Greenhouse gas emissions and net carbon sequestration of the Beijing-Tianjin Sand Source Control Project in China

As a major driving element of the structure and function of arid and semiarid ecosystems, rainfall is the essential factor limiting plant biological processes. To clarify the characteristics of transpiration and responses to summer rainfall, sap flow density (F d) of Pinus tabulaeformis and Hippophae rhamnoides was monitored using thermal dissipation probes. In addition, midday leaf water potential (ψm) and leaf stomatal conductance (G s) were also analyzed to determine water use strategies. The results indicated that the diurnal variation in the normalized F d values exhibited a single‐peak curve for P. tabulaeformis, while H. rhamnoides showed multiple peaks. The normalized F d for P. tabulaeformis remained relatively stable regardless of rainfall events. However, there was also a significant increase in the normalized F d for H. rhamnoides in response to rainfall in June and August (p < .05), although no significant differences were observed in July. The normalized F d values for P. tabulaeformis and H. rhamnoides fitted well with the derived variable of transpiration, an integrated index calculated from the vapor pressure deficit and solar radiation (R s), using an exponential saturation function. The differences in fitting coefficients suggested that H. rhamnoides showed more sensitivity to summer rainfall (p < .01) than P. tabulaeformis. Furthermore, during the study period, P. tabulaeformis reduced G s as soil water decreased, maintaining a relatively constant ψm; while H. rhamnoides allowed large fluctuations in ψm to maintain G s. Therefore, P. tabulaeformis and H. rhamnoides should be considered isohydric and anisohydric species, respectively. And more consideration should be taken for H. rhamnoides in the afforestation activities and the local plantation management under the context of the frequently seasonal drought in the loess hilly region.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.3639

Sap flow characteristics and responses to summer rainfall for Pinus tabulaeformis and Hippophae rhamnoides in the Loess hilly region of China.

Natural regeneration of tree species is important to the sustainability of native forest ecosystems in the temperate zone of north- east China. This study compared the densities and heights of seedlings and the diversities of shrubs and herbs on three sites of logging op- erations: log-skidding trails (LST), logging gaps (LG) and log landing sites (LLS). Sites undisturbed by logging gaps operations were sam- pled as control. The species, counts and height of tree seedlings and the species, counts, height and percentage coverage of shrubs and herbs were recorded in the field. The highest density and greatest height of regeneration trees were observed at LG and LST. The effects of LST on the densities of broadleaved trees were greater than those of coniferous trees. The difference in seedling density between LLS and control was significant (p=0.05). There was no significant difference in average seedling height for all the tree species between the disturbed sites and control. There were more shrub and herb species at the disturbed sites than at control. The diversity of understory plants at LG was the highest among all the sites. LST and LLS were different in shrub diversity, so were LLS and control. Both LG and LLS were different from control in herb diversity. Active measures need to be taken on the operation sites to protect the coniferous trees and the diversities of under- story plants for sustaining the structure and composition of the broadleaved-Korean pine mixed forest on Changbai Mountain of China. Since different operation sites have different effects on different tree species, site-dependent actions must be taken to assure the regeneration of ecologically important tree species.

An impacts of logging operations on understory plants for the broadleaved/Korean pine mixed forest on Changbai Mountain, China

To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national accounts (SNA) and data from the latest forest resources inventory in China. The study calculated the value of forest carbon stocks at a total of RMB 817.13 × 109 yuan in 2003 and RMB 839.93 × 109 yuan in 2008, with an average annual increase of 0.55 % from an increase in physical carbon sinks. The total value of forest carbon sinks in 2003 and 2008 was RMB 26.73 × 109 yuan and RMB 29.77 × 109 yuan, respectively, with an average annual growth of 2.18 %. From 2003 to 2008, both stock and flow value of forest carbon sinks increased, but the total net flow value of carbon sinks decreased. The growth rate for the environmentally adjusted Gross Domestic Product (eaGDP) for China’s forest carbon sinks was 17.23 %, outstripping the average growth rate of 9.5 % for the GDP during the same period. The study also indicates that China’s forest carbon sinks affects the GDP in the range of 0.25–0.26 %, and its economic potential is not relatively huge.

Valuation of forest carbon sinks in China within the framework of the system of national accounts

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%).

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

Leakage has been one of the issues in the negotiation of forestry project activities under the clean development mechanism (CDM). Based on the definition and types of leakage and on the investigation of case studies on CDM forestry project activities, we analyzed the potential leakages of forest conservation and afforestation project activities from the points of causes, mechanism and ranges that leakage occurs. A decision tree was designed for the determination of leakage and methodology for monitoring leakage was discussed. Some suggestions for understanding and managing leakage of forestry project activities were put forwards. As CDM forestry project activities have been attracting more and more attentions in China, we hope our analyses could benefit those who are preparing or planning to do CDM forestry project activities in China on how to address and manage leakage issues.

Analyses on Leakage Issues of Forestry Sequestration Project

A comparison was made on the plant divenity of Pinus koraiensis forest after selective cutting and Betula platyplla secondary forest formed after clear cutting in the Pkoraiensis forests in Changbai Mountain forest region in China The results show that the divenity of the whole community and undergrowth of B platyphyllasecondary forest are higher than that of any type of P koraiensis forests The divenity of the whole community and tree layer of P korairensis virgin forest with slight- selective cutting are the highest among all P koraiensis forests, which is the result of the forest adapting long term succession and species adaptation Because B platyphylla forest is in the second succession stage, more shade- tolerant tne species had colonized the community Besides, solar radiation is the B platyphylla forest is better so that the undergrowth developed well, and the diversity of woody plant is very high At last the relationships between diversity and evenness, haibtat of the communities are analysed

Plant diversity of pinus koraiensis forests under disturbance in changbai mountains of china

The risks that lead to re-release of the net anthropogenic greenhouse gases removal by sinks for CDM forestry project are analyzed from the point of naturally-occurring and human-induced,and the risks from re-release of the net anthropogenic greenhouse gases removal by sinks in the crediting period are analyzed form the point of economics and environment.Finally,Some management strategies that reduce and respond to these risks are put forward.

Analyses on Non-Permanence Issues of CDM Forestry Project

In the same or semblable planting sites, in the seasons of summer and autumn, the parameters of hydraulic architecture of four young Pinus tabulaeformis were measured in improved flushing method. The parameters were hydraulic conductivity (K h, gm·MPa -1min -1, the weight of oxalic acid solution through the xylem per minute and per pressure gradient),leaf specific conductivity(LSC, gm·MPa -1min -1g -1, hydraulic conductivity per dry weight of supplied leaves),specific conductivity(K s, gm·MPa -1min -1cm -2, hydraulic conductivity per transverse sapwood area),and Huber value(HV, cm 2·g -1, transverse sapwood area per dry weight of supplied leaves). The study indicated hydraulic conductivity was influenced not only by the stem diameter, but also by the location of stem.The hydraulic conductivity of restriction area (namely in the base of the fork) was evidently lower than that of non-restriction area. Meanwhile, every parameter of hydraulic architecture was influenced in a way by the relative ramification rate, crown layer and ramification direction. To some extent, these characters expounded the biological trait of Pinus tabulaeformis, and determined its ecology strategy of drought resistance.

Bfu Beijing

Papers

Analyses on Leakage Issues of Forestry Sequestration Project

Plant diversity of pinus koraiensis forests under disturbance in changbai mountains of china

Analyses on Non-Permanence Issues of CDM Forestry Project

The hydraulic architecture character of pinus tabulaeformis