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1.
Understanding people’s willingness to participate in projects and programmes of payments for ecosystem services (PES) has not been a key analytical concern of the scholarly literature around this new field of environmental policy and practice. This paper analyses participation in four communities benefiting from payments for biodiversity and carbon fixation in Mexico, and contrasts the results for each case with neighbouring communities that do not receive payments. We take a holistic approach that accounts for procedural rules, actors’ interactions, institutions and values, and individuals’ characteristics. We show that the nature of PES rules and the effectiveness of communication with government officers and NGOs influence resource managers’ ability and willingness to participate. We highlight community size, resource managers’ ability to diversify livelihood activities and local perspectives on the conservation of common forests, particularly sacred values and intergenerational concerns on forest conservation, as critical participation drivers. This analysis provides insights on why and how these new institutions may be attractive for some resource managers and permits to draw some recommendations for the future design of PES projects and programmes.  相似文献   
2.
Monsoon rainforests in the Darwin area occur as isolated patches ranging in size from 2 to 112 ha. Aerial photographic records over a 45 year period indicate a 60 per cent reduction in the cover of pre‐1945 rainforest. Urban development, cyclone damage, weed invasion and wildfire were identified as the major causes of this contraction. Urban development contributed 40 per cent of the total rainforest loss during this period. Rainforests occurring on dry substrates have been most affected by urban development. Cyclonic storm damage and indirect human affects such as weed invasion and anthropogenic fires continue to disturb the remaining rainforest patches. Although the largest expanses of rainforest presently occur within parks and reserves, providing adequate protection from further urban encroachment, smaller remnants occurring on vacant crown land are vulnerable to changes in land use. As well as the introduction of appropriate legislation, the control of fire and weeds should be given the highest priority by land managers to ensure the stability and long‐term maintenance of this remnant vegetation.  相似文献   
3.
Tree stem (>2 m tall) mortality was assessed following a late dry‐season wildfire across a seasonally flooded elevation gradient at Workshop Jungle, near Darwin, in the Northern Territory of Australia. For all species combined, dead stems had significantly smaller diameter at breast height (dbh) than living stems. Assessment of tree‐stem damage following a tropical cyclone at Cobourg Peninsula, NT, revealed that damaged stems had significantly greater dbh than undamaged stems for all tree species sampled across a boundary between monsoon rainforest and savanna. A greater proportion of stems were damaged by the cyclone than by the fire (28 per cent as against 18 per cent), although there were considerable between‐community differences in the proportion of damaged stems at the two sites. The fire caused little impact (<10 per cent) on total basal area of three different forest communities on the elevation gradient at Workshop Jungle. The cyclone was found to cause >50 per cent damage to total basal area of three different communities on Cobourg Peninsula. It is suggested that the combination of a cyclone followed by an intense fire in storm debris could potentially destroy a monsoon rainforest through its impact on all tree‐size classes. This may explain why some monsoon rainforests rapidly contracted following Cyclone Tracy that destroyed the city of Darwin on Christmas Day, 1974.  相似文献   
4.
为探讨热带季节雨林林冠上方大气稳定状态,为通量计算提供依据,利用2003-2004年热带季节雨林林冠上方的涡度相关法观测资料,对西双版纳热带季节雨林树冠上生态边界层内大气的稳定度频率分布进行了分析研究。计算了稳定度参数(z/L),并对大气稳定度类型进行了划分,分析了大气稳定状态的时间变化。结果表明:在热带季节雨林林冠上方的大气稳定度频率分布存在明显的日变化。昼间不稳定状态占优势,晚上以稳定状态为主;在早晨和下午稳定状态和不稳定状态频率分布易发生变化,导致中性的大气稳定状态更容易出现;而各大气稳定状态的频率分布年和季节变化相对较小,大气不稳定状态出现频率以雾凉季最高、干热季最低;稳定状态出现频率以干热季最高、雨季最低;中性状态出现频率以雨季最高、雾凉季最低。  相似文献   
5.
Early Pleistocene vegetation in upland southeastern Australia included diverse rainforests and sclerophyll forests, which alternated on precessional timescales. The nature and timing of transitions between these biomes, and the role of fire in maintaining or driving transitions between them, are uncertain. Here we present a high‐resolution pollen record from Stony Creek Basin, a small Early Pleistocene palaeolake in southeastern Australia. The pollen record documents a pattern of vegetation change, over ca. 10 ka at ca. 1590–1600 ka, between sclerophyll forests, dominated by Eucalyptus, Callitris (Cupressaceae) or Casuarinaceae, and rainforests dominated by either angiosperms or conifers of the family Podocarpaceae. Transitions between these biomes typically occurred within ca. 1–2 ka. The associated charcoal record suggests that greatest biomass combustion occurred when local vegetation was dominated by Eucalyptus, and the least biomass combustion occurred when local vegetation was dominated by Podocarpaceae. However, local fires burnt in both sclerophyll and angiosperm‐dominated rainforest vegetation, at least once every several centuries. Fire was very rare (less than about one fire per millennium) only when the local vegetation was rainforest dominated by Podocarpaceae. This suggests that fire was an irregular presence in both sclerophyll‐ and angiosperm‐dominated rainforest biomes during the late Neogene, though was largely absent in Podocarpaceae‐dominated rainforests. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
6.
