Abstract

Trees have been around for more than 370 million years, and today there are about 80 thousand species of them, occupying 3.5 billion hectares worldwide, including 250 million ha of commercial plantations. While forests can provide tremendous environmental, social, and economic benefits to nations, they also affect the hydrologic cycle in different ways. As the demand for water grows and local precipitation patterns change due to global warming, plantation forestry has encountered an increasing number of water-related conflicts worldwide. This document provides a country-by-country summary of the current state of knowledge on the relationship between forest management and water resources. Based on available research publications, the Editor-in-Chief of this document contacted local scientists from countries where the impact of forest management on water resources is an issue, inviting them to submit a chapter. Authors were instructed to use the following structure: 1. Introduction Present a brief history of the country's native forests and forest plantations, describing the past and current natural and plantation forest distribution (map, area, main species), as well as main products produced (timber, pulp, furniture, etc.). Characterize the country's water resources and main water uses, discussing the key water resource issues. Finally, describe the forest & water issues that are relevant in the country. 2. Literature review Write a brief review of water-related forest management studies. Include methods (e.g. paired watershed studies, precipitation/runoff relationship, water balance, hydrological modelling, sap flow meters, etc.) and results. End with a section on best management practices utilized or recommended by the country to increase water yield and/or improve water quality. 3. Politics Discuss key environmental regulations, laws, and policies related to forestry and water, and evaluate how research results have interacted with politics and vice versa, i.e. the creation of new regulations, either enforced by the law, or simply applied by the private sector, to improve water yield and water quality. Also, discuss the role of forest certification systems in managing water quantity and quality. 4. Climate change and the future of forestry & forest research Evaluate the effects of climate change in the country, especially on water resources, describing how the area occupied by forest plantations is increasing or decreasing, and where. End this section proposing future research and management practices that should be incorporated in the management of forest plantations to improve water quality and water yield. An excellent group from 13 nations, representing almost half the World’s population, submitted chapters (Argentina, Australia, Brazil, Chile, China, Republic of Congo, India, Malaysia, Peru, Romania, South Africa, Spain, and United States), making this document a relevant contribution to the current state of water and forestry-related issues, management, and policies worldwide. Differences in historical forest management, climate, vegetation types and socioeconomic conditions driving the use and management of forests mean that forest hydrology research results vary from nation to nation. This makes it difficult to generalise and extrapolate between countries and regions. What seems to be of greatest importance is the combination of watershed characteristics (size, slope and soils), current and prior land uses and local climates, especially the temporal distribution of annual precipitation and temperatures. In certain climates, for example parts of Australia, Brazil, Chile, China, India, South Africa, Spain and the USA, where natural grassland, shrublands or land previously cleared for agriculture is replaced with fast growing plantations, streamflows and groundwater recharge are often substantially reduced, potentially creating local conflicts between plantations and other water users. In South Africa and Australia, this has led to introduction of legislation to limit plantation developments in some areas. Conversely, reforestation of degraded agricultural land, especially where soils have been heavily compacted, can sometimes increase dry season streamflows by increasing infiltration rates and may also increase the soil’s water holding capacity as well as improving water quality. Consequently, flood mitigation is seen as an important role of forests in some countries. Whereas once forests were thought to bring rain, it is now well documented that at local scales of tens to tens of thousands of ha, replacement of shallow-rooted vegetation with forest usually reduces streamflow but may improve water quality. Permanent clearing of forest will increase streamflow in some regions, albeit often accompanied by reduced water quality. In the few parts of the world where fog drip is an important hydrologic input, forest clearing reduces water yield. At much larger scales, for example in the Amazon Basin in Brazil and Peru, extensive forests can cycle moisture between the land and the atmosphere so that large-scale clearing of natural forest may have detrimental effects on regional and national water cycles. In many countries, including Brazil, Chile, China, India, Malaysia, Peru, Romania, and Spain, deforestation and soil degradation have created water quality problems, which are now being addressed, or will need to be addressed through reforestation. In China, for example, extensive areas of highly erodible soils have been reforested. However there may be a trade-off between improved water quality through soil restoration and reduced water yield, unless rainfall occurs only during winter months, as is the Chilean case. Fire in forests can create concerns over water quality, and less commonly, water yield. In Australia, Spain and the USA, fire seasons are becoming longer and more extreme due in part to combinations of drier and warmer climate. Forest management to reduce fire risk and the associated detrimental effects of wildfire on water quality, is now an important consideration in these countries. Based on the information provided, the countries with the closest links between forest hydrology research and policy-making are Australia, Brazil, China, South Africa, and United States. However, in most of the reminding eight countries, research and political initiatives are rapidly advancing. Importantly, most countries have invested resources and research into climate change adaptations, including its effects on forests and water interactions. In many countries there is still a clear lack of connection between research results and effective forest management policies, a topic that urgently needs to be addressed. Generally speaking, conflicts between forests and water are increasing worldwide, and future research should focus on how to solve current and future conflicts, considering local climates. As agriculture, mining, and urbanization continue to grow, it is expected that the demands for water resources will increase, leading to more conflicts. However, demands for forest-related products will also increase. Furthermore, the establishment, conservation, and management of forests are tasks that most countries should focus on, in order to ensure healthy watersheds. In this sense, activities such as reforestation, afforestation, and land restoration represent a key factor for the future, since worldwide millions of hectares are deforested every year, with many of them becoming deserts. Before concluding, it is worth mentioning gender mainstreaming, even though the topic has not been the focus of this work, when remarking the importance of strengthening forests’ as an effort to work towards poverty reduction, biodiversity conservation and sustainable development. Though gender analysis of forest management for water resources is country specific, generally countries have a clear differentiation between the roles of men to those of women, as typically men are in charge of harvesting and manufacturing wood products, whereas women focus more on fruit collection or similar less intense tasks. A study released by the International Union for Conservation of Nature (IUCN) in the International Year of Forests, 2011, concludes that men and women have different yet complementary knowledge, use and management of the forests. Therefore, in order to achieve sustainable use of forest and land resources, both women and men’s needs, knowledge and experience must be valued and considered. This work suggests that despite there has been progress in women´s access to education employment opportunities in development countries, there is still a marked disparity in forest education, employment and career perspectives in forestry. Results indicate that women have poor access to training programmes, official-decision making process as well as property rights of forests. On the other hand, women play an important role in forest resource management and conservation due to their close dependence on forest resources for subsistence (fuelwood, fodder, herbal medicine among others) and income. A greater focus by future research on the interaction between forest management, water management and gender issues can help to better understand their interconnection and to identify ways to strengthen the management of both resources while fostering gender equality.