Magoosh GRE

The impact of Climatic Change on the Decline of Black French Truffle

| December 10, 2016
  1. Introduction

    1.2 Background

Truffles grow under a very sensitive environment; they naturally occur in the Mediterranean region of Europe. This has been a mysterious crop grown under a veil of secrecy for years in this region of Europe (Ruffles Estate, 2013). This crop is regarded as a delicacy and has sustained its appeal to food lovers all around the world. Truffle are actually a unique edible mushroom that grows underground also regarded as a fungus and is considered a delicacy complimenting the best foods worldwide. Its aroma as well as flavour is commonly described as unique (Ruffles Estate, 2013).  The most preferred quality in truffle market is the black French truffle also known as Tuber melanosporum is one of the most expensive varieties in the market and occurs naturally in parts of France also geographical referred to as the Mediterranean basin (Jolly, 2012). However, the Tuber melanosporum is becoming scarcer, and there is a common idea that this scarcity is due to global change of the climate (Jolly, 2012). This has led to a sharp price increase of this rare commodity, but most of all is the concern of the gradual decline in its availability.  Europe, and more so, the Mediterranean basin has seen a steady decline of this rare species over the last 40 years (FAIR, 2000). This decline has been both in quantity, as well as quality, however this paper will examine the former.

1.3 Project Aims and Objectives

This project’s principle aim is to collect and analyse data using both quantitative and qualitative methods to understand the increasing decline in the production of black truffles from France also referred to as Périgord truffle and Tuber melanosporum.  In this regard, the project will adopt cause-effect deductions, hypothesis testing, and observations to develop understanding this decline in truffle production and in particular whether it affects the natural occurring or cultivated truffles. A secondary aim of this project considers the reasons for the decline of production of the black French truffle. This project, through careful analysis of related research acknowledges the fact that there is a general decline in natural occurring truffle and that this decline is associated with various factors. The study seeks to identify the main reason for the decline in production and harvesting of black French truffles.  The study also aims at providing recommendations to address the decline in truffle production. This study will be documented accurately in order to provide subsequent researchers with all the information necessary to further the development in this field of study.

  1. Literature Review

In consideration of Truffles biological and ecological growth and development Smith and  Read (1997), assert that root symbionts are most significant in checking the ecosystem function  in most temperate forests of the world, and this includes the rare ectomycorrhizal fungi.  Their main function is the provision of the much needed trace minerals to the truffles as well as protection from drought, disease causing agents and pests (Garbaye, 2000; Govindarajulu et al., 2005). Smith and Read (1997) further add that truffles reciprocate provision of food and protection from disease with provision of carbon to the micro-organisms. The ecology in these temperate regions is complexly interconnected, the mushrooms that are produced by the micro-organisms and are significant sources of food for the animal populations in the forests (Carey et al., 2000).

However, according to FAIR (2000), the black truffles production in Europe has dramatically declined over the last half century, this is both in quality as well as quantity.  Furthermore, efforts have been made to increase the vegetation that promote truffle growth, but the decline has persisted.  This trend had been identified earlier by Cherfas (1991), and in his research, he claimed that the decline had begun over 100 years ago in the natural habitat, in the temperate forests. The cause of this decline in the growth and development of black truffles has been the subject of inquiries and research. There is still little explanation for these long term decline in both natural and cultivated  truffle.   Research is needed to help understand this decline, the real difficulty lay in understanding the underground microbial since experimental environments fail to match the necessary real world conditions (Macdonald et al., 2005). As a matter of fact Lamon et al (2009) agree that there is scarcity of much needed extended observations of quantitative data generated from natural the natural setting.

Chevalier et al. ( 2001), assert  that  both Tuber melanosporum and Tuber magnatum are the most valuable species in the market. These varieties are also the endangered species at the brink of extinction. Hall et al. (2001), in their findings explain that geographically, Tuber melanosporum naturally occurs  in France, Italy, Bulgaria and certain areas in Europe.  Martin, F. et al (2010), specifically examines the decline in the production of Tuber melanosporum, however, he also adds that they naturally occur in the Mediterranean  habitat.  Sourzat (2002), in the french publication, explains that T. melanosporum’s fruits best in its natural setting characterized by rocks, forests that are open that are generally warm with mild winter seasons, as well, as regular precipitation in the summers. In addition, best production is expected on the slopes where the produce receives protection from excessive cold and dry wind. According to Hall et al. (2001), research reveals that truffières grown in rainy areas with lower temperatures and have not yielded any truffles. In fact, truffles of the T. melanosporum species grew best in climatic regions with between 600-1500 mm average precipitations, average temperatures of 18-21 degree Celsius in the summer and the winter, an average of 1-8 degree Celsius (Zambonelli & Di Munno, 1992). It seems areas that continuously have frozen ground in the cold seasons are not suited for the growth of T. melanosporum because the fruits spoil when frozen.