Following the statistical analyses of long‐term rainfall‐runoff records from research basins in humid temperate latitudes, Hewlett and co‐workers extended the global challenge to disprove their findings that rainfall intensity was non‐significant. This paper responds to Hewlett's challenge as no preceding analyses have involved forested basins in a tropical cyclone‐prone area. Based on a 7 year rainfall‐runoff record, quickflow (QF), peak flow (QP) and quickflow response ratios (QRR) were regressed as dependent variables against rainfall parameters (intensity, Pi, amount, P), storm duration, D and antecedent flow, I. These data sets were categorised into total streamflow (Q) classes and stratified into three seasons, (monsoon, post‐monsoon and dry) for forested and cleared catchments. Where rainfall variable collinearity met acceptable levels, the addition of Pi to regression models including P, D, I contributed up to 9% and 66% of the respective variations in quickflow and peak flow. For the highest Q storm classes (monsoon), Pi alone accounted for up to 67% and 91% of the variation in QF and QP respectively and was the dominant influence on QP for all seasons. The very high rainfall intensities experienced in the monsoon season is a causal factor why these results differ from those of other research drainage basins. Surprisingly, Pi continued to have a significant influence on QF for dry season classes when less‐intense rainfall occurs. Further the results were similar for both catchments across all seasons. P was the dominant independent variable affecting QF above a threshold Q of 50 mm (monsoon), as rainfall contributes directly to saturation overland flow and return flow under saturated conditions. Further although QRR increased with increasing Q for each season, the regression results for that parameter were poor possibly due to the non‐linearity of the rainfall‐runoff relationship. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
7.
海南尖峰岭热带山地雨林作为典型的热带雨林生态系统之一,其长期的气候动态变化研究对全球变化研究有着重要的作用。采用1980--2005年海南尖峰岭森林生态系统国家野外科学观测研究站天池气象站地面常规气象观测资料,利用累积距平法和Mann—Kendall检验法分析了尖峰岭热带山地雨林区气候突变和气候异常。结果表明:近26a来,该区年平均气温、年平均地温、年平均最高最低气温、年积温和平均水汽压在1990年前后经历一次由低到高的突变,年平均风速在1993年经历由大到小的突变。在高强度ENSO事件发生的1998年,气温、地温均出现异常偏高,这些都表明该林区的森林气候变化正是对全球气候异常的明显响应过程。  相似文献   
8.
The watershed hydrologic model TOPMODEL was used to estimate interbasin groundwater flow (IGF) into a small lowland rainforest watershed in Costa Rica. IGF is a common hydrological process but often difficult to quantify. Four‐year simulations (2006–2009) using three different model approaches gave estimates of IGF that were very similar to each other (10.1, 10.2, and 9.8 m/year) and to an earlier estimate (10.0 m/year) based on 1998–2002 data from a budget study that did not use a hydrologic simulation model, providing confidence in the new estimates and suggesting each of the three model approaches is viable. Results show no significant temporal variation in IGF during 2006–2009 (or between this period and the earlier study from 1998–2002). Simulations of the 16 consecutive 3‐month periods in 2006–2009 gave 16 values of IGF rate with a mean (10.1 m/year, standard deviation = 0.6 m/year) very similar to the estimates above from the 4‐year simulations. This suggests the modified version of TOPMODEL can be used to model stream discharge and estimate IGF for sub‐annual time periods during which change in water storage is not necessarily equal to zero. Thus, simple watershed models may be used to estimate IGF based on even relatively short calibration periods, making such models useful tools in the study of this widespread hydrological process that affects water and chemical fluxes and budgets but is often difficult and costly to quantify. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
9.
西双版纳原始热带季节雨林净初级生产力   总被引:6,自引:1,他引:5  
研究了西双版纳原始热带季节雨林生物量增量、凋落量、叶虫食量和净初级生产量.该雨林年平均净初级生产量为25.764 t/hm2.a,其中各层次的净初级生产量分别为:乔木层23.972 t/hm2.a(占总净初级生产量的93.04 %)、灌木层0.749 t/hm2.a (占2.91 %)、木质藤本层0.431 t/hm2.a(占1.67 %)、草本层0.612 t/hm2.a(占2.38 %).乔木层净初级生产量分配为:凋落量11.566 t/hm2.a、叶虫食量0.694 t/hm2.a和生物量增量11.712 t/hm2.a.  相似文献   
10.
Many remaining areas of tropical rainforest in south‐east Asia are located on landscapes dominated by deep valleys and very steep slopes. Now that logging activities are extending into these steeplands, it is essential to understand how the natural rainforest system behaves if any kind of realistic assessment of the effects of such disturbance is to be made. This paper examines the hydrological behaviour of an undisturbed rainforest system on steep topography in the Temburong District of Brunei, north‐west Borneo. The physical and hydrological properties of the regolith material are generally typical of tropical residual soils. The regolith has a clay texture and a low dry bulk density beneath a superficial litter/organic horizon. The infiltration capacity of the surface soil was several hundred mm h−1. That of the exposed mineral subsoil was an order of magnitude less, similar to the saturated hydraulic conductivity (Ksat) of around 180 mm h−1 at a depth of 150 cm. There was no indication that Ksat reduced with depth except very near the bedrock interface. Soil tensions were measured using a two‐dimensional array of tensiometers on a 30° slope. During dry season conditions, infiltrating rain‐water contributes to soil moisture, and drying of the soil is dominated by transpiration losses. During wet season conditions, perched water tables quickly develop during heavy rainfall, giving rise to the rapid production of return flow in ephemeral channels. No infiltration excess or saturation overland flow was observed on hillslopes away from channel margins. Subsurface storm flow combined with return flow produce stream flow hydrographs with high peak discharges and very short lag times. Storm event runoff coefficients are estimated to be as high as 40%. It is concluded that the most distinctive feature of the hydrology of this ‘steepland rainforest’ is the extremely ‘flashy’ nature of the catchment runoff regime produced by the combination of thin but very permeable regolith on steep slopes. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
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