most restored sites in southern China.SOC densities in the barren sites,plantations,and natural forests were 90,170 and 288 Mg ha 1,respectively.We inferred that mangrove restoration increased SOC accumulation in coastal areas.At 0-70 cm depth,SOC δ 13 C values in both mangrove sites ranged from 27.37‰ to 23.07‰ and exhibited gradual enrichment with depth.In contrast,the values in the barren flat sites remained around 22.19‰ and fluctuated slightly with depth.At 0-60 cm,the 14 C ages of the SOC in the barren flat site,the natural mangrove site,and the artificial mangrove site ranged from 1 397 to 2 608,255 to 2 453,and 391 to 2 512 years BP,respectively.In both types of mangrove sites but not in the barren flat sites,the enrichment of δ 13 C with depth was related to increases in SOC decay and SOC age with depth.According to analysis of 14 C age,much of the mangrove-derived C was transported and stored at 0-60 cm depth under anaerobic conditions in both mangrove sites.The sediments of mangrove forests in southern China sequester large quantities of SOC during mangrove restoration.

Study of Priority Area Selection and Evaluation for Afforestation and Reforestation Project under CDM in China

This paper gives an expatiation on significance and specific requirements of developing afforestation and reforestation project under CDM in Kyoto Protocol. According to the international rules and the current forestry development situation in China, the priority area for CDM afforestation and reforestation （CDM A/R） project is finally found after scientific selection and assessment on indicators, including the non-forestland area in 1990, growth rate of tree, afforestation cost, biodiversity and community development. The outcome from the study provides a solid basis for finding and implementing CDM A/R carbon sequestration projects in China. The study also puts forward suggestions on the strategy to develop and manage CDM A/R projects in China