Fontana and Bonfante (1971) in their publication introduce the idea of growing truffle fungi in an artificial environment. They explain that this idea was to supplement the deficit of the produce collected in the natural habitat. This method was developed back in the 1970s indication that the decline of truffle had already been the cause of concern in the market. By the turn of the millennium,  truffle grown in orchards accounted for half of the truffle produced around the world (Hall et al., 2003). It also important to note that a majority of these orchards are developed within truffles natural geographic areas.

Having highlighted the required natural habitats for the truffles, and in reference to their decline, there are several suggestions based on various research on this decline.  Cherfas (1991) traces back the history of this decline by asserting that the number of mushroom species gathered in every foray dropped from 72 to 38 between 1912 and 1982 in the Netherlands.  In the same publication, it is revealed that chanterelles in central European market in mid 1970s were found to have reduced in size 50 times than those in 1950s. Hall et al.(2003) in their publication reveal that, by the 20th Century, T. melanosporum in the French market had dropped to 2000 tons annually and a further decline was witnessed by the turn of the 21st Century by 150 tons. It is true that the truffle harvesting in France has been an affair by a small number of people who mainly collected them from their natural setting. As seen in the previous paragraph, there is an increase in production of truffles in orchards as a supplement to the dwindling natural supply. In a later publication Hall et al., (2007), affirm that the decline in natural truffle harvest has persisted and is at an all time low of between 12 to 150 tonnes per year from the 1000 to 2000 tonnes in the 1990s. The steady decline in the production of  truffle has led to the rise in price per unit over the last decade with an increase in demand (Lee, 2008).

The decline of French Truffle has been a point of concern in the scientific research circles with some as Hall et al. (2003) in their study, pointing at water and air pollution, in addition to other factors including, the dynamism in forest structure and the lack of knowledge in traditional gathering as a result of world wars. Similar findings have been published in a report by Amaranthus (2007) citing destruction of truffle natural habitat, urban development, among the reasons for the decline. Such factors are most likely to continue reducing the production figures and specifically those in their natural settings (Amaranthus, 2007; Hall et al., 2007).  Garvey and Cooper (2004), in their report further allude that this decline in natural habitat has resulted in the production of truffles on cultivated farms where the trees or truffières are inoculated. However, these remedies cannot beat the native oak and hazel vegetation as the major producer of the French black truffles in France.

In the recent years, the decline in truffle has been experienced in many regions of the world and especially the fast declining French black truffle or the Tuber melanosporum. However, it appears that most researchers are turning to climate as the main culprit. Büntgen et al.(2012) in their study on drought induced truffle decline explains the effect of climate on the  production of truffle.  They claim in their research that the effect of climate can either be directly or through the truffles symbiotic host vegetation. This literature review delves much into this article because of its relevance to the topic. Büntgen et al. (2012), provide in depth review on the yearly inventory of regional collection of truffle from Spain consisting of Aragón, France mainly a Périgord or Tuber melanosporum, and Italy a combination of Piedmont and Umbria.  In this analysis, they indicate that the change in truffle production between 1970 and 2006 was similar between the species from Spain and France that is Aragón and Périgord respectively. Their analysis also found a lack of similarities in changes of production between Périgord and Piedmont–Umbria from France and Italy respectively. This observation from the regional-scale coherency is consistent with Sourzat (2002) observation that western mediterranean basin is the home of truffle fruiting.  In addition, the harvests of Aragón and Périgord have revealed significant correlation, this the authors relate to the similarity in summer precipitation, whereas lack of correlations was found between Piedmont and Umbria production and precipitation (Büntgen et al., 2012). The difference in levels of sensitivity here is understandable because the Piedmont and Umbria experience double summer precipitation than Spanish Aragón with Périgord ranging in between (Zambonelli & Di Munno, 1992). The average of  the three, truffle production outcomes, their regional mean correlated both positively and negatively at higher significant level of 99.9 percent with between June and August rainfall totals as well as maxima temperatures.

