Trend assessment of changing climate patterns over the major agro-climatic zones of Sindh and Punjab

The agriculture sector, due to its significant dependence on climate patterns and water availability, is highly vulnerable to changing climate patterns. Pakistan is an agrarian economy with 30% of its land area under cultivation and 93% of its water resources being utilized for agricultural production. Therefore, the changing climate patterns may adversely affect the agriculture and water resources of the country. This study was conducted to assess the climate variations over the major agro-climatic zones of Sindh and Punjab, which serve as an important hub for the production of major food and cash crops in Pakistan. For this purpose, the climate data of 21 stations were analyzed using the Mann–Kendall test and Sen's slope estimator method for the period 1990–2022. The results obtained from the analysis revealed that, in Sindh, the mean annual temperature rose by ~0.1 to 1.4°C, with ~0.1 to 1.2°C in cotton-wheat Sindh and 0.8 to 1.4°C in rice-other Sindh during the study period. Similarly, in Punjab, the mean annual temperature increased by ~0.1 to 1.0°C, with 0.6 to 0.9°C in cotton-wheat Punjab and 0.2 to 0.6°C in rainfed Punjab. Seasonally, warming was found to be highest during the spring season. The precipitation analysis showed a rising annual precipitation trend in Sindh (+30 to +60 mm) and Punjab (+100 to 300 mm), while the monsoon precipitation increased by ~50 to 200 mm. For winter precipitation, an upward trend was found in mixed Punjab, while the remaining stations showed a declining pattern. Conclusively, the warming temperatures as found in the analysis may result in increased irrigation requirements, soil moisture desiccation, and wilting of crops, ultimately leading to low crop yield and threatening the livelihoods of local farmers. On the other hand, the increasing precipitation may favor national agriculture in terms of less freshwater withdrawals. However, it may also result in increased rainfall-induced floods inundating the crop fields and causing water logging and soil salinization. The study outcomes comprehensively highlighted the prevailing climate trends over the important agro-climatic zones of Pakistan, which may aid in devising an effective climate change adaptation and mitigation strategy to ensure the state of water and food security in the country

Utilisation of analogous climate locations to produce resilient biodiversity plantings for infrastructure developments

Developers have an obligation to biodiversity when considering the impact their development may have on the environment, with some choosing to go beyond the legal requirement for planning consent. Climate change projections over the 21st century indicate a climate warming and thus the species selected for habitat creation need to be able to withstand the pressures associated with these forecasts. A process is therefore required to identify resilient plantings for sites subject to climate change. Local government ecologists were consulted on their views on the use of plants of non-native provenance or how they consider resilience to climate change as part of their planting recommendations. There are mixed attitudes towards non-native species, but with studies already showing the impact climate change is having on biodiversity, action needs to be taken to limit further biodiversity loss, particularly given the heavily fragmented landscape preventing natural migration. A methodology has been developed to provide planners and developers with recommendations for plant species that are currently adapted to the climate the UK will experience in the future. A climate matching technique, that employs a GIS, allows the identification of European locations that currently experience the predicted level of climate change at a given UK location. Once an appropriate location has been selected, the plant species present in this area are then investigated for suitability for planting in the UK. The methodology was trialled at one site, Eastern Quarry in Kent, and suitable climate matched locations included areas in north-western France. Through the acquisition of plant species data via site visits and online published material, a species list was created, which considered original habitat design, but with added resilience to climate change

Agroforestry Opportunities for Enhancing Resilience to Climate Change in Rainfed Areas,

Not AvailableAgroforestry provides a unique opportunity to achieve the objectives of enhancing the productivity and improving the soil quality. Tree systems can also play an important role towards adapting to the climate variability and important carbon sinks which helps to decrease the pressure on natural forests. Realizing the importance of the agroforestry in meeting the twin objectives of mitigation and adaptation to climate change as well as making rainfed agriculture more climate resilient, the ICAR-CRIDA has taken up the challenge in pursuance of National Agroforestry Policy 2014, in preparing a book on Agroforestry Opportunities for Enhancing Resilience to Climate Change in Rainfed Areas at ICAR-CRIDA to sharpen the skills of all stakeholders at national, state and district level in rainfed areas to increase agricultural productivity in response to climate changeNot Availabl

Nutrient Cycling in Forest Ecosystems

The long-term productivity of forest ecosystems depends on the cycling of nutrients. The effect of carbon dioxide fertilization on forest productivity may ultimately be limited by the rate of nutrient cycling. Contemporary and future disturbances such as climatic warming, N-deposition, deforestation, short rotation sylviculture, fire (both wild and controlled), and the invasion of exotic species all place strains on the integrity of ecosystem nutrient cycling. Global differences in climate, soils, and species make it difficult to extrapolate even a single important study worldwide. Despite advances in the understanding of nutrient cycling and carbon production in forests, many questions remain. The chapters in this volume reflect many contemporary research priorities. The thirteen studies in this volume are arranged in the following subject groups: • N and P resorption from foliage worldwide, along chronosequences and along elevation gradients; • Litter production and decomposition; • N and P stoichiometry as affected by N deposition, geographic gradients, species changes, and ecosystem restoration; • Effects of N and P addition on understory biomass, litter, and soil; • Effects of burning on soil nutrients; • Effects of N addition on soil fauna

