From sea to land: assessment of the bio-transport of phosphorus by penguins in Antarctica

In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Biovectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96×109–1.63×1010 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-free areas of the Antarctica.     

Poverty reduction, environmental protection and ecosystem services: A prospective theory for sustainable development

Poverty reduction and environmental protection are two global tasks for sustainable development.The study perspective has changed over time,from narrowly focusing on poverty reduction to comprehensively strengthening human-welfare.We reviewed key references targeting the theoretical content and practical approach relying on poverty,environment protection and ecosystem services.We discussed the contradicting views on the relationship of poverty and environmental degradation,and then illustrated the study progress of a cutting-age topic-ecosystem services which pave a way to address poverty reduction and environmental protection together.At last,we investigated essential factors that affect the development and environmental protection.Considering the evolution of the concept of poverty,we found that the environment has occupied an increasing proportion in the cognizance of poverty.The relationship between poverty and environmental degradation is regional uniqueness.In practical aspect,projects based on the management and valuation assessment of ecosystem services draw researchers′attention all over the world.The appropriate scale,essential economic incentives,morality,law and social equality are key factors affecting individuals′decisions which directly relate to the sustainable development.     

Governing agriculture-forest landscapes to achieve climate change mitigation

This introduction to the special section on “Governing Agriculture-Forest Landscapes to Achieve Climate Change Mitigation” reviews external interventions to improve forest conditions and reduce deforestation, and by extension, influence carbon storage in agriculture-forest landscapes. The review is based on a careful survey of 123 cases of project-based and policy interventions to influence land use and forest cover outcomes. We propose that outcomes of interventions can be explained in terms of rights, incentives, and technologies related to land use and apply this framework to examine 12 types of interventions in agriculture-forest landscapes. The analysis of the identified 123 cases raises concerns about consistency of data and comparability of cases. Our preliminary evidence suggests limited association between the stated objective of an intervention and its success. This evidence also suggests that smaller scale and effective enforcement may be positively associated with improved forest outcomes. But the effectiveness of interventions across different agriculture-forest landscapes varies and available evidence does not permit easy generalizations. The variable effects of interventions across different agriculture-forest landscapes point to the need to better understand the forms and functions of interventions and to problems associated with assessing their relative efficacy.     

Numerical Simulation of Nutrient and Phytoplankton Dynamics in Guangxi Coastal Bays,China

The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads and water quality responses, which is crucial for developing eutrophication control strategies, is not well studied. In this study, the riverine fluxes of nutrients were quan- tified and integrated with nutrient cycling and phytoplankton dynamics by using box models for Guangxi coastal bays. The model concepts and biogeochemical equations were the same; while most model parameters were specific for each bay. The parameters were calibrated with seasonal observations during 2006--2007, and validated with yearly averaged measurements in 2009. The gen-eral features of nutrient and phytoplankton dynamics were reproduced, and the models were proved feasible under a wide range of bay conditions. Dissolved inorganic nitrogen was depleted during the spring algal bloom in Zhenzhu Bay and Fangcheng Bay with relatively less nutrient inputs. Phosphorus concentration was high in spring, which decreased then due to continuous phytoplankton consumption. Chlorophyll-a concentration reached its annual maximum in summer, but was the minimum in winter. Eutrophication was characterized by both an increase in nutrient concentrations and phytoplankton biomass in Lianzhou Bay. Either about 80% re-duction of nitrogen or 70% reduction of phosphorus was required to control the algal bloom in Lianzhou Bay. Defects of the models were discussed and suggestions to the environmental protection of Guangxi coastal bays were proposed.     

Reflections on Science–Stakeholder Interactions in Climate Change Adaptation Research within Swedish Forestry

Stakeholder engagement has become increasingly important in research programs focusing on climate change impact on ecosystem services. Communication between researchers and stakeholders, however, is often impaired by linguistic barriers, different priorities, and time constraints. This article examines the organizational aspects of science–stakeholder interactions, focusing on examples from the Swedish forestry sector. The study highlights the need articulated by the Swedish forestry sector for access to scientific knowledge, and we discuss how to present research findings in formats suitable to serve as decision support. Clear communication about common goals, expectations, resources, and time frames is needed in order to reduce the risk of stakeholder fatigue.     