The authors, Büntgen et al.(2012), posits in their analysis that both the natural and the cultivated truffles in the Mediterranean are seasonal and are subjected to the season between November and February a claim supported by Mello et al., (2006).  In addition, this is dependent on the summer condition with rainy and cold weather instrumental in the fruit body development as supported by Gallot, (1999) in his publication more than a decade prior to Büntgen et al., (2012).  Büntgen et al. (2012) postulate that given the relationship between fungi and host vegetation, there is bound to be competition for moisture due to the amount of rainfall in this season and this correlate significantly at 99.9 percent level with the yield. Fischer and Schär, (2010) present a suite of a dozen climatic models leading to rise in mean temperatures and decrease in rainfall totals for the Mediterranean region until the end of the 21st Century. This is indicative of the increased summer evapotranspiration. It is interesting to note that the simulated southwest European climatic conditions representing the last ten years are consistent to the drop in the production of truffle harvest (Büntgen et al., 2012).  Nonetheless, Büntgen et al. (2012),  state that it is unclear whether the truffle will reach tipping points as a result of the projected shift in climate, this is regard to their physiological and biogeochemical fruit body development. In their assumption, the expected or projected summer dryness will result in a sustained decline, in truffle yield, while the regions north of Alpine arc are most likely to provide suitable habitat for the truffle due to their calcareousness. Based on their observations, Büntgen et al.(2012), are inclined to the idea that climatic change and more so reduced summer precipitation and  increased temperatures are the cause for truffle yields in the Mediterranean basin the natural habitat of T. melanosporum. Mello et al. (2006), in their analysis claim that the reduction in future summer rainfall coupled with summer aridity will result in drought resistant strain of T. melanosporum within its natural setting or distribution range. Samils, et al, (2008) in their research predict that the expected drop in truffle harvest in the Mediterranean  region, will have a significant impact not only on  the local tourism, but the agriculture as well as the global prices of this valuable commodity.  This is most likely to increase the value of other varieties with artificial metabolism and not specific to the requirements of their ecological niche  as the T. melanosporum (Mello et al., 2006;Gallot, 1999). This might see an increase in T. aestivum cultivation in areas where traditionally T. melanosporum was predominant as well as an increase in demand of truffle from non-traditional T. melanosporum producing regions outside Europe (Büntgen et al., 2012).

Splivallo et al. (2012), in their analysis of the Burgundy truffle, suggest that the change in climatic conditions that were said to have begun a century ago has no impact on the current burgundy truffle distribution.  However, they concur with Büntgen et al.(2012) on the impact of climatic change on species with narrower ranges such as the French black truffle, Périgord or Tuber melanosporum, and Italy a combination of Piedmont and Umbria. They support this by claiming that if the climate fails to restrict the distribution of these two species, then even a slight temperature increase in northern Europe as predicted by Büntgen et al. (2012) might result in its northern expansion. They confirm what Chevalier et al.(2001) had outlined that rainfall, soil composition are also factors that contribute to the decline in the production of Périgord. Splivallo et al. (2012), concur with Büntgen et al.(2012) assertion that other options will be needed to avert the looming shortage of this truffle species,  success cultivation lies in orchard farming as a change from the current empirical practices. They claim that cultivation of truffle in a bid to mitigate the effects of climate change which is a major cause of the decline should be based on scientific evidence. Therefore, the rise in temperature, in its self, will not be sufficient for the shift of truffle production in the northern European region (Splivallo et al., 2012).

  1. Methodology and Procedure

3.1 Research Design

This study will adopt a mixed methods research design. This process entails collecting and analysing data using both quantitative and qualitative methods to understand the research problem comprehensively. When both qualitative and quantitative methods are combined in research, they supplement each other allowing a comprehensive analysis of the research problem (Tashakkori & Teddlie, 2003). According to Charles & Mertler (2002), quantitative methods deal with numerical data using cause-effect deductions, hypothesis testing, and observations to develop an understanding of the research issue. On the other hand, qualitative methods require the researcher to develop a complete picture of the research issues by conducting an in-depth analysis of words, as well as, compiled reports by the study participants. In this approach, the researcher adopts a constructivist approach to have a complete understanding of the problem centred on different contextual aspects (Charles & Mertler, 2002). In the mixed research methods, the uses pragmatic philosophy by affirming that truth is what works. Therefore, mixed methods integrate both text and numerical data to give a clear overview of the research problem. In this regard, this study will use surveys and interviews since they are the most popular data collection research tools (Creswell, 2002). In the first step of data collection, a web-based survey will be used, and data analysed using discriminant function. The qualitative method will involve semi-structured interviews to collect textual data from people to regarding the decline of Truffles.