Treeline dynamics: Pattern and process at multiple spatial scales

The primary hypothesis of treeline formation, low growing season temperature limitation of growth, predicts that treeline position will track climatic changes. These hypotheses were generated from broad treeline patterns, which may overlook critical local variability. To assess the hypothesis that all treelines are limited by low temperature and will respond in kind, treeline response over the last 100 years was evaluated at 166 treeline sites in a meta-analysis. Treeline advance was variable and not related to climate warming in the way expected. Treelines that experienced strong winter warming were more likely to have advanced and treelines with a diffuse form were more likely to have advanced than those with an abrupt, Krummholz or island form. Diffuse treelines may be more responsive to warming because they are more strongly growth limited, whereas other treeline forms may be subject to additional constraints. The results suggest that mechanisms other than growing season temperature, such as winter dieback and recruitment failure, may also determine treeline position and dynamics. As treeline responses worldwide confirm a close link between form and dynamics, variability in treeline response may be explained by identifying the mechanisms controlling treeline form. The varying dominance of three mechanisms affecting tree performance - growth limitation, seedling mortality and dieback – modified by species traits, local climatic conditions, stressors and neighbour interactions is proposed to result in different treeline forms and the expected response of treelines to climatic change. The proposed mechanisms controlling treeline form and expected responses to climate warming were subsequently tested at the abrupt Nothofagus treeline in New Zealand. The role of growth, mortality (across all size classes) and recruitment in controlling treeline dynamics were evaluated using long-term data collected along seven abrupt Nothofagus treeline transects in the South Island, New Zealand. Demographic parameters were modelled over two periods, 1991-2002 and 2002-2008 within a Bayesian framework. Stem number increased above treeline over the 15-year study duration but stem distribution above treeline did not change; 90% of all stems and of new recruits occurred within 10 m of the treeline edge. Modelled growth, mortality and recruitment rates varied by period, transect and stem size. Results do not provide clear evidence of treeline advance but do indicate that recruitment is ultimately limiting advance. The causes of recruitment limitation were then tested through transplanted Nothofagus solandri var. cliffortioides and Pinus contorta seedlings along a 200 m vertical transect starting 50 m below treeline and with passive warming. Survival and growth of seedlings transplanted 150 m beyond the Nothofagus treeline did not decrease with distance from the treeline edge or improve with passive warming (repeated measures ANOVA, p > 0.05). Survival varied by species; P. contorta exhibited a greater overall probability of mortality than N. solandri. Relative growth rates did not significantly differ between species but pine exhibited a net increase in height whereas N. solandri exhibited a net decrease in height. At the seedling stage, low temperature is not limiting and N. solandri does not appear to be less well adapted to treeline conditions than northern hemisphere conifer species. The role of facilitation was subsequently tested by removing vegetation around N. solandri seedlings. Vegetation removal negatively affected N. solandri seedling survival. No effect of passive warming was observed. The results confirm that N. solandri can survive beyond their present limit but that growth and survival are limited to facilitative microsites. Treeline advance at the Nothofagus treeline in New Zealand is proposed to be limited by germination ability in dense vegetation and intolerance in the early life stages to sky exposure. Positive feedback, whereby established trees create ideal microsites for germination and seedling establishment, is proposed to be critical in determining recruitment patterns and the relative inertia to climatic change observed at the treeline. The results overall indicate that, globally, treeline response to climate change will be highly variable and not necessarily directly related to climate warming. Treeline form is a good indicator of the mechanisms controlling treeline dynamics and the potential response by treeline to climatic change

Application of Thermal and Phenological Land Surface Parameters for Improving Ecological Niche Models of Betula utilis in the Himalayan Region

Abstract: Modelling ecological niches across vast distribution ranges in remote, high mountain regions like the Himalayas faces several data limitations, in particular nonavailability of species occurrence data and fine-scale environmental information of sufficiently high quality. Remotely sensed data provide key advantages such as frequent, complete, and long-term observations of land surface parameters with full spatial coverage. The objective of this study is to evaluate modelled climate data as well as remotely sensed data for modelling the ecological niche of Betula utilis in the subalpine and alpine belts of the Himalayan region covering the entire Himalayan arc. Using generalized linear models (GLM), we aim at testing factors controlling the species distribution under current climate conditions. We evaluate the additional predictive capacity of remotely sensed variables, namely remotely sensed topography and vegetation phenology data (phenological traits), as well as the capability to substitute bioclimatic variables from downscaled numerical models by remotely sensed annual land surface temperature parameters. The best performing model utilized bioclimatic variables, topography, and phenological traits, and explained over 69% of variance, while models exclusively based on remotely sensed data reached 65% of explained variance. In summary, models based on bioclimatic variables and topography combined with phenological traits led to a refined prediction of the current niche of B. utilis, whereas models using solely climate data consistently resulted in overpredictions. Our results suggest that remotely sensed phenological traits can be applied beneficially as supplements to improve model accuracy and to refine the prediction of the species niche. We conclude that the combination of remotely sensed land surface temperature parameters is promising, in particular in regions where sufficient fine-scale climate data are not available

Forests and Society - Responding to Global Drivers of Change

Forests and Society --Responding to Global Drivers of Chang