Simulating the impacts of fishing on central and eastern tropical Pacific ecosystem using multispecies size-spectrum model

The size-spectrum model has been considered a useful tool for understanding the structures of marine ecosystems and examining management implications for fisheries. Based on Chinese tuna longline observer data from the central and eastern tropical Pacific Ocean and published data, we developed and calibrated a multispecies size-spectrum model of twenty common and commercially important species in this area. We then use the model to project the status of the species from 2016 to 2050 under five c...     

Construction and analysis of a coral reef trophic network for Qilianyu Islands,Xisha Islands

Qilianyu Islands coral reefs (QICR), located in the northeastern part of the South China Sea, has been affected by human activities and natural disturbance. To characterize the trophic structure, ecosystem properties and keystone species of this region, a food-web model for the QICR is developed using methods involving a mass-balance approach with Ecopath with Ecosim software. Trophic levels range from 1.00 for detritus and primary producers to 3.80 for chondrichthyes. The mean trophic transfer efficiency for the entire ecosystem is 13.15%, with 55% of total energy flow originating from primary producers. A mixed trophic impact analysis indicates that coral strongly impacts most components of this ecosystem. A comparison of our QICR model with that for other coral reef ecosystems suggests that the QICR ecosystem is immature and/or is degraded.     

Savanna grass nitrogen to phosphorous ratio estimation using field spectroscopy and the potential for estimation with imaging spectroscopy

Determining the foliar N:P ratio provides a tool for understanding nutrient limitation on plant production and consequently for the feeding patterns of herbivores. In order to understand the nutrient limitation at landscape scale, remote sensing techniques offer that opportunity. The objective of this study is to investigate the utility of field spectroscopy and a potential of hyperspectral mapper (HyMap) spectra to estimate foliar N:P ratio. Field spectral measurements were undertaken, and grass samples were collected for foliar N and P extraction. The foliar N:P ratio prediction models were developed using partial least square regression (PLSR) with original spectra and transformed spectra for field and the resampled field spectra to HyMap. Spectral transformations included the continuum removal (CR), water removal (WR), first difference derivative (FD) and log transformation (Log(1/R)). The results showed that CR and WR spectra in combination with PLSR predicted foliar N:P ratio with higher accuracy as compared to FD and R, using field spectra. For HyMap spectral analysis, addition to CR and WR, FD achieved higher estimation accuracy. The performance of FD, CR and WR spectra were attributed to their ability to minimize sensor and water effects on the fresh leaf spectra, respectively. The study demonstrated a potential to predict foliar N:P ratio using field and HyMap simulated spectra and shortwave infrared (SWIR) found to be highly sensitive to foliar N:P ratio. The study recommends the prediction of foliar N:P ratio at landscape level using airborne hyperspectral data and could be used by the resource managers, park managers, farmers and ecologists to understand the feeding patterns, resource selection and distribution of herbivores (i.e. wild and livestock).     

甘肃敦煌西湖荒漠-湿地生态系统优势植物种群分布格局及种间关联性

基于25个样地、375个样方和150条样线的调查资料,采用扩散系数(C)、负二项参数(K)、平均拥挤度(m*)、丛生指标(D、聚块性指标(PI)、Green指数(GI)、Cassie指标(GA)和Moristia指数(Ⅰδ)等8个指标以及方差比率(VR)法,对甘肃敦煌西湖荒漠-湿地生态系统优势植物种群的空间分布格局、聚集强度和种间总体关联性进行了研究.结果表明:①研究区8种优势种群均为聚集分布(p＜0.01).其中,多枝柽柳群落、多枝柽柳沙包群落和胡杨群落均具有较高聚集程度,而疏叶骆驼刺群落和芦苇群落均具有较低聚集程度.②研究区优势种群中灌(乔)木层均为聚集分布(p＜0.05).③研究区优势种群在各海拔梯度上均为聚集分布(p＜0.05).随海拔梯度的增加,种群聚集强度增加,且种群聚集程度变化较为平缓.④研究区植物群落中,灌(乔)木层主要种群的种间联结表现为显著的正关联,乔灌草和草本层的主要种群的种间联结表现为显著的负关联.应用2×2联列表x2统计量、联结系数(AC)和共同出现百分率(PC)等方法,综合分析了敦煌西湖主要种群的种间联结显著性和关联强度.结果表明:研究区大多数种群种间关联程度不显著(p＞0.05),不关联的种对数明显要多于显著关联种对数,显著负关联的种对数多于正关,说明种群对生境和资源要求不一样,与总体种间相关性检验的方差比率VR值的结果一致,群落中优势物种处于不稳定阶段.