3.2  Research Sample

The target population sample will be about 1,200 environmentalists and hoteliers in France regarding the decline of truffles. These individuals are people who have been working in the hotel and environmental sectors in France. For the first quantitative stage of the research, a convenience sample will be chosen comprising individuals studying truffles decline, locals, and environmentalists, as well as, hoteliers. For the qualitative phase of the research, a smaller sample will be used to  understand the main issue regarding the decline of French truffle (Creswell, 2002, p. 194). This is to ensure the selected participants will give appropriate answers to the research questions. Besides, for the qualitative part of the research, participants will be notified of their selection for voluntary follow-up individual interviews. Given the use of mixed methods research in the study, selection of participants for the qualitative part will rely on the outcomes of the quantitative stage. The use of this approach will ensure the researcher gets a multidimensional outlook of the research problem. For this research, the participants will be chosen centred on the statistically significant difference outcomes of the discriminant function analysis.

3.3 Data Collection

For the quantitative phase of the research, a cross-sectional survey will be used; this implies that statistics will be gathered at one point in time (McMillan, 2000). The survey used for this research will be of different formats including multiple choices, yes/no questions, self-evaluation items, and open-ended questions. The questionnaire will comprise twenty four questions divided equally into six sections. The first section will contain questions regarding truffles and the participant’s understanding of truffles measured on a 7-point Likert scale. The second part will evaluate the participants’ awareness regarding the decline of truffles using a 7-point scale. The third part will provide information regarding the factors participants believe to cause a decline in truffles. The current issues regarding management of truffles will constitute the fourth part while the fifth segment will provide data answering how ecological factors influence truffles survival. Demographic questions will be in the sixth part of the survey regarding data about the participants’ age, residency, gender, and employment among others. Besides, the final question in the survey will be open-ended asking for additional information about truffles decline in France. The survey will be web-based accessible through a URL address given to the participants.

For the qualitative method, in-depth semi-structured face-to-face interviews will be used to collect data. Half of the research sample will be interviewed regarding the research question. Historical texts will be further used to validate the data collected from the interviews. The interviews will include twenty open-ended questions pilot-tested before the interviews. The interviews questions will be formulated based on the results from the quantitative method. During the interview, the participants will be debriefed to obtain reliable information for the interview questions though, they will be issued with the questions prior to the interviews. The interviews will be tape recorded with the participants’ consent and a copy of the transcript emailed to them after the interview. The respondents will also be allowed to review their answers for the interview transcripts to ascertain their correctness.

3.4 Data Analysis

Prior to the statistical analysis of the survey results, the data will be screened on both univariate and multivariate levels. This will help the research detect any multicollinearity in the collected data. Any data that shows a high probability in another category will be excluded during the analysis since they may give a poor model fit (Tabachnick & Fidell, 2000). The research’s data screening will entail descriptive statistics for the variables, linearity and homoscedasticity, normality, multivariate outliers, multicollinearity and singularity. The descriptive statistics will be tabulated, and a frequency’s analysis conducted to determine the validity of the survey questions. The discriminant function analysis will be used to determine the proportion by which the variables differ, and classify the functions into predictable groups. The results will then be reported in the form of discussion. Nonetheless, all the statistical analyses will be conducted using Statistical Package for Social Sciences software (SPSS) version 11.0.

In most qualitative research, data collection and analysis progress concurrently. For the qualitative analysis, data collected from the interviews will be coded and analysed for premises using the Qualitative Software and Research (QSR) N6 for qualitative data analysis. Furthermore, a visual data display will be used to identify the relationship in the data collected from the interviews. Data analysis for this phase of the research will involve creating a comprehensive description of the results; the researcher situates the cases in its context to make the case descriptions, and premises related to particular activities in the study’s outcomes (Creswell & Maitta, 2002). The researcher will construe the meaning of the results and describe them in the discussion section of the research proposal.


Amaranthus, M., 2007. Independent Truffle Expert’s Report in Product Disclosure Statement for

 the Oak Valley Truffle Project. Oak Valley Project.

Büntgen, U. et al., 2012. Drought-induced decline in Mediterranean truffle harvest. Nature

            Climate Change, 2, pp.827-29.

Carey, A.B., Colgan, W., Trappe, J.M. & Molina, R., 2000. Effects of forest management on

truffle abundance and squirrel diets. Northwest Science , 76, pp.148–57.

Charles, C.M. & Mertler, C.A., 2002. Introduction to educational research. 4th ed. Boston, MA:

Allyn and Bacon.

Cherfas, J., 1991. Disappearing mushrooms: Another mass extinction?. Science, pp.254: 1448.

Chevalier, G., Gregori, G., Frochot, H. & Zambonelli, A., 2001. The cultivation of the Burgundy

truffle. In Proc Second Intl Conf on Edible Mycorrhizal Mushrooms. Christchurch: Crop & Food Research Limited. pp.1-12.

Creswell, J.W., 2002. Educational research: Planning, conducting, and evaluating quantitative

and qualitative approaches to research. Upper Saddle River, NJ: Merrill/Pearson Education.

Creswell, J.W. & Maitta, R., 2002. Qualitative research. In N. Salkind, ed. Handbook of research

            design and social measurement. Thousand Oaks, CA: Sage Publications. pp.143-84.

FAIR, 2000. Improvement of the organoleptic quality of European truffles (EUROTRUFFE).

Cooperative Research Measures.

Fischer, E.M. & Schär, C., 2010. Nature. Geoscience, 3, pp.398–403.

Fontana, A. & Bonfante, P., 1971. Mycorrhizal synthesis between Tuber brumale Vitt.and Pinus

nigra Arnold. Allionia, 17, pp.15-18.

Gallot, G., 1999. La truffe. INRA.

Garbaye, J., 2000. The role of ectomycorrhizal symbiosis in the resistance of forests to water

stress. Outlook on Agriculture , 29, pp.63-69.

Garvey, D. & Cooper, P., 2004. Increasing the productivity of truffières in Tasmania. RIRDC.

Govindarajulu, M. et al., 2005. Nitrogen transfer in the arbuscular mycorrhizal symbiosis. Nature

            , 435, pp.819-23.

Hall, I.R., Brown, G.T. & Zamboneli, A., 2007. Taming the Truffle. The History Lore and

            Science of the Ulimate Mashroom. Timber Press.

Hall, I., Byars, J. & Brown, G., 2001. The Black Truffle: Its History, Uses and Cultivation.

Christchurch: New Zealand Institute for Crop & Food Research Limited.

Hall, I., Yun, W. & Amicucci, A., 2003. Cultivation of edible ectomycorrhizal mushrooms.

Trends in Biotechnology, 21, pp.433–438.

Jolly, D., 2012. $1,200 a Pound, Truffles Suffer in the Heat. [Online] Available at: [Accessed 2 December 2013].

Lamon, L. et al, 2009. Environmental Science Technology, 43, pp.5818–5824.

Lee, B., 2008. Taking Stock of the Australian Truffle Industry. Barton: Canprint.

Macdonald, R.W., Harner, T. & Fyfe, 2005. Macdonald, R. W., Harner, T. & Fyfe, J. Sci. Total

Environ. J. Sci. Total Environ., 342, pp.5–86.

Martin, F. et al, 2010. Tuber melanosporum. Nature , 464, pp.1033–38.

McMillan, J.H., 2000. Educational research: Fundamentals for the consumer. 3rd ed. New

York: Addison-Wesley Longman.

Mello, A., Murat, C. & Bonfante, P., 2006. FEMS Microbiol.. Lett, 260, pp.1–8.

Ruffles Estate, 2013. An Internationally Recognised Gourmet Experience. [Online] Ruffles

Estate Available at:  HYPERLINK “”  [Accessed 2 December 2013].

Samils, et al, 2008. Econ. Bot., 62, pp.331–40.

Smith, S. & Read, D.J., 1997. Mycorrhizal Symbiosis. London: Academic Press.

Sourzat, P., 2002. Guide pratique de trufficulture. Station d’expérimentation sur la truffe. Le

Montat: Lyćee professionnel agricole et viticole de Cahors.

Splivallo, R. et al., 2012. Is climate change altering the geographic distribution of truffles. Front

 Ecol Environ, 10, pp.461–62.

Tabachnick, B.G. & Fidell, L.S., 2000. Using multivariate statistics. New York: Allyn & Bacon.

Tashakkori, A. & Teddlie, C., 2003. Handbook on mixed methods in the behavioral and social

            sciences. Thousand Oaks, CA: Sage Publications.

Zambonelli, A. & Di Munno, R., 1992. Indagine sulla possibilitá di diffusione dei

rimboschimenti con specie tartufigene: aspetti tecnico-colturali ed economici. Ministero dell’Agricoltura e delle Foreste.

Tags: , ,

Category: Environmental Science, Research Proposal